The 100 most-cited articles in Astronomy and Astrophysics, 2024

The current standard model of cosmology successfully describes a variety of measurements, but the nature of its main ingredients, dark matter and dark energy, remains unknown. Euclid is a medium-class mission in the Cosmic Vision 2015–2025 programme of the European Space Agency (ESA) that will provide high-resolution optical imaging, as well as near-infrared imaging and spectroscopy, over about 14 000 deg 2 of extragalactic sky. In addition to accurate weak lensing and clustering measurements that probe structure formation over half of the age of the Universe, its primary probes for cosmology, these exquisite data will enable a wide range of science. This paper provides a high-level overview of the mission, summarising the survey characteristics, the various data-processing steps, and data products. We also highlight the main science objectives and expected performance.

The eROSITA telescope array aboard the Spektrum Roentgen Gamma (SRG) satellite began surveying the sky in December 2019, with the aim of producing all-sky X-ray source lists and sky maps of an unprecedented depth. Here we present catalogues of both point-like and extended sources using the data acquired in the first six months of survey operations (eRASS1; completed June 2020) over the half sky whose proprietary data rights lie with the German eROSITA Consortium. We describe the observation process, the data analysis pipelines, and the characteristics of the X-ray sources. With nearly 930 000 entries detected in the most sensitive 0.2–2.3 keV energy range, the eRASS1 main catalogue presented here increases the number of known X-ray sources in the published literature by more than 60%, and provides a comprehensive inventory of all classes of X-ray celestial objects, covering a wide range of physical processes. A smaller catalogue of 5466 sources detected in the less sensitive but harder 2.3–5 keV band is the result of the first true imaging survey of the entire sky above 2 keV. We…

Spectroscopy with the James Webb Space Telescope has opened the possibility of identifying moderate-luminosity active galactic nuclei (AGNs) in the early Universe, at and beyond the epoch of re-ionisation, complementing previous surveys of much more luminous (and much rarer) quasars. We present 12 new AGNs at 4 < z < 7 in the JADES survey (in addition to the previously identified AGN in GN-z11 at z = 10.6) revealed through the detection of a broad-line region (BLR) seen in the Balmer emission lines. The depth of JADES, together with the use of three different spectral resolutions, enables us to probe a lower-mass regime relative to previous studies. In a few cases, we find evidence for two broad components of H α , which suggests that these could be candidate merging black holes (BHs), although a complex BLR geometry cannot be excluded. The inferred BH masses range from 8 × 10 7 M ⊙ down to 4 × 10 5 M ⊙ , interestingly probing the regime expected for direct collapse BHs. The inferred AGN bolometric luminosities (∼10 44 − 10 45 erg/s) imply accretion rates that are < 0.5 times the…

The European Pulsar Timing Array (EPTA) and Indian Pulsar Timing Array (InPTA) collaborations have measured a low-frequency common signal in the combination of their second and first data releases, respectively, with the correlation properties of a gravitational wave background (GWB). Such a signal may have its origin in a number of physical processes including a cosmic population of inspiralling supermassive black hole binaries (SMBHBs); inflation, phase transitions, cosmic strings, and tensor mode generation by the non-linear evolution of scalar perturbations in the early Universe; and oscillations of the Galactic potential in the presence of ultra-light dark matter (ULDM). At the current stage of emerging evidence, it is impossible to discriminate among the different origins. Therefore, for this paper, we consider each process separately, and investigated the implications of the signal under the hypothesis that it is generated by that specific process. We find that the signal is consistent with a cosmic population of inspiralling SMBHBs, and its relatively high amplitude can be…

We analysed the gas-phase metallicity properties of a sample of low-stellar-mass (log M ⋆ / M ⊙ ≲ 9) galaxies at 3 < z < 10 observed with JWST/NIRSpec as part of the JADES programme in its deep GOODS-S tier. By combining this sample with more massive galaxies at similar redshifts from other programmes, we study the scaling relations between stellar mass ( M ⋆ ), oxygen abundance (O/H), and star-formation rate (SFR) for 146 galaxies spanning three orders of magnitude in stellar mass and out to the epoch of early galaxy assembly. We find evidence for a shallower slope at the low-mass end of the mass–metallicity relation (MZR), with 12+log(O/H) = (7.72 ± 0.02) + (0.17 ± 0.03) log( M ⋆ /10 8 M ⊙ ), in good agreement with the MZR probed by local analogues of high-redshift systems, such as the ‘Green Pea’ and ‘Blueberry’ galaxies. The inferred slope is well matched by models including ‘momentum-driven’ supernova (SN) winds, suggesting that feedback mechanisms in dwarf galaxies (and at high z ) might be different from those in place at higher masses. The evolution in the normalisation is…

We describe the NIRSpec component of the JWST Deep Extragalactic Survey (JADES), and provide deep spectroscopy of 253 sources targeted with the NIRSpec micro-shutter assembly in the Hubble Ultra Deep Field and surrounding GOODS-South. The multi-object spectra presented here are the deepest so far obtained with JWST, amounting to up to 28 hours in the low-dispersion (R~30–300) prism, and up to 7 hours in each of the three medium-resolution R ≈ 1000 gratings and one high-dispersion grating, G395H (R ≈ 2700). Our low-dispersion and medium-dispersion spectra cover the wavelength range 0.6–5.3 μm. We describe the selection of the spectroscopic targets, the strategy for the allocation of targets to micro-shutters, and the design of the observations. We present the public release of the reduced 2D and 1D spectra, and a description of the reduction and calibration process. We measure spectroscopic redshifts for 178 of the objects targeted extending up to z = 13.2. We present a catalogue of all emission lines detected at S/N > 5, and our redshift determinations for the targets. Combined with…

Context. The census of open clusters has exploded in size thanks to data from the Gaia satellite. However, it is likely that many of these reported clusters are not gravitationally bound, making the open cluster census impractical for many scientific applications. Aims. We aim to test different physically motivated methods for distinguishing between bound and unbound clusters, using them to create a cleaned star cluster catalogue. Methods. We derived completeness-corrected photometric masses for 6956 clusters from our earlier work. Then, we used these masses to compute the size of the Roche surface of these clusters (their Jacobi radius) and distinguish between bound and unbound clusters. Results. We find that only 5647 (79%) of the clusters from our previous catalogue are compatible with bound open clusters, dropping to just 11% of clusters within 250 pc. Our catalogue contains 3530 open clusters in a more strongly cut high-quality sample of objects. The moving groups in our sample show different trends in their size as a function of age and mass, suggesting that they are unbound…

Context. High-resolution 3D maps of interstellar dust are critical for probing the underlying physics shaping the structure of the interstellar medium, and for foreground correction of astrophysical observations affected by dust. Aims. We aim to construct a new 3D map of the spatial distribution of interstellar dust extinction out to a distance of 1.25 kpc from the Sun. Methods. We leveraged distance and extinction estimates to 54 million nearby stars derived from the Gaia BP/RP spectra. Using the stellar distance and extinction information, we inferred the spatial distribution of dust extinction. We modeled the logarithmic dust extinction with a Gaussian process in a spherical coordinate system via iterative charted refinement and a correlation kernel inferred in previous work. In total, our posterior has over 661 million degrees of freedom. We probed the posterior distribution using the variational inference method MGVI. Results. Our 3D dust map has an angular resolution of up to 14′ ( N side = 256), and we achieve parsec-scale distance resolution, sampling the dust in 516…

Clusters of galaxies can be used as powerful probes to study astrophysical processes on large scales, test theories of the growth of structure, and constrain cosmological models. The driving science goal of the SRG/eROSITA All-Sky Survey is to assemble a large sample of X-ray clusters with a well-defined selection function to determine the evolution of the mass function and, hence, the cosmological parameters. We present here a catalog of 12 247 optically confirmed galaxy groups and clusters detected in the 0.2–2.3 keV as extended X-ray sources in a 13 116 deg 2 region in the western Galactic half of the sky, which eROSITA surveyed in its first six months of operation. The clusters in the sample span the redshift range 0.003 < z < 1.32. The majority (68%) of these clusters, 8361 sources, represent new discoveries without known counterparts in the literature. The mass range of the sample covers three orders of magnitude from 5 × 10 12 M sun to 2 × 10 15 M sun . We construct a sample for cosmology with a higher purity level (~95%) than the primary sample, comprising 5259 securely…

We explore the kinematic gas properties of six 5.5 < z < 7.4 galaxies in the JWST Advanced Deep Extragalactic Survey (JADES), using high-resolution JWST/NIRSpec multi-object spectroscopy of the rest-frame optical emission lines [O III ] and H α . The objects are small and of low stellar mass (∼1 kpc; M * ∼ 10 7 − 9 M ⊙ ), less massive than any galaxy studied kinematically at z > 1 thus far. The cold gas masses implied by the observed star formation rates are about ten times higher than the stellar masses. We find that their ionised gas is spatially resolved by JWST, with evidence for broadened lines and spatial velocity gradients. Using a simple thin-disc model, we fit these data with a novel forward-modelling software that accounts for the complex geometry, point spread function, and pixellation of the NIRSpec instrument. We find the sample to include both rotation- and dispersion-dominated structures, as we detect velocity gradients of v ( r e )∼100 − 150 km s −1 , and we find velocity dispersions of σ 0 ∼ 30 − 70 km s −1 that are comparable to those at cosmic noon. The dynamical…

Context . Complex organic molecules (COMs) are ubiquitously detected in the gas phase and thought to be mostly formed on icy grains. Nevertheless, there have not been any unambiguous detections of COMs larger than CH 3 OH in ices reported thus far. Exploring this matter in greater detail has now become possible with the unprecedented possibilities offered by the James Webb Space Telescope (JWST) within the infrared (IR) spectral range with its very high sensitivity and spectral resolution in the critical 5–10 µm range, the fingerprint region of oxygen-bearing COMs. Aims . In the JWST Observations of Young protoStars (JOYS+) program, more than 30 protostars are undergoing observation with the Medium Resolution Spectrograph (MRS) of the Mid-IR Instrument (MIRI). The goal of this study is to comprehensively explore the COMs ice signatures in one low- and one high-mass protostar: NGC 1333 IRAS 2A and IRAS 23385+6053, respectively. Methods . We performed global continuum and silicate subtractions of the MIRI-MRS spectra, followed by a local continuum subtraction in optical depth scale in…

Context. Gravitational waves from black-hole (BH) merging events have revealed a population of extra-galactic BHs residing in short-period binaries with masses that are higher than expected based on most stellar evolution models – and also higher than known stellar-origin black holes in our Galaxy. It has been proposed that those high-mass BHs are the remnants of massive metal-poor stars. Aims. Gaia astrometry is expected to uncover many Galactic wide-binary systems containing dormant BHs, which may not have been detected before. The study of this population will provide new information on the BH-mass distribution in binaries and shed light on their formation mechanisms and progenitors. Methods. As part of the validation efforts in preparation for the fourth Gaia data release (DR4), we analysed the preliminary astrometric binary solutions, obtained by the Gaia Non-Single Star pipeline, to verify their significance and to minimise false-detection rates in high-mass-function orbital solutions. Results. The astrometric binary solution of one source, Gaia BH3, implies the presence of a…

The evolution of the cluster mass function traces the growth of linear density perturbations, providing valuable insights into the growth of structures, the nature of dark matter, and the cosmological parameters governing the Universe. The primary science goal of eROSITA, on board the Spectrum Roentgen Gamma (SRG) mission, is to constrain cosmology through the evolution of the cluster mass function. In this paper, we present a set of cosmological constraints obtained from 5259 clusters of galaxies detected over an area of 12791 deg 2 in the western Galactic hemisphere of eROSITA’s first All-Sky Survey (eRASS1). The common footprint region (4968 deg 2 ) between the eROSITA Survey and Dark Energy Survey (DES), the Kilo-Degree Survey (KiDS), and the Hyper Supreme Camera (HSC) survey is used for calibration of the scaling between X-ray count rate of the clusters and their total mass through measurements of their weak gravitational lensing signal. The eRASS1 cluster abundances constrain the ΛCDM parameters, namely, the energy density of the total matter to Ω m = 0.29 −0.02 +0.01 and the…

The Near-Infrared Spectrometer and Photometer (NISP) on board the Euclid satellite provides multiband photometry and R ≳ 450 slitless grism spectroscopy in the 950–2020 nm wavelength range. In this reference article, we illuminate the background of NISP’s functional and calibration requirements, describe the instrument’s integral components, and provide all its key properties. We also sketch the processes needed to understand how NISP operates and is calibrated as well as its technical potentials and limitations. Links to articles providing more details and the technical background are included. The NISP’s 16 HAWAII-2RG (H2RG) detectors with a plate scale of 0″.3 pixel −1 deliver a field of view of 0.57 deg 2 . In photometric mode, NISP reaches a limiting magnitude of ~24.5 AB mag in three photometric exposures of about 100 s in exposure time for point sources and with a S/N of five. For spectroscopy, NISP’s pointsource sensitivity is a signal-to-noise ratio = 3.5 detection of an emission line with flux ~2 × 10 −16 erg s −1 cm −2 integrated over two resolution elements of 13.4 Å in…

Context. One of the surprising early findings with JWST has been the discovery of a strong “roll-over” or a softening of the absorption edge of Ly α in a large number of galaxies at z ≳ 6, in addition to systematic offsets from photometric redshift estimates and fundamental galaxy scaling relations. This has been interpreted as strong cumulative damped Ly α absorption (DLA) wings from high column densities of neutral atomic hydrogen (H I ), signifying major gas accretion events in the formation of these galaxies. Aims. To explore this new phenomenon systematically, we assembled the JWST/NIRSpec PRImordial gas Mass AssembLy (PRIMAL) legacy survey of 584 galaxies at z = 5.0 − 13.4, designed to study the physical properties and gas in and around galaxies during the reionization epoch. Methods. We characterized this benchmark sample in full and spectroscopically derived the galaxy redshifts, metallicities, star formation rates, and ultraviolet (UV) slopes. We defined a new diagnostic, the Ly α damping parameter D Lyα , to measure and quantify the net effect of Ly α emission strength,…

Context . We explore model-independent constraints on the Universe kinematics up to the snap and jerk hierarchical terms, considering the latest baryon acoustic oscillation (BAO) release provided by the DESI collaboration. Aims . We intend to place novel and more stringent constraints on the cosmographic series, incorporating three combinations of data catalogs: the first made by BAO and observational cosmic chronometers, the second made by BAO and type Ia supernovae, and the last including all the cited data sets. Methods . Considering the latest BAO data provided by the DESI collaboration and tackling the r d parameter to span within the range [144,152] Mpc, with a fixed step of δ r d = 2 Mpc, we employed Monte Carlo Markov chain analyses based on the Metropolis algorithm to fix novel bounds on the cosmographic series, fixing the deceleration, q 0 , the jerk, j 0 , and the snap, s 0 , parameters, up to the 2σ level. A comparison between the results of the Planck satellite with those obtained by the DESI collaboration is also reported. Results . Our findings showcase a significant…

This paper presents the specification, design, and development of the Visible Camera (VIS) on the European Space Agency’s Euclid mission. VIS is a large optical-band imager with a field of view of 0.54 deg 2 sampled at 0″.1 with an array of 609 Megapixels and a spatial resolution of 0″.18. It will be used to survey approximately 14 000 deg 2 of extragalactic sky to measure the distortion of galaxies in the redshift range z = 0.1–1.5 resulting from weak gravitational lensing, one of the two principal cosmology probes leveraged by Euclid . With photometric redshifts, the distribution of dark matter can be mapped in three dimensions, and the extent to which this has changed with look-back time can be used to constrain the nature of dark energy and theories of gravity. The entire VIS focal plane will be transmitted to provide the largest images of the Universe from space to date, specified to reach m AB ≥ 24.5 with a signal-to-noise ratio S/N ≥ 10 in a single broad I E ≃ ( r + i + z ) band over a six-year survey. The particularly challenging aspects of the instrument are the control and…

The JWST has ushered in a new era in atmospheric characterisations of temperate low-mass exoplanets with recent detections of carbon-bearing molecules in the candidate Hycean world K2-18 b. We investigated JWST observations of the TOI-270 system, with two sub-Neptunes simultaneously transiting the nearby M dwarf during the visit. We report our atmospheric characterisation of the outer planet TOI-270 d, a candidate Hycean world, with JWST transmission spectroscopy using the NIRSpec G395H instrument in the 2.7–5.2 μm range, combined with previous observations obtained with the HST WFC3 spectrograph (1.1–1.6 μm). The spectrum reveals strong signatures of CH4 and CO2 at 3.8–4.9σ and 2.9–3.9σ confidence, respectively, and no evidence of NH3. The abundant CH4 and CO2, at ∼0.1–1% mixing ratios, and the non-detection of NH3 are similar to the findings reported for K2-18 b and consistent with predictions for a Hycean world with a planet-wide ocean under a H2-rich atmosphere. We also report evidence of CS2 at a 2.3–3.0σ confidence and a potential inference of H2O at 1.6–4.4σ, depending on the…

Finding the emergence of the first metals in the early Universe and identifying their origin are some of the most important goals of modern astrophysics. We present deep JWST/NIRSpec spectroscopy of GS-z12, a galaxy at z = 12.5, in which we report the detection of the C III ] λλ 1907,1909 nebular emission line. This represents the most distant detection of a metal transition, and the most distant redshift determination based on emission lines. In addition, we report tentative detections of [O II ] λλ 3726,3729 and [Ne III ] λ 3869, and possibly O III ] λλ 1661,1666. By using the accurate redshift obtained from C III ], we can model the Ly α drop to reliably measure an absorbing column density of hydrogen of N H I ≈ 10 22 cm −2 , which is too high for an IGM origin and implies an abundant neutral ISM in GS-z12 or in the CGM around it. We tentatively infer a lower limit for the neutral gas mass of about 10 7 M ⊙ which, compared with the galaxy stellar mass of ∼5 × 10 7 M ⊙ , implies a gas fraction higher than about 0.2–0.5. By comparing the measured emission lines with model-based…

In April 2019, the Event Horizon Telescope (EHT) Collaboration reported the first-ever event-horizon-scale images of a black hole, resolving the central compact radio source in the giant elliptical galaxy M 87. These images reveal a ring with a southerly brightness distribution and a diameter of ∼42 μas, consistent with the predicted size and shape of a shadow produced by the gravitationally lensed emission around a supermassive black hole. These results were obtained as part of the April 2017 EHT observation campaign, using a global very long baseline interferometric radio array operating at a wavelength of 1.3 mm. Here, we present results based on the second EHT observing campaign, taking place in April 2018 with an improved array, wider frequency coverage, and increased bandwidth. In particular, the additional baselines provided by the Greenland telescope improved the coverage of the array. Multiyear EHT observations provide independent snapshots of the horizon-scale emission, allowing us to confirm the persistence, size, and shape of the black hole shadow, and constrain the…

We introduce the new TNG-Cluster project, an addition to the IllustrisTNG suite of cosmological magnetohydrodynamical simulations of galaxy formation. Our objective is to significantly increase the statistical sampling of the most massive and rare objects in the Universe: galaxy clusters with log( M 200c / M ⊙ ) ≳ 14.3 − 15.4 at z = 0. To do so, we re-simulate 352 cluster regions drawn from a 1 Gpc volume that is 36 times larger than TNG300, keeping the IllustrisTNG physical model entirely fixed as well as the numerical resolution. This new sample of hundreds of massive galaxy clusters enables studies of the assembly of high-mass ellipticals and their supermassive black holes (SMBHs), brightest cluster galaxies (BCGs), satellite galaxy evolution and environmental processes, jellyfish galaxies, intracluster medium (ICM) properties, cooling and active galactic nuclei (AGN) feedback, mergers and relaxedness, magnetic field amplification, chemical enrichment, and the galaxy-halo connection at the high-mass end, with observables from the optical to radio synchrotron and the…

Context . JWST has taken the sharpest and most sensitive infrared (IR) spectral imaging observations ever of the Orion Bar photodis-sociation region (PDR), which is part of the nearest massive star-forming region the Orion Nebula, and often considered to be the ‘prototypical’ strongly illuminated PDR. Aims . We investigate the impact of radiative feedback from massive stars on their natal cloud and focus on the transition from the H II region to the atomic PDR – crossing the ionisation front (IF) –, and the subsequent transition to the molecular PDR – crossing the dissociation front (DF). Given the prevalence of PDRs in the interstellar medium and their dominant contribution to IR radiation, understanding the response of the PDR gas to far-ultraviolet (FUV) photons and the associated physical and chemical processes is fundamental to our understanding of star and planet formation and for the interpretation of any unresolved PDR as seen by JWST. Methods . We used high-resolution near-IR integral field spectroscopic data from NIRSpec on JWST to observe the Orion Bar PDR as part of the…

Aims. We extend the analysis of a physical model within the standard cosmology that robustly predicts a high star-formation efficiency (SFE) in massive galaxies at cosmic dawn due to feedback-free starbursts (FFBs). This model implies an excess of bright galaxies at z ​ ≳ ​10 compared to the standard models based on the low SFE at later epochs, an excess that is indicated by JWST observations. Methods. Here we provide observable predictions of galaxy properties based on the analytic FFB scenario. These can be compared with simulations and JWST observations. We use the model to approximate the SFE as a function of redshift and mass, assuming a maximum SFE of ϵ max ​ = ​0.2 − 1 in the FFB regime. From this, we derive the evolution of the galaxy mass and luminosity functions as well as the cosmological evolution of stellar and star-formation densities. We then predict the star-formation history (SFH), galaxy sizes, outflows, gas fractions, metallicities, and dust attenuation, all as functions of mass and redshift in the FFB regime. Results. The major distinguishing feature of the model…

JWST has revealed a class of numerous, extremely compact sources with rest-frame red optical/near-infrared (NIR) and blue ultraviolet (UV) colours nicknamed ‘little red dots’. We present one of the highest signal-to-noise ratio JWST NIRSpec prism spectra of a little red dot, J0647_1045 at z = 4.5319 ± 0.0001, and examine its NIRCam morphology to differentiate the origin of the UV and optical/NIR emission and elucidate the nature of the little red dot phenomenon. J0647_1045 is unresolved (re ≲ 0.17 kpc) in the three NIRCam long-wavelength filters but significantly extended (re = 0.45 ± 0.06 kpc) in the three short-wavelength filters, indicating a red compact source in a blue star-forming galaxy. The spectral continuum shows a clear change in slope, from blue in the optical/UV to red in the rest-frame optical/NIR, which is consistent with two distinct components fit by power laws with different attenuations: AV = 0.38 ± 0.01 (UV) and AV = 5.61 ± 0.04 (optical/NIR). Fitting the Hα line requires both broad (full width at half maximum of ∼4300 ± 100 km s−1) and narrow components, but…

We investigate the incidence and properties of ionised gas outflows in a sample of 52 galaxies with stellar masses between 107 M⊙ and 109 M⊙ observed with ultra-deep JWST/NIRSpec MSA spectroscopy as part of the JWST Advanced Deep Extragalactic Survey (JADES). The high-spectral resolution (R2700) NIRSpec observations allowed us to identify for the first time the potential signature of outflows in the rest-frame optical nebular lines in low-mass galaxies at z > 4. The incidence fraction of ionised outflows, traced by broad components, is about 25–40%, depending on the intensity of the emission lines. The low incidence fraction might be due to both the sensitivity limit and the fact that outflows are not isotropic, but have a limited opening angle, which only results in detection when this is directed toward our line of sight. Evidence for outflows increases slightly with stellar mass and star formation rate. The median velocity and mass-loading factor (i.e. the ratio of the mass outflow rate and star formation rate) of the outflowing ionised gas are 350 km s−1 and η = 2.0−1.5+1.6,…

We report the discovery in TMC-1 of two cyano derivatives of the PAH acenaphthylene (C 12 H 8 ). We have found two series of lines with the QUIJOTE line survey that we assign to 1-C 12 H 7 CN and 5-C 12 H 7 CN. For the 1-isomer, we have detected and assigned 173 rotational transitions with J up to 46 and K a up to 9, corresponding to 107 independent frequencies. For the 5-isomer, the identification is based on 56 individual lines, corresponding to 117 rotational transitions with J up to 40 and K a up to 8. Identification of the carriers was achieved through a careful analysis of the derived rotational constants, which permit us to focus on molecules larger than naphthalene but smaller than anthracene and phenanthrene. Moreover, the derived rotational constants indicate that the species are planar; this allows us to discard derivatives of fluorene and acenaphthene, which are non-planar species. Quantum chemical calculations and subsequent chemical synthesis of these molecules, as well as the observation of their rotational transitions in the laboratory, unequivocally support our…

Context.Gaia cannot individually resolve very close binary systems; however, the collected data can still be used to identify them. A powerful indicator of stellar multiplicity is the sources’ reported re-normalised unit weight error (RUWE), which effectively captures the astrometric deviations from single-source solutions. Aims. We aim to characterise the impact of binarity on the RUWE. By flagging potential binary systems based on RUWE, we aim to determine which of their properties will contribute the most to their detectability. Methods. We developed a model to estimate the RUWEs for observations of Gaia sources, based on the biases to the single-source astrometric track arising from the presence of an unseen companion. Then, using the recipes from previous GaiaUnlimited selection functions, we estimated the selection probability of sources with high RUWEs, and discussed what binary properties contribute to increasing the sources’ RUWEs. Results. We computed the maximum RUWE that is compatible with single-source solutions as a function of their location on-sky. We see that binary…

Finding the first generation of stars formed out of pristine gas in the early Universe, known as Population III (PopIII) stars, is one of the most important goals of modern astrophysics. Recent models have suggested that PopIII stars may form in pockets of pristine gas in the halo of more evolved galaxies. We present NIRSpec integral field spectroscopy and micro-shutter array spectroscopic observations of the region around GN-z11, an exceptionally luminous galaxy atz = 10.6, that reveal a greater than 5σdetection of a feature consistent with being HeIIλ1640 emission at the redshift of GN-z11. The very high equivalent width of the putative HeII emission in this clump (log(EWrest(HeII)/Å) = 1.79−0.25+0.15) and a lack of metal lines can be explained in terms of photoionisation by PopIII stars, while photoionisation by PopII stars is inconsistent with the data. The high equivalent width would also indicate that the putative PopIII stars likely have an initial mass function with an upper cutoff reaching at least 500M⊙. The PopIII bolometric luminosity inferred from the HeII line would be…

We present the properties of 17 faint Lyman-α emitting galaxies (LAEs) at z > 5.8 from the JWST Advanced Deep Extragalactic Survey (JADES) spectroscopic data in the Hubble Ultra Deep Field/GOODS-S. These LAEs span a redshift range z ≈ 5.8 − 8.0 and a UV magnitude range MUV ≈ −17 to −20.6, with the Lyα equivalent width (EW) in the range ≈25 − 350 Å. The detection of other rest-optical emission lines in the spectra of these LAEs enables the determination of accurate systemic redshifts and Lyα velocity offsets, as well as the physical and chemical composition of their stars and interstellar media. These faint LAEs are consistent with metal-poor systems with high ionization parameters, similar to the general galaxy population at z > 6. We measured an average ionizing photon production efficiency, log(ξion/erg−1 Hz) ≈ 25.57 across our LAEs, which does not evolve strongly with redshift. We report an anti-correlation between the Lyα escape fraction and the velocity offset from systemic redshift, consistent with model expectations. We further find that the strength and velocity offset of…

X-ray quasi-periodic eruptions (QPEs) are a novel addition to the group of extragalactic transients. With only a select number of known sources, and many more models published trying to explain them, we are so far limited in our understanding by small number statistics. In this work, we report the discovery of two further galaxies showing QPEs, hereafter named eRO-QPE3 and eRO-QPE4, with the eROSITA X-ray telescope on board the Spectrum Roentgen Gamma observatory, followed by XMM-Newton , NICER, Swift -XRT, SALT ( z = 0.024 and z = 0.044, respectively), and ATCA observations. Among the properties in common with those of known QPEs are: the thermal-like spectral shape in eruption (up to kT ∼ 110 − 120 eV) and quiescence ( kT ∼ 50 − 90 eV) and its evolution during the eruptions (with a harder rise than decay); the lack of strong canonical signatures of active nuclei (from current optical, UV, infrared and radio data); and the low-mass nature of the host galaxies (log M * ≈ 9 − 10) and their massive central black holes (log M BH ≈ 5 − 7). These discoveries also bring several new…

We present the results of a search for continuous gravitational wave signals (CGWs) in the second data release (DR2) of the European Pulsar Timing Array (EPTA) Collaboration. The most significant candidate event from this search has a gravitational wave frequency of 4–5 nHz. Such a signal could be generated by a supermassive black hole binary (SMBHB) in the local Universe. We present the results of a follow-up analysis of this candidate using both Bayesian and frequentist methods. The Bayesian analysis gives a Bayes factor of 4 in favour of the presence of the CGW over a common uncorrelated noise process. In contrast, the frequentist analysis estimates the p-value of the candidate to be < 1%, also assuming the presence of common uncorrelated red noise. However, comparing a model that includes both a CGW and a gravitational wave background (GWB) to a GWB only, the Bayes factor in favour of the CGW model is only 0.7. Therefore, we cannot conclusively determine the origin of the observed feature, nor can we rule it out as a CGW source. We present results of simulations that demonstrate…

Context . The study of the chemical composition of the interstellar medium (ISM) requires a strong synergy between laboratory astrophysics, modeling, and observations. In particular, astrochemical models have been developed for decades now and include an increasing number of processes studied in the laboratory or theoretically. These models follow the chemistry both in the gas phase and at the surface of interstellar grains. Since 2012, we have provided complete gas-phase chemical networks for astrochemical codes that can be used to model various environments of the ISM. Aims . Our aim is to introduce the new up-to-date astrochemical network kida.uva.2024 together with the ice chemical network and the fortran code to compute time dependent compositions of the gas, the ice surface, and the ice mantles under physical conditions relevant for the ISM. Methods . The gas-phase chemical reactions, as well as associated rate coefficients, included in kida.uva.2024 were carefully selected from the KIDA online database and represent the most recent values. The model predictions for cold core…

The James Webb Space Telescope (JWST) is revolutionizing our understanding of black hole formation and growth in the early Universe. However, JWST has also revealed that some of the classical diagnostics, such as the Baldwin, Phillips & Terlevich (BPT) diagrams and X-ray emission, often fail to identify active galactic nuclei (AGN) at high redshift and low metallicity. Here we present three new rest-frame optical diagnostic diagrams to identify narrow-line Type II AGN, leveraging the [OIII]λ4363 auroral line, which has been detected in several JWST spectra. Specifically, we show that high values of the [OIII]λ 4363 / Hγ ratio provide a sufficient (but not necessary) condition to identify the presence of an AGN, based on empirical calibrations (using local and high-redshift sources) and on a broad range of photoionization models. These diagnostics are able to separate much of the AGN population from star-forming galaxies (SFGs): the average energy of an AGN’s ionizing photons is higher than that of young stars in SFGs, and hence AGN can more efficiently heat the gas, thus boosting…

The overabundance of super-early (redshiftz > 10) luminous (MUV < −20) blue galaxies detected by JWST has been explained as being due to negligible dust attenuation in these systems. We show that this model correctly reproduces the UV luminosity function atz > 10 and the star formation rate (SFR) density evolution. The model also predicts, in agreement with data, that the cosmic specific SFR (sSFR) grows as sSFR ∝ (1 + z)3/2. Atz ≃ 10, the cosmic sSFR crosses the critical value sSFR⋆ = 25 Gyr−1, and approximately 45% of the galaxies become super-Eddington, driving outflows reaching velocities of ≈830(ϵ⋆/fM)1/2km s−1, whereϵ⋆andfMare the star formation efficiency and fraction of the halo gas expelled in the outflow, respectively. This prediction is consistent with the outflow velocities measured in 12 super-Eddington galaxies of the JWST/JADES sample. Such outflows clear the dust, thus boosting the galaxy luminosity. They also dramatically enhance the visibility of the Lyαline fromz > 10 galaxies by introducing a velocity offset. The observed Lyαproperties in GN-z11 (z = 10.6) are…

The growing number of well-characterized exoplanets smaller than Neptune enables us to conduct more detailed population studies. We have updated the PlanetS catalog of transiting planets with precise and robust mass and radius measurements and use this comprehensive catalog to explore mass-radius ( M–R ) diagrams. On the one hand, we propose new M–R relationships to separate exoplanets into three populations: rocky planets, volatile-rich planets, and giant planets. On the other hand, we explore the transition in radius and density between super-Earths and sub-Neptunes around M-dwarfs and compare them with those orbiting K- and FG-dwarfs. Using Kernel density estimation method with a re-sampling technique, we estimated the normalized density and radius distributions, revealing connections between observations and theories on composition, internal structure, formation, and evolution of these exo-planets orbiting different spectral types. First, the substantial 30% increase in the number of well-characterized exoplanets orbiting M-dwarfs compared with previous studies shows us that…

We report the discovery of a compact star-forming galaxy at z = 9.380 in the GOODS-North field (named GN-z9p4), which shows numerous strong UV-optical emission lines and a single UV line, N IV ] λ 1486. This makes GN-z9p4 the third-highest redshift N-emitter known to date. We determined the nebular abundances of H, C, N, O and Ne, along with the size and other physical properties of this object, then compared them to those of the other N-emitters known so far and to other star-forming galaxies. Using the direct method, we found a metallicity of 12 + log(O/H) = 7.37 ± 0.15, which stands as one of the lowest among N-emitters. The N/O abundance ratio is highly super-solar, while C/O and Ne/O are normal compared to other galaxies at low metallicity. We show that the compactness of GN-z9p4 (with an effective radius of 118 ± 16 pc at 2 μm) and other N-emitters translates to very high stellar mass and star formation rate (SFR) surface densities, which could serve as a criterium for identifying other N-emitters. Future studies and larger samples are needed to understand these rare, and…

Context. The SPT0311–58 system resides in a massive dark-matter halo at z ∼ 6.9. It hosts two dusty galaxies (E and W) with a combined star formation rate (SFR) of ∼3500 M ⊙ yr −1 , mostly obscured and identified by the rest-frame IR emission. The surrounding field exhibits an overdensity of submillimetre sources, making it a candidate protocluster. Aims. Our main goal is to characterise the environment and the properties of the interstellar medium (ISM) within this unique system. Methods. We used spatially resolved low-resolution ( R = 100) and high-resolution ( R = 2700) spectroscopy provided by the JWST/NIRSpec Integral Field Unit to probe a field of ∼17 × 17 kpc 2 around this object, with a spatial resolution of ∼0.5 kpc. Results. These observations reveal ten new galaxies at z ∼ 6.9 characterised by dynamical masses spanning from ∼10 9 to 10 10 M ⊙ and a range in radial velocity of ∼1500 km s −1 , in addition to the already known E and W galaxies. The implied large number density ( ϕ ∼ 10 4 Mpc −3 ) and the wide spread in velocities confirm that SPT0311–58 is at the core of a…

The radius valley separating super-Earths from mini-Neptunes is a fundamental benchmark for theories of planet formation and evolution. Observations show that the location of the radius valley decreases with decreasing stellar mass and with increasing orbital period. Here, we build on our previous pebble-based formation model. Combined with photoevaporation after disc dispersal, it has allowed us to unveil the radius valley as a separator between rocky and water-worlds. In this study, we expand our model for a range of stellar masses spanning from 0.1 to 1.5 M ⊙ . We find that the location of the radius valley is well described by a power-law in stellar mass as R valley = 1.8197 M ⋆ 0.14(+0.02/−0.01) , which is in excellent agreement with observations. We also find very good agreement with the dependence of the radius valley on orbital period, both for FGK and M dwarfs. Additionally, we note that the radius valley gets filled towards low stellar masses, particularly at 0.1–0.4 M ⊙ , yielding a rather flat slope in R valley − P orb . This is the result of orbital migration occurring…

Star formation histories (SFHs) of early galaxies (6 < z < 12) have been found to be highly stochastic in both simulations and observations, while at z ≲6 the presence of a main sequence (MS) of star-forming galaxies implies secular processes at play. In this work we characterise the SFH variability of early galaxies as a function of their stellar mass and redshift. We used the JADES public catalogue and derived the physical properties of the galaxies as well as their SFHs using the spectral energy distribution modelling code CIGALE . To this end, we implemented a non-parametric SFH with a flat prior allowing for as much stochasticity as possible. We used the star formation rate (SFR) gradient, an indicator of the movement of galaxies on the SFR– M * plane, linked to the recent SFH of galaxies. This dynamical approach of the relation between the SFR and stellar mass allows us to show that, at z > 9, 87% of massive galaxies (log( M * / M ⊙ )≳9) have SFR gradients consistent with a stochastic star formation activity during the last 100 Myr, while this fraction drops to 15% at z < 7.…

By using the GRAVITY instrument with the near-infrared (NIR) Very Large Telescope Interferometer (VLTI), the structure of the broad (emission-)line region (BLR) in active galactic nuclei (AGNs) can be spatially resolved, allowing the central black hole (BH) mass to be determined. This work reports new NIR VLTI/GRAVITY interferometric spectra for four type 1 AGNs (Mrk 509, PDS 456, Mrk 1239, and IC 4329A) with resolved broad-line emission. Dynamical modelling of interferometric data constrains the BLR radius and central BH mass measurements for our targets and reveals outflow-dominated BLRs for Mrk 509 and PDS 456. We present an updated radius-luminosity (R-L) relation independent of that derived with reverberation mapping (RM) measurements using all the GRAVITY-observed AGNs. We find our R-L relation to be largely consistent with that derived from RM measurements except at high luminosity, where BLR radii seem to be smaller than predicted. This is consistent with RM-based claims that high Eddington ratio AGNs show consistently smaller BLR sizes. The BH masses of our targets are also…

The first SRG/eROSITA All-Sky Survey (eRASS1) provides the largest intracluster medium-selected galaxy cluster and group catalog covering the western Galactic hemisphere. Compared to samples selected purely on X-ray extent, the sample purity can be enhanced by identifying cluster candidates using optical and near-infrared data from the DESI Legacy Imaging Surveys. Using the red-sequence-based cluster finder eROMaPPer , we measured individual photometric properties (redshift z λ , richness λ , optical center, and BCG position) for 12000 eRASS1 clusters over a sky area of 13 116 deg 2 , augmented by 247 cases identified by matching the candidates with known clusters from the literature. The median redshift of the identified eRASS1 sample is z = 0.31, with 10% of the clusters at z > 0.72. The photometric redshifts have an accuracy of δz /(1 + z ) ≲ 0.005 for 0.05 < z < 0.9. Spectroscopic cluster properties (redshift z spec and velocity dispersion σ ) were measured a posteriori for a subsample of 3210 and 1499 eRASS1 clusters, respectively, using an extensive compilation of…

We present the first homogeneous release of several thousand spectroscopically classified type Ia supernovae (SNe Ia) with spectroscopic redshifts. This release, named “DR2”, contains 3628 nearby ( z < 0.3) SNe Ia discovered, followed, and classified by the Zwicky Transient Facility survey between March 2018 and December 2020. Of these, 3000 have good-to-excellent sampling and 2667 pass standard cosmology light curve quality cuts. This release is thus the largest SN Ia release to date, increasing by an order of magnitude the number of well-characterized low-redshift objects. With DR2, we also provide a volume-limited ( z < 0.06) sample of nearly a thousand SNe Ia. With such a large, homogeneous, and well-controlled dataset, we are studying key current questions on SN cosmology, such as the linearity SNe Ia standardization, the SN and host dependencies, the diversity of the SN Ia population, and the accuracy of current light curve modeling. These, and more, are studied in detail in a series of articles associated with this release. Alongside the SN Ia parameters, we publish our…

Context. The features in the light curves and spectra of many Type I and Type II supernovae (SNe) can be understood by assuming an interaction of the SN ejecta with circumstellar matter (CSM) surrounding the progenitor star. This suggests that many massive stars may undergo various degrees of envelope stripping shortly before exploding, and may therefore produce a considerable diversity in their pre-explosion CSM properties. Aims. We explore a generic set of about 100 detailed massive binary evolution models in order to characterize the amount of envelope stripping and the expected CSM configurations. Methods. Our binary models were computed with the MESA stellar evolution code, considering an initial primary star mass of 12.6 M ⊙ and secondaries with initial masses of between ∼12 M ⊙ and ∼1.3 M ⊙ , and focus on initial orbital periods above ∼500 d. We compute these models up to the time of iron core collapse in the primary. Results. Our models exhibit varying degrees of stripping due to mass transfer, resulting in SN progenitor models ranging from fully stripped helium stars to…

Observations by the James Webb Space Telescope of the Universe at z ≳ 4 have shown that massive black holes (MBHs) appear to be extremely overmassive compared to the local correlation for active galactic nuclei. In some cases, these objects might even reach half the stellar mass inferred for the galaxy. It has become a great challenging for theoretical models to understand how these objects formed and grew to these masses. Different ideas range from heavy seed to super-Eddington accretion phases. We take a different approach and try to infer how accurate these MBH mass estimates are and whether we really need to revise our physical models. By considering how the emerging spectrum (both the continuum and the broad lines) of an accreting MBH changes close to and above the Eddington limit, we infer a much larger uncertainty in the MBH mass estimates relative to that of local counterparts. The uncertainty is up to an order of magnitude. We also infer a potential preference for lower masses and higher accretion rates, which i) moves accreting MBHs closer to the local correlations, and…

Determining the mass–radius ( M − R ) relation of exoplanets is important for exoplanet characterization. Here, we present a re-analysis of the M − R relations and their transitions using exoplanetary data from the PlanetS catalog, which accounts only for planets with reliable mass and radius determination. We find that “small planets” correspond to planets with masses of up to ~4.4 M ⊕ (within 17%) where R ∝ M 0.27 . Planets with masses between ~4.4 and 127 M ⊕ (within 5%) can be viewed as “intermediate-mass” planets, where R ∝ M 0.67 . Massive planets, or gas giant planets, are found to have masses beyond 127 M ⊕ and an M − R relation of R ∝ M −0.06 . By analyzing the radius-density relation we also find that the transition from “small” to “intermediate” planets occurs at a planetary radius of ~1.6 R ⊕ (within 3%). Our results are consistent with previous studies’ results and provide an ideal fit for the current measured planetary population.

We present the latest version of the GAlaxy Evolution and Assembly (GAEA) theoretical model of galaxy formation. Our new model now combines (i) an updated treatment of feedback from active galactic nuclei, including an improved modelling of cold gas accretion on super-massive black holes and an explicit implementation of quasar winds; and (ii) a treatment for both cold and hot gas stripping from satellite galaxies. We show that our latest model version predicts specific star formation rate distributions that are in remarkable agreement with observational measurements in the local Universe. Our updated model predicts quenched fractions that are in very nice agreement with observational measurements up to z ∼ 3 − 4, and a turn-over of the number densities of quenched galaxies at low stellar masses that is in qualitative agreement with current observational estimates. We show that the main reasons for the improved behaviour with respect to previous renditions of our model are the updated treatment for satellites at low galaxy masses (< 1010 M⊙) and the inclusion of quasar winds at…

The Epoch of Reionization (EoR) began when galaxies grew in abundance and luminosity, so their escaping Lyman continuum (LyC) radiation started ionizing the surrounding neutral intergalactic medium (IGM). Despite significant recent progress, the nature and role of cosmic reionizers are still unclear: in order to define them, it would be necessary to directly measure their LyC escape fraction ( f esc ). However, this is impossible during the EoR due to the opacity of the IGM. Consequently, many efforts at low and intermediate redshift have been made to determine measurable indirect indicators in high-redshift galaxies so that their f esc can be predicted. This work presents the analysis of the indirect indicators of 62 spectroscopically confirmed star-forming galaxies at 6 ≤ z ≤ 9 from the Cosmic Evolution Early Release Science (CEERS) survey, combined with 12 sources with public data from other JWST-ERS campaigns. From the NIRCam and NIRSpec observations, we measured their physical and spectroscopic properties. We discovered that on average 6 < z < 9 star-forming galaxies are…

Context. Observations with the James Webb Space Telescope (JWST) have revealed an abundance of bright z > 10 galaxy candidates, challenging the predictions of most theoretical models at high redshifts. Aims. Since massive stars dominate the observable ultraviolet (UV) emission, we explore whether a stellar initial mass function (IMF) that becomes increasingly top-heavy towards higher redshifts and lower gas-phase metallicities results in a higher abundance of bright objects in the early universe and how it influences the evolution of galaxy properties compared to a constant Salpeter IMF. Methods. We parameterised the IMF based on the findings from hydrodynamical simulations that track the formation of stars in differently metal-enriched gas clouds in the presence of the cosmic microwave background (CMB) at different redshifts. We incorporated this evolving IMF into the A STRAEUS (semi-numerical rAdiative tranSfer coupling of galaxy formaTion and Reionisation in N -body dArk mattEr simUlationS) framework, which couples galaxy evolution and reionisation in the first billion years. Our…

The sample of planet-forming disks observed by high-contrast imaging campaigns over the last decade is mature enough to enable the demographical analysis of individual star-forming regions. We present the full census of Taurus sources with VLT/SPHERE polarimetric images available. The whole sample sums up to 43 targets (of which 31 have not been previously published) corresponding to one-fifth of the Class II population in Taurus and about half of such objects that are observable. A large fraction of the sample is apparently made up of isolated faint disks (equally divided between small and large self-shadowed disks). Ambient signal is visible in about one-third of the sample. This probes the interaction with the environment and with companions or the outflow activity of the system. The central portion of the Taurus region almost exclusively hosts faint disks, while the periphery also hosts bright disks interacting with their surroundings. The few bright disks are found around apparently older stars. The overall picture is that the Taurus region is in an early evolutionary stage of…

We present the JWST/NIRSpec PRISM follow-up of candidate galaxies at z ≃ 9–11 selected from deep JWST/NIRCam photometry in GLASS-JWST Early Release Science data. We spectroscopically confirm six sources with secure redshifts at z = 9.52–10.43, each showing multiple emission lines. An additional object is likely at z ≃ 10.66, based on its Ly α -break and a single emission feature, while one source is a lower-redshift interloper. The sample includes the first JWST-detected candidate at z ∼ 10, GHZ1/GLASS-z10, which we confirm at z = 9.875, and the X-ray detected active galactic nucleus (AGN) GHZ9 at z = 10.145. Three objects, including GHZ9, have EW(C III ] λ 1908) > 20 Å and occupy a region compatible with AGN emission in the EW(CIII]) vs CIV/CIII] diagram. The spectroscopic sample confirms a high abundance of galaxies at z > 9. We measure a number density of z ∼ 10 galaxies in the GLASS-JWST ERS field that is a factor of > 3 higher than other JWST-based estimates at demagnified rest-frame magnitudes of −21 ≤ M UV ≤ −19. We find that the positions of these galaxies in redshift and…

The study of gas-phase metallicity and its spatial distribution at high redshift is crucial to understand the processes that shaped the growth and evolution of galaxies in the early Universe. Here we study the spatially resolved metallicity in three systems at z ∼ 6 − 8, namely A2744-YD4, BDF-3299, and COSMOS24108, with JWST NIRSpec IFU low-resolution ( R ∼ 100) spectroscopic observations. These are among the highest- z sources in which metallicity gradients have been probed so far. Each of these systems hosts several spatial components in the process of merging within a few kiloparsecs, identified from the rest-frame UV and optical stellar continuum and ionised gas emission line maps. The sources have heterogeneous properties, with stellar masses log( M * / M ⊙ ) ∼7.6–9.3, star formation rates (SFRs) ∼1–15 M ⊙ yr −1 , and gas-phase metallicities 12+log(O/H) ∼7.7–8.3, which exhibit a large scatter within each system. Their properties are generally consistent with those of the highest-redshift samples to date ( z ∼ 3 − 10), though the sources in A2744-YD4 and COSMOS24108 are at the…

Context. The circumgalactic medium (CGM) provides the material needed for galaxy formation and influences galaxy evolution. The hot ( T > 10 6 K ) CGM is poorly detected around galaxies with stellar masses ( M * ) lower than 3 × 10 11 M ⊙ due to the low surface brightness. Aims. We aim to detect the X-ray emission from the hot CGM around Milky Way-mass (MW-mass, log( M * / M ⊙ ) = 10.5 − 11.0) and M31-mass (log( M * / M ⊙ ) = 11.0 − 11.25) galaxies, in addition to measuring the X-ray surface brightness profile of the hot CGM. Methods. We applied a stacking technique to gain enough statistics to detect the hot CGM. We used the X-ray data from the first four SRG/eROSITA All-Sky Surveys (eRASS:4). We discussed how the satellite galaxies could bias the stacking and the method we used to carefully build the central galaxy samples. Based on the SDSS spectroscopic survey and halo-based group finder algorithm, we selected central galaxies with spectroscopic redshifts of z spec < 0.2 and stellar masses of 10.0 < log( M * / M ⊙ ) < 11.5 (85 222 galaxies) – or halo masses of 11.5 < log( M 200m…

With four companions at separations from 16 to 71 au, HR 8799 is a unique target for direct imaging, presenting an opportunity for a comparative study of exoplanets with a shared formation history. Combining new VLTI/GRAVITY observations obtained within the ExoGRAVITY program with archival data, we performed a systematic atmospheric characterisation across all four planets. We explored different levels of model flexibility to understand the temperature structure, chemistry, and clouds of each planet using both petitRADTRANS atmospheric retrievals and fits to self-consistent radiative–convective equilibrium models. Using Bayesian model averaging to combine multiple retrievals (a total of 89 across all four planets), we find that the HR 8799 planets are highly enriched in metals, with [M/H] ≳1, and have stellar to superstellar atmospheric C/O ratios. The C/O ratio increases with increasing separation from 0.55 −0.10 +0.12 for d to 0.78 −0.04 +0.03 for b, with the exception of the innermost planet, which has a C/O ratio of 0.87 ± 0.03. Such high metallicities are unexpected for these…

Context. Recent observations have positioned the end point of the Epoch of Reionization (EoR) at a redshift of z ∼ 5.3. However, observations of the Lyman-α forest have not yet been able to discern whether reionization occurred slowly and late, with substantial neutral hydrogen persisting at a redshift of ∼6, or rapidly and earlier, with the apparent late end driven by the fluctuating ultraviolet background. Gunn-Peterson (GP) absorption troughs are solid indicators that reionization is not complete until z = 5.3, but whether they contain significantly neutral gas has not yet been proven. Aims. We aim to answer this question by directly measuring, for the first time, the neutral hydrogen fraction (xHI) at the end of the EoR (5 ≲ z ≲ 6) in high-redshift quasar spectra. Methods. For high neutral fractions, xHI ≳ 0.1, GP troughs exhibit damping wing (DW) absorption extending over 1000 km s−1 beyond the troughs. While conclusively detected in Lyman-α emission lines of quasars at z ≥ 7, DWs are challenging to observe in the general Lyman-α forest due to absorption complexities and…

We investigated a possible interaction between cold dark matter and dark energy, corresponding to a well-known interacting dark energy model discussed in the literature within the context of resolving the Hubble tension. We put constraints on it in a novel way, by creating new likelihoods with an analytical marginalization over the Hubble parameterH0, the sound horizonrd, and the supernova absolute magnitudeMB. Our aim is to investigate the impacts on the coupling parameter of the interacting model,ξ, and the equation of state of dark energywand the matter density parameter Ωm, 0. The late-time cosmological probes used in our analysis include the PantheonPlus (calibrated and uncalibrated), cosmic chronometers, and baryon acoustic oscillation samples and the Pantheon for comparison. Through various combinations of these datasets, we demonstrate hints of an up to 2σdeviation from the standard Λ cold dark matter model.

We used the spectro-photometric information of ∼219 million stars from Gaia ’s Data Release 3 (DR3) to calculate synthetic, narrowband, metallicity-sensitive CaHK magnitudes that mimic the observations of the Pristine survey, a survey of photometric metallicities of Milky Way stars that has been mapping more than 6500 deg 2 of the northern sky with the Canada–France–Hawaii Telescope since 2015. These synthetic magnitudes were used for an absolute recalibration of the deeper Pristine photometry and, combined with broadband Gaia information, synthetic and Pristine CaHK magnitudes were used to estimate photometric metallicities over the whole sky. The resulting metallicity catalogue is accurate down to [Fe/H]∼−3.5 and is particularly suited for the exploration of the metalpoor Milky Way ([Fe/H] < −1.0). We make available here the catalogue of synthetic CaHK syn magnitudes for all stars with BP/RP information in Gaia DR3, as well as an associated catalogue of more than ∼30 million photometric metallicities for high signal-to-noise FGK stars. This paper further provides the first public…

Context. Atmospheric and dynamical processes are thought to play a major role in shaping the distribution of close-in exoplanets. A striking feature of such distribution is the Neptunian desert, a dearth of Neptunes on the shortest-period orbits. Aims. We aimed to define the boundaries of the Neptunian desert and study its transition into the savanna, a moderately populated region at larger orbital distances. Our goal was to acquire new insight into the processes that carved out the Neptunian landscape, and to provide the exoplanet community with a framework for conducting studies on planet formation and evolution. Methods. We built a sample of planets and candidates based on the Kepler DR25 catalogue and weighed it according to the transit and detection probabilities. We then used the corrected distribution to study occurrences across the period and period-radius spaces. Results. We delimited the Neptunian desert as the close-in region of the period-radius space with no planets at a 3σ level, and provide the community with simple, ready-to-use approximate boundaries. We identified…

The majority of massive stars are expected to exchange mass or merge with a companion during their lives. This immediately implies that most supernovae (SNe) are from such post-mass-exchange objects. Here, we explore how mass accretion and merging affect the pre-SN structures of stars and their final fates. To this end, we modelled these complex processes by rapid mass accretion onto stars of different evolutionary stages and followed their evolution up to iron core collapse. We used the stellar evolution code M ESA and inferred the outcome of core-collapse using a neutrino-driven SN model. Our models cover initial masses from 11 to 70 M ⊙ and the accreted mass ranges from 10−200% of the initial mass. All models are non-rotating and for solar metallicity. The rapid accretion model offers a systematic way to approach the landscape of mass accretion and stellar mergers. It is naturally limited in scope and serves as a clean zeroth order baseline for these processes. We find that mass accretion, in particular onto post-main-sequence (post-MS) stars, can lead to a long-lived blue…

Context. The source regions of ordinary chondrites (~80% of all falls) and large S-type near-Earth objects (NEOs; ~30%) have recently been identified with three young asteroid families (Karin, Koronis, Massalia) being at the origin of most ordinary chondrite falls. Aims. The present work is a continuation of our previous studies and aims to determine the source regions of the remaining meteorite and NEO classes, with an emphasis on carbonaceous chondrites (CM, CI, CO, CV, CK, CR, CH, CB, or C-ungrouped). Methods. We studied 38 individual asteroid families, including young and old ones, and determined their contributions to the NEO populations at metre and kilometre sizes using collisional and orbital models. Our models are in agreement with spectroscopic observations of NEOs, cosmic-ray exposure ages of meteorites, statistics of bolides, infrared emission from dust bands, composition of interplanetary dust particles (IDPs), and abundance of extraterrestrial helium-3. Results. We identified the Veritas, Polana, and Eos families as the primary sources of CM/CR, CI, and CO/CV/CK…

The resonant scattering interaction between Ly α photons and neutral hydrogen implies that a partially neutral intergalactic medium has the ability to significantly impact the detectability of Ly α emission in galaxies. Thus, the redshift evolution of the Ly α equivalent width distribution of galaxies offers a key observational probe of the degree of ionization during the Epoch of Reionization (EoR). Previous in-depth investigations at z ≥ 7 were limited by ground-based instrument capabilities. We present an extensive study of the evolution of Ly α emission from galaxies at 4.5 < z < 8.5, observed as part of the CEERS and JADES surveys in the JWST NIRSpec/PRISM configuration. The sample consists of 235 galaxies in the redshift range of 4.1 < z < 9.9. We identified 65 of them as Ly α emitters. We first measured the Ly α escape fractions from Ly α to Balmer line flux ratios and explored the correlations with the inferred galaxies’ physical properties, which are similar to those found at lower redshift. We also investigated the possible connection between the escape of Ly α photons and…

We present new measurements of the values of the Hubble constant, matter density, dark energy density, and dark energy density equation-of-state (EoS) parameters. These results have been obtained from a full strong-lensing analysis of the observed positions of 89 multiple images and 4 measured time delays of the supernova (SN) Refsdal in the Hubble Frontier Fields galaxy cluster MACS J1149.5+2223. By strictly following the identical modelling methodology (as done in our previous work undertaken before time delays were available), our cosmographic measurements are essentially blind, based on the frozen procedure. Without using any priors from other cosmological experiments, in an open wCDM cosmological model and via our reference cluster mass model, we measure the following values: H0 = 65.1−3.4+3.5 km s−1 Mpc−1, ΩDE = 0.76−0.10+0.15, and w = −0.92−0.21+0.15 (at the 68.3% confidence level). No other single cosmological probe has been able to simultaneously measure all these parameters. Remarkably, our estimated values of the cosmological parameters, in particular that of H0, are very…

Hierarchical black hole (BH) mergers in active galactic nuclei (AGNs) are unique among formation channels of binary black holes (BBHs) because they are likely associated with electromagnetic counterparts and can efficiently lead to the mass growth of BHs. Here, we explore the impact of gas accretion and migration traps on the evolution of BBHs in AGNs. We have developed a new fast semi-analytic model, that allows us to explore the parameter space while capturing the main physical processes involved. We find that an effective exchange of energy and angular momentum between the BBH and the surrounding gas (i.e., gas hardening) during inspiral greatly enhances the efficiency of hierarchical mergers, leading to the formation of intermediate-mass BHs (up to 104 M⊙) and triggering spin alignment. Moreover, our models with efficient gas hardening show both an anticorrelation between the BBH mass ratio and the effective spin and a correlation between the primary BH mass and the effective spin. In contrast, if gas hardening is inefficient, the hierarchical merger chain is already truncated…

Studying the orbital motion of stars around Sagittarius A* in the Galactic center provides a unique opportunity to probe the gravitational potential near the supermassive black hole at the heart of our Galaxy. Interferometric data obtained with the GRAVITY instrument at the Very Large Telescope Interferometer (VLTI) since 2016 has allowed us to achieve unprecedented precision in tracking the orbits of these stars. GRAVITY data have been key to detecting the in-plane, prograde Schwarzschild precession of the orbit of the star S2 that is predicted by general relativity. By combining astrometric and spectroscopic data from multiple stars, including S2, S29, S38, and S55 – for which we have data around their time of pericenter passage with GRAVITY – we can now strengthen the significance of this detection to an approximately 10 σ confidence level. The prograde precession of S2’s orbit provides valuable insights into the potential presence of an extended mass distribution surrounding Sagittarius A*, which could consist of a dynamically relaxed stellar cusp comprising old stars and…

Recent observations with the James Webb Space Telescope (JWST) have further refined the spectroscopic redshift of GN-z11, one of the most distant galaxies identified with the Hubble Space Telescope, at z = 10.603. The presence of extremely dense gas (> 10 10 cm −3 ), the detection of high-ionisation lines and of CII*1335 emission, and the presence of an ionisation cone indicate that GN-z11 also hosts an active galactic nucleus. Further photometric and spectroscopic follow-up demonstrates that it lies in a large-scale, overdense structure with possible signatures of Population III stars in its halo. Surprisingly, Ly α has also been detected despite the expected largely neutral intergalactic medium at such a redshift. We exploit recent JWST/NIRSpec integral field unit observations to demonstrate that the Ly α emission in GN-z11 is part of an extended halo with a minimum size of 0.8–3.2 kpc, depending on the definition used to derive the halo size. The surface brightness of the Ly α halo around GN-z11 appears consistent with Ly α halos observed around z ∼ 6 quasars. At the wavelength…

Context. Theoretical models struggle to reproduce dynamically cold disks with significant rotation-to-dispersion support (Vrot/σ) observed in star-forming galaxies in the early Universe at redshift z > 4. Aims. We aim to explore the possible emergence of dynamically cold disks in cosmological simulations and to understand whether different kinematic tracers can help reconcile the tension between theory and observations. Methods. We used 3218 galaxies from the SERRA suite of zoom-in simulations, with 8 ≤ log(M⋆/M⊙) ≤ 10.3 and star formation rates SFR ≤ 128 M⊙/yr, within the 4 ≤ z ≤ 9 range. We generated hyperspectral data cubes for 2 × 3218 synthetic observations of Hα and [CII]. Results. We find that the choice of kinematic tracer strongly influences gas velocity dispersion (σ) estimates. In Hα ([C II]) synthetic observations, we observe a strong (mild) correlation between σ and M⋆. This difference mostly arises for M⋆ > 109 M⊙ galaxies, for which σHα > 2σ[CII] for a significant fraction of the sample. Regardless of the tracer, our predictions suggest the existence of massive (M⋆ >…

We present the final data release of the Kilo-Degree Survey (KiDS-DR5), a public European Southern Observatory (ESO) wide-field imaging survey optimised for weak gravitational lensing studies. We combined matched-depth multi-wavelength observations from the VLT Survey Telescope and the VISTA Kilo-degree INfrared Galaxy (VIKING) survey to create a nine-band optical-to-near-infrared survey spanning 1347 deg 2 . The median r -band 5 σ limiting magnitude is 24.8 with median seeing 0.7″. The main survey footprint includes 4 deg 2 of overlap with existing deep spectroscopic surveys. We complemented these data in DR5 with a targeted campaign to secure an additional 23 deg 2 of KiDS- and VIKING-like imaging over a range of additional deep spectroscopic survey fields. From these fields, we extracted a catalogue of 126 085 sources with both spectroscopic and photometric redshift information, which enables the robust calibration of photometric redshifts across the full survey footprint. In comparison to previous releases, DR5 represents a 34% areal extension and includes an i -band…

The MHONGOOSE (MeerKAT H I Observations of Nearby Galactic Objects: Observing Southern Emitters) survey maps the distribution and kinematics of the neutral atomic hydrogen (H I ) gas in and around 30 nearby star-forming spiral and dwarf galaxies to extremely low H I column densities. The H I column density sensitivity (3 σ over 16 km s −1 ) ranges from ∼5 × 10 17 cm −2 at 90″ resolution to ∼4 × 10 19 cm −2 at the highest resolution of 7″. The H I mass sensitivity (3 σ over 50 km s −1 ) is ∼5.5 × 10 5 M ⊙ at a distance of 10 Mpc (the median distance of the sample galaxies). The velocity resolution of the data is 1.4 km s −1 . One of the main science goals of the survey is the detection of cold accreting gas in the outskirts of the sample galaxies. The sample was selected to cover a range in H I masses from 10 7 M ⊙ to almost 10 11 M ⊙ in order to optimally sample possible accretion scenarios and environments. The distance to the sample galaxies ranges from 3 to 23 Mpc. In this paper, we present the sample selection, survey design, and observation and reduction procedures. We compared…

Observations of z ≳ 6 quasars provide information on the early evolution of the most massive black holes (MBHs) and galaxies. Current observations, able to trace both gas and stellar properties, reveal a population of MBHs that is significantly more massive than expected from the local MBH-stellar mass relation. The population lies on, but mostly above, the relation observed in the nearby Universe. This suggests that these objects grew very rapidly. To explain their presence when the Universe was less than 1 Gyr old and to assess the physical conditions for their rapid growth, we explored whether episodes of accretion above the Eddington limit can occur across cosmic epochs. By employing state-of-the-art high-resolution cosmological zoom-in simulations of a z ∼ 7 quasar, where different accretion regimes are included consistently, together with their associated radiative and kinetic feedback, we show that super-Eddington phases can be sustained for relatively long timescales (tens of millions of years). This allows the MBH to rapidly grow by up to three orders of magnitude,…

We present a study of the evolution of cosmic filaments across redshift with an emphasis on some important properties: filament lengths, growth rates, and radial profiles of galaxy densities. Following an observation-driven approach, we built cosmic filament catalogues at z = 0, 1, 2, 3, and 4 from the galaxy distributions of the large hydro-dynamical run of the MilleniumTNG project. We employed the extensively used DisPerSE cosmic web finder code, for which we provide a user-friendly guide, including the details of a physics-driven calibration procedure, with the hope of helping future users. We performed the first statistical measurements of the evolution of connectivity in a large-scale simulation, finding that the connectivity of cosmic nodes (defined as the number of filaments attached) globally decreases from early to late times. The study of cosmic filaments in proper coordinates reveals that filaments grow in length and radial extent, as expected from large-scale structures in an expanding Universe. But the most interesting results arise once the Hubble flow is factored out.…

Context. Number counts of galaxy clusters across redshift are a powerful cosmological probe if a precise and accurate reconstruction of the underlying mass distribution is performed – a challenge called mass calibration. With the advent of wide and deep photometric surveys, weak gravitational lensing (WL) by clusters has become the method of choice for this measurement. Aims. We measured and validated the WL signature in the shape of galaxies observed in the first three years of the Dark Energy Survey (DES Y3) caused by galaxy clusters and groups selected in the first all-sky survey performed by SRG (Spectrum Roentgen Gamma)/eROSITA (eRASS1). These data were then used to determine the scaling between the X-ray photon count rate of the clusters and their halo mass and redshift. Methods. We empirically determined the degree of cluster member contamination in our background source sample. The individual cluster shear profiles were then analyzed with a Bayesian population model that self-consistently accounts for the lens sample selection and contamination and includes marginalization…

Context. Using emission lines from metals, we investigate the three-dimensional distribution of temperature and chemistry in ultra-hot Jupiters. Aims. Existing observations of WASP-121 b have suggested an underabundance of titanium and titanium oxide in its terminator region. In this study, we aim to determine whether this depletion is global by investigating the dayside emission spectrum. Methods. We analyzed eight epochs of high-resolution spectra obtained with the ESPRESSO spectrograph, targeting orbital phases when the dayside is in view. We used a cross-correlation method to search for various atoms, TiO, and VO, and compare the results to models. We constrained the velocities and phase function of the emission signal using a Bayesian framework. Results. We report significant detections of Ca I, V I, Cr I, Mn I, Fe I, Co I, and Ni I, but not Ti or TiO. Models containing titanium are unable to reproduce the data. The detected signals are consistent with the known orbital and systemic velocities and with peak emission originating from the substellar point. Conclusions. We find…

Nitrogen-bearing complex organic molecules have been commonly detected in the gas phase but not yet in interstellar ices. This has led to the long-standing question of whether these molecules form in the gas phase or in ices. The James Webb Space Telescope (JWST) offers the sensitivity, spectral resolution, and wavelength coverage needed to detect them in ices and investigate whether their abundance ratios are similar in gas and ice. We report the first tentative detection of CH 3 CN, C 2 H 5 CN and the simple molecule, N 2 O, based on the CN-stretch band in interstellar ices toward three (HOPS 153, HOPS 370, and IRAS 20126+4104) out of the five protostellar systems observed as part of the Investigating Protostellar Accretion (IPA) GO program with JWST-NIRSpec. We also provide upper limits for the two other sources with smaller luminosities in the sample. We detect OCN − in the ices of all sources with typical CH 3 CN/OCN − ratios of around 1. Ice and gas column density ratios of the nitrogen-bearing species with respect to each other are better matched than those with respect to…

The rest-frame UV recombination emission line Ly α can be powered by ionising photons from young massive stars in star-forming galaxies, but the fact that it can be resonantly scattered by neutral gas complicates its interpretation. For reionisation-era galaxies, a neutral intergalactic medium will scatter Ly α from the line of sight, making Ly α a useful probe of the neutral fraction evolution. Here, we explore Ly α in JWST/NIRSpec spectra from the ongoing JADES programme, which targets hundreds of galaxies in the well-studied GOODS-S and GOODS-N fields. These sources are UV-faint (−20.4 < M UV < −16.4) and thus represent a poorly explored class of galaxy. We fitted the low spectral resolution spectra ( R ∼ 100) of a subset of 84 galaxies in GOODS-S with z spec > 5.6 (as derived with optical lines) with line and continuum models to search for significant line emission. Through exploration of the R100 data, we find evidence for Ly α in 17 sources. This sample allowed us to place observational constraints on the fraction of galaxies with Ly α emission in the redshift range 5.6 < z <…

Context. With the advent of JWST, we are acquiring unprecedented insights into the physical and chemical structure of the inner regions of planet-forming disks where terrestrial planet formation occurs. Very low-mass stars (VLMSs) are known to have a high occurrence of the terrestrial planets orbiting them. Exploring the chemical composition of the gas in these inner disk regions can help us better understand the connection between planet-forming disks and planets. Aims. The MIRI mid-Infrared Disk Survey (MINDS) project is a large JWST guaranteed time program whose aim is to characterise the chemistry and physical state of planet-forming and debris disks. We used the JWST-MIRI/MRS spectrum to investigate the gas and dust composition of the planet-forming disk around the VLMS Sz28 (M5.5, 0.12 M ⊙ ). Methods. We used the dust-fitting tool DuCK to determine the dust continuum and to place constraints on the dust composition and grain sizes. We used 0D slab models to identify and fit the molecular spectral features, which yielded estimates on the temperature, column density, and…

Aims. This paper is focused on the segregation of FGK dwarf and giant stars through narrow-band photometric data using the Spanish Virtual Observatory (SVO) Filter Profile Service and associated photometric tools. Methods. We selected spectra from the MILES, STELIB, and ELODIE stellar libraries, and used SVO photometric tools to derive the synthetic photometry in 15 J-PAS narrow filters, which were especially selected to cover spectral features sensitive to gravity changes. Using machine-learning techniques as the Gaussian mixture model and the support vector machine, we defined several criteria based on J-PAS colours to discriminate between dwarf and giant stars. Results. We selected five colour-colour diagrams that presented the most promising separation between both samples. Our results show an overall accuracy in the studied sample of ~0.97 for FGK stars, although a dependence on the luminosity type and the stellar effective temperature was found. We also defined a colour-temperature relation for dwarf stars with effective temperatures between 4 000 and 7 000 K, which allows one…

Context . The past few years have seen a revolution in the study of circumstellar disks. New instrumentation in the near-infrared and (sub)millimeter regimes have allowed us to routinely spatially resolve disks around young stars of nearby star-forming regions. As a result, we have found that substructures with scales of ~10 au in disks are common. We have also revealed a zoo of different morphologies, sizes, and luminosities that is as complex as the diversity of architectures found in evolved exoplanet systems. Aims . We study disk evolutionary trends as they appear in scattered light observations. Scattered light traces the micron-sized particles at the disk surface that are well coupled to the gas. This means that scattered light observations can be used to trace the distribution of the disk gas and its interaction with embedded perturbers. Methods . We used VLT/SPHERE to observe 20 systems in the Cha I cloud in polarized scattered light in the near-infrared. We combined the scattered light observations with existing literature data on stellar properties and with archival ALMA…

Context. Obtaining reliable distance estimates to gas clouds within the Milky Way is challenging in the absence of certain tracers. The kinematic distance approach has been used as an alternative, and it is derived from the assumption of circular trajectories around the Galactic centre. Consequently, significant errors are expected in regions where gas flow deviates from purely circular motions. Aims. We aim to quantify the systematic errors that arise from the kinematic distance method in the presence of a Galactic potential that is non-axisymmetric. We investigated how these errors differ in certain regions of the Galaxy and how they relate to the underlying dynamics. Methods. We performed 2D isothermal hydrodynamical simulation of the gas disk with the moving-mesh code AREPO, adding the capability of using an external potential provided by the AGAMA library for galactic dynamics. We introduced a new analytic potential of the Milky Way, taking elements from existing models and adjusting parameters to match recent observational constraints. Results. In line with results of previous…

We present an analysis of the JWST NIRCam and MIRI morphological and structural properties of 80 massive (log 10 ( M * [M ⊙ ]) = 11.2 ± 0.1) dusty star-forming galaxies at z = 2.7 −0.7 +1.2 , identified as sub-millimetre galaxies (SMGs) by ALMA, which have been observed as part of the JWST PRIMER project. To compare the structure of these massive, active galaxies to more typical, less actively star-forming galaxies, we defined two comparison samples. The first of 850 field galaxies matched in specific star formation rate and redshift and the second of 80 field galaxies matched in stellar mass. From the visual classification of the SMGs, we have identified 20 ± 5% as candidate late-stage major mergers, a further 40 ± 10% as potential minor mergers, and 40 ± 10% that have comparatively undisturbed disc-like morphologies, with no obvious massive neighbours on ≲20–30 kpc (projected) scales. These rates are comparable to those for the field samples and indicate that the majority of the sub-millimetre-detected galaxies are not late-stage major mergers, but have interaction rates similar…

Context. A rich inventory of complex organic molecules (COMs) has been observed in high abundances in the gas phase toward Class 0 protostars. It has been suggested that these molecules are formed in ices and sublimate in the warm inner envelope close to the protostar. However, only the most abundant COM, methanol (CH3OH), had been firmly detected in ices before the era of the James Webb Space Telescope (JWST). Now, it is possible to detect the interstellar ices of other COMs and constrain their ice column densities quantitatively. Aims. We aim to determine the column densities of several oxygen-bearing COMs (O-COMs) in both gas and ice for two low-mass protostellar sources, NGC 1333 IRAS 2A (hereafter IRAS 2A) and B1-c, as case studies in our JWST Observations of Young proto-Stars (JOYS+) program. By comparing the column density ratios with respect to CH3OH between both phases measured in the same sources, we can probe the evolution of COMs from ice to gas in the early stages of star formation. Methods. The column densities of COMs in gas and ice were derived by fitting the spectra…

Circumbinary disks are found in a variety of astrophysical scenarios, spanning binary star formation to accreting supermassive black hole binaries. Depending on the characteristics of the system, the interaction with a circumbinary disk can either damp or excite the binary’s eccentricity and can also widen or shrink the orbit. To predict the outcome of the long-term disk-binary interaction, we present a new formalism based on the results of recent suites of hydrodynamic simulations, which resolve the complex geometry of the gas in the vicinity of the binary and fully account for the gravitational and accretion forces. We released a python package, spindler , that implements our model. We show that – under the assumed thin disk model with a fixed thickness and viscosity prescription – accretion onto the binary depletes the disk mass before inducing a significant change in the orbital separation or the mass ratio, unless the mass reservoir feeding the disk is comparable to the mass of the binary. This finding implies that, in most scenarios, an interaction with a circumbinary disk is…

Context. The study of the Milky Way is living a golden era thanks to the enormous high-quality datasets delivered by Gaia , and space asteroseismic and ground-based spectroscopic surveys. However, the current major challenge to reconstructing the chronology of the Milky Way is the difficulty to derive precise stellar ages for large samples of stars. The colour–magnitude diagram (CMD) fitting technique offers an alternative to individual age determinations to derive the star formation history (SFH) of complex stellar populations. Aims. Our aim is to obtain a detailed dynamically evolved SFH (deSFH) of the solar neighbourhood, and the age and metallicity distributions that result from it. We define deSFH as the amount of mass transformed into stars, as a function of time and metallicity, in order to account for the population of stars contained in a particular volume. Methods. We present a new package to derive SFHs from CMD fitting tailored to work with Gaia data, called CMDft. Gaia , and we use it to analyse the CMD of the Gaia Catalogue of Nearby Stars (GCNS), which contains a…

While small Neptune-like planets are among the most abundant exoplanets, our understanding of their atmospheric structure and dynamics remains sparse. In particular, many unknowns remain regarding the way moist convection works in these atmospheres, where condensable species are heavier than the non-condensable background gas. While it has been predicted that moist convection could cease above some threshold abundance of these condensable species, this prediction is based on simple linear analysis and relies on some strong assumptions regarding the saturation of the atmosphere. To investigate this issue, we developed a 3D cloud-resolving model for hydrogen-dominated atmospheres with large amounts of condensable species and applied it to a prototypical temperate Neptune-like planet – K2-18 b. Our model confirms the inhibition of moist convection above a critical abundance of condensable vapor and the onset of a stably stratified layer in the atmosphere of such planets, which leads to much hotter deep atmospheres and interiors. Our 3D simulations further provide quantitative estimates…

Context . Recent observational constraints in emission, extinction, and polarisation have at least partially invalidated most of the astronomical standard grain models for the diffuse interstellar medium. Moreover, laboratory measurements on interstellar silicate analogues have shown quite significant differences with the optical properties used in these standard models. Aims . To address these issues, our objective is twofold: (i) to update the optical properties of silicates and (ii) to develop The Heterogeneous dust Evolution Model for Interstellar Solids (THEMIS) to allow the calculation of polarised extinction and emission. Methods . Based on optical constants measured in the laboratory from 5 µm to 1 mm for amorphous silicates and on observational constraints in mid-IR extinction and X-ray scattering, we defined new optical constants for the THEMIS silicates. Absorption and scattering efficiencies for spheroidal grains using these properties were subsequently derived with the discrete dipole approximation. Results . These new optical properties make it possible to explain the…

Context . Planetesimal belts are ubiquitous around nearby stars, and their spatial properties hold crucial information for planetesimal and planet formation models. Aims . We present resolved dust observations of 74 planetary systems as part of the REsolved ALMA and SMA Observations of Nearby Stars (REASONS) survey and archival reanalysis. Methods . We uniformly modelled interferometric visibilities for the entire sample to obtain the basic spatial properties of each belt, and combined these with constraints from multi-wavelength photometry. Results . We report key findings from a first exploration of this legacy dataset: (1) Belt dust masses are depleted over time in a radially dependent way, with dust being depleted faster in smaller belts, as predicted by collisional evolution. (2) Most belts are broad discs rather than narrow rings, with much broader fractional widths than rings in protoplanetary discs. We link broad belts to either unresolved substructure or broad planetesimal discs produced if protoplanetary rings migrate. (3) The vertical aspect ratios ( h = H / R ) of 24…

Context. Sulfur is depleted with respect to its cosmic standard abundance in dense star-forming regions. It has been suggested that this depletion is caused by the freeze-out of sulfur on interstellar dust grains, but the observed abundances and upper limits of sulfur-bearing ices remain too low to account for all of the missing sulfur. Toward the same environments, a strong absorption feature at ~6.85 µm is observed, but its long-standing assignment to the NH4+ cation remains tentative. Aims. We aim to spectroscopically investigate the plausibility of NH4SH salt serving as a sulfur reservoir and a carrier of the 6.85 µm band in interstellar ices by characterizing its IR signatures and apparent band strengths in water-rich laboratory ice mixtures. We then use this laboratory data to constrain NH4SH abundances in observations of interstellar ices. Methods. Laboratory transmission IR spectra of NH3:H2S ice mixtures both with and without H2O were collected. The apparent band strengths of the NH4+ asymmetric bending (ν4) mode and the SH− stretching mode in H2O-containing mixtures were…

Aims . We present a set of photometric catalogues primarily aimed at providing the community with a comprehensive database for the study of galaxy populations in the high-redshift Universe. The set gathers data from eight JWST NIRCam observational programs, targeting the Abell 2744 (GLASS-JWST, UNCOVER, DDT2756, and GO3990), EGS (CEERS), COSMOS and UDS (PRIMER), and the GOODS North and South (JADES and NGDEEP) deep fields. This dataset covers a total area of ≃0.2 sq. degrees. Methods . We obtained photometric estimates by means of well-established techniques, including tailored improvements designed to enhance the performance on the specific dataset. We also included new measurements from HST archival data, spanning 16 bands from 0.44 to 4.44 µm. Results . A grand total of ~530 thousand sources were detected on stacks of NIRCam 3.56 and 4.44 µm mosaics. We assessed the photometric accuracy by comparing fluxes and colours against archival catalogues. We also provide photometric redshift estimates, statistically validated against a large set of robust spectroscopic data. Conclusions .…

Aims. This paper utilises the James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) to extend the observational studies of dust and polycyclic aromatic hydrocarbon (PAH) emission to a new mass and star formation rate (SFR) parameter space beyond our local Universe. The combination of fully sampled spectral energy distributions (SEDs) with multiple mid-infrared (mid-IR) bands and the unprecedented sensitivity of MIRI allows us to investigate dust obscuration and PAH behaviour from z = 0.7 up to z = 2 in typical main-sequence galaxies. Our focus is on constraining the evolution of PAH strength and the dust-obscured luminosity fraction before and during cosmic noon, the epoch of peak star formation activity in the Universe. Methods. In this study, we utilise MIRI multi-band imaging data from the SMILES survey (5 to 25 μm), complemented with NIRCam photometry from the JADES survey (1 to 5 μm), available HST photometry (0.4 to 0.9 μm), and spectroscopic redshifts from the FRESCO and JADES surveys in GOODS-S for 443 star-forming (without dominant active galactic nucleus (AGN))…

We report observational evidence of highly turbulent ionized gas kinematics in a sample of 20 Lyman continuum (LyC) emitters (LCEs) at low redshift ( z ∼ 0.3). Detailed Gaussian modeling of optical emission line profiles in high-dispersion spectra consistently shows that both bright recombination and collisionally excited lines can be fitted as one or two narrow components with intrinsic velocity dispersion of σ ∼ 40 − 100 km s −1 , in addition to a broader component with σ ∼ 100 − 300 km s −1 , which contributes up to ∼40% of the total flux and is preferentially blueshifted from the systemic velocity. We interpret the narrow emission as highly ionized gas close to the young massive star clusters and the broader emission as a signpost of unresolved ionized outflows, resulting from massive stars and supernova feedback. We find a significant correlation between the width of the broad emission and the LyC escape fraction, with strong LCEs exhibiting more complex and broader line profiles than galaxies with weaker or undetected LyC emission. We provide new observational evidence…

Eccentric mergers are a signature of the dynamical formation channel of binary black holes (BBHs) in dense stellar environments and hierarchical triple systems. Here, we investigate the formation of eccentric mergers via binary-single interactions by means of 2.5 × 105 direct N-body simulations. Our simulations include post-Newtonian terms up to the 2.5th order and model the typical environment of young (YSCs), globular (GCs), and nuclear star clusters (NSCs). Around 0.6% (1%) of our mergers in NSCs (GCs) have an eccentricity > 0.1 when the emitted gravitational wave frequency is 10 Hz in the source frame, while in YSCs this fraction rises to 1.6%. Approximately ∼63% of these mergers are produced by chaotic, resonant interactions where temporary binaries are continuously formed and destroyed, while ∼31% arise from an almost direct collision of two black holes (BHs). Lastly, ∼6% of these eccentric mergers occur in temporary hierarchical triples. We find that binaries undergoing a flyby generally develop smaller tilt angles with respect to exchanges. This result challenges the idea…

Measurements of the obliquities in exoplanet systems have revealed some remarkable architectures, some of which are very different from the Solar System. Nearly 200 obliquity measurements have been obtained through observations of the Rossiter–McLaughlin (RM) effect. Here, we report on observations of 19 planetary systems that led to 17 clear detections of the RM effect and 2 less secure detections. After adding the new measurements to the tally, we used the entire collection of RM measurements to investigate four issues that have arisen in the literature. i) Does the obliquity distribution show a peak at approximately 90°? We find tentative evidence that such a peak does exist when restricting attention to the sample of sub-Saturn planets and hot Jupiters orbiting F stars. ii) Are high obliquities associated with high eccentricities? We find the association to be weaker than previously reported, and that a stronger association exists between obliquity and orbital separation, possibly due to tidal obliquity damping at small separations. iii) How low are the lowest known obliquities?…

The ionisation cones of NGC 5728 have a deficit of molecular gas based on millimetre observations of CO (2-1) emission. Although photoionisation from the active nucleus may lead to suppression of this transition, warm molecular gas can still be present. We report the detection of eight mid-infrared rotational H 2 lines throughout the central kiloparsec, including the ionisation cones, using integral field spectroscopic observations with JWST/MIRI MRS. The H 2 line ratios, characteristic of a power-law temperature distribution, indicate that the gas is warmest where it enters the ionisation cone through disk rotation, suggestive of shock excitation. In the nucleus, where the data can be combined with an additional seven ro-vibrational H 2 transitions, we find that moderate velocity (30 km s −1 ) shocks in dense (10 5 cm −3 ) gas, irradiated by an external UV field ( G 0 = 10 3 ), do provide a good match to the full set. The warm molecular gas in the ionisation cone that is traced by the H 2 rotational lines has been heated to temperatures > 200 K. Outside of the ionisation cone the…

This study analyses JWST MIRI/MRS observations of the infrared (IR) polycyclic aromatic hydrocarbon (PAH) bands in the nuclear (∼0.4″ at 11 μm; ∼75 pc) and circumnuclear regions (inner ∼kpc) of local active galactic nuclei (AGNs) from the Galactic Activity, Torus, and Outflow Survey (GATOS). We examine the PAH properties in the circumnuclear regions of AGNs and the projected direction of AGN-outflows and compare them to those in star-forming regions and the innermost regions of AGNs. This study employs 4.9–28.1 μm sub-arcsecond angular resolution data to investigate the properties of PAHs in three nearby sources (D L ∼ 30 − 40 Mpc). Our findings are aligned with previous JWST studies, demonstrating that the central regions of AGNs display a larger fraction of neutral PAH molecules (i.e. elevated 11.3/6.2 and 11.3/7.7 μm PAH ratios) in comparison to star-forming galaxies. We find that AGNs might affect not only the PAH population in the innermost region, but also in the extended regions up to ∼kpc scales. By comparing our observations to PAH diagnostic diagrams, we find that, in…

We report the detection of a population of Wolf-Rayet (WR) stars in the Sunburst Arc, a strongly gravitationally lensed galaxy at redshift z = 2.37. As the brightest known lensed galaxy, the Sunburst Arc has become an important cosmic laboratory for studying star and cluster formation, Lyman α (Ly α ) radiative transfer, and Lyman continuum (LyC) escape. Here, we present the first results of JWST/NIRSpec IFU observations of the Sunburst Arc, focusing on a stacked spectrum of the 12-fold imaged Sunburst LyC-emitting (LCE) cluster. In agreement with previous studies, we find that the Sunburst LCE cluster is a very massive, compact star cluster with M dyn = (9 ± 1)×10 6 M ⊙ . Our age estimate of 4.2–4.5 Myr is much larger than the crossing time of t cross = 183 ± 9 kyr, indicating that the cluster is dynamically evolved and consistent with it being gravitationally bound. We find a significant nitrogen enhancement of the low ionization state interstellar medium (ISM), with log(N/O) = − 0.74 ± 0.09, which is ≈0.8 dex above typical values for H II regions of a similar metallicity in the…

Context . The nature of the close-in rocky planet 55 Cnce is puzzling, despite it having been observed extensively. Its optical and infrared occultation depths show temporal variability, in addition to a phase curve variability observed in the optical. Aims . We wish to explore the possibility that the variability originates from the planet being in a 3:2 spin–orbit resonance, and thus showing different sides during occultations. We proposed and were awarded Cycle 1 time at the James Webb Space Telescope (JWST) to test this hypothesis. Methods . JWST/NIRCam (Near Infrared Camera) observed five occultations (secondary eclipses) of the planet – of which four were observed within a week – simultaneously at 2.1 and 4.5 µm. While the former gives band-integrated photometry, the latter provides a spectrum between 3.9–5.0 µm. Results . We find that the occultation depths in both bandpasses are highly variable and change between a non-detection (−5 ± 6 ppm and 7 ± 9 ppm) to 96 ± 8 ppm and 119 −19 +34 ppm at 2.1 µm and 4.5 µm, respectively. Interestingly, the variations in both bandpasses…

Context. In recent years, the gas kinematics probed by molecular lines detected with ALMA has opened a new window into the of study protoplanetary disks. High spatial and spectral resolution observations have revealed the complexity of protoplanetary disk structure. Drawing accurate interpretations of these data allows us to better comprehend planet formation. Aims. We investigate the impact of thermal stratification on the azimuthal velocity of protoplanetary disks. High-resolution gas observations reveal velocity differences between CO isotopologues, which cannot be adequately explained with vertically isothermal models. The aim of this work is to determine whether a stratified model can explain this discrepancy. Methods. We analytically solved the hydrostatic equilibrium for a stratified disk and we derived the azimuthal velocity. We tested the model with SPH numerical simulations and then we used it to fit for the star mass, disk mass, and scale radius of the sources in the MAPS sample. In particular, we used 12CO and 13CO datacubes. Results. When thermal stratification is taken…

Context . Low-mass X-ray binaries (LMXBs) are high-energy sources that require multi-wavelength follow-up campaigns to be fully characterised. New transients associated with LMXBs are regularly discovered, and previously known systems are often revisited by astronomers to constrain their intrinsic parameters. All of this information compiled into a catalogue may build a useful tool for subsequent studies on LMXBs and their population. Aims . We aim to provide an update on past LMXB catalogues dating back 16 yr and propose to the community a database on Galactic LMXBs with the most complete, manually curated set of parameters and their original references. On top of a fixed version accessible through Vizier, we propose hosting the catalogue independently on our GitHub collaboration, side-by-side with our previous catalogue on high-mass X-ray binaries. The database will be regularly updated based on new publications and community inputs. Methods . We built a working base by cross-matching previous LMXB catalogues and supplementing them with lists of hard X-ray sources detected over…

Context. The first eROSITA all-sky survey (eRASS1) performed on board the Spectrum-Roentgen-Gamma mission (SRG) provides more than 900 000 X-ray sources in the 0.2–2.3 keV band located in the western hemisphere. Aims. We present identifications of the eRASS1 sources obtained using our HamStar method, which was designed for the identification of coronal X-ray sources. Methods. HamStar is a Bayesian framework that estimates coronal probabilities for each eRASS1 source based on a cross-match with optical counterparts from Gaia DR3. It considers geometric properties, such as angular separation and positional uncertainty, as well the additional properties of fractional X-ray flux, color, and distance. Results. We identify 138 800 coronal eRASS1 sources and estimate a completeness and reliability of about 91.5% for this sample, which we confirmed with Chandra detections. This is the largest available sample of coronal X-ray emitters and we find nearly five times as many coronal sources as in the ROSAT all-sky survey. The coronal eRASS1 sources are made up of all spectral types and the…

Dust-obscured galaxies are thought to represent an early evolutionary phase of massive galaxies in which the active galactic nucleus (AGN) is still deeply buried in significant amounts of dusty material and its emission is strongly suppressed. The unprecedented sensitivity of the James Webb Space Telescope (JWST) enabled us for the first time to detect the rest-frame optical emission of heavily obscured AGNs and unveil the properties of the hidden accreting super-massive black holes (BHs). In this work, we present the JWST/NIRSpec integral field spectroscopy (IFS) data of ALESS073.1, a massive (log( M ⋆ / M ⊙ ) = 10.98) dusty, star-forming galaxy at z = 4.755 hosting an AGN at its center. The detection of a very broad (> 9000 km s −1 ) H α emission associated with the broad line region (BLR) confirms the presence of a BH (log( M BH / M ⊙ ) > 8.7) accreting at less than 18% of its Eddington limit. The identification of the BLR classifies the target as a type 1 AGN despite the observed high column density of N H ∼ 10 24 cm −2 . The rest-frame optical emission lines also reveal a fast…

Context. Feedback from stars in the form of radiation, stellar winds, and supernovae is crucial to regulating the star formation activity of galaxies. Dwarf galaxies are especially susceptible to these processes, making them an ideal test bed for studying the effects of stellar feedback in detail. Recent numerical models have aimed to resolve the interstellar medium (ISM) in dwarf galaxies with a very high resolution of several solar masses. However, when it comes to modeling the radiative feedback from stars, many models opt for simplified approaches instead of explicitly solving radiative transfer (RT) because of the computational complexity involved. Aims. We introduce the Realistic ISM modeling in Galaxy Evolution and Lifecycles (RIGEL) model, a novel framework to self-consistently model the effects of stellar feedback in the multiphase ISM of dwarf galaxies with explicit RT on a star-by-star basis. Methods. The RIGEL model integrates detailed implementations of feedback from individual massive stars into the state-of-the-art radiation-hydrodynamics code, AREPO-RT. It forms…

Context. The ESO public survey VISTA Variables in the Vía Láctea (VVV) surveyed the inner Galactic bulge and the adjacent southern Galactic disk from 2009–2015. Upon its conclusion, the complementary VVV extended (VVVX) survey has expanded both the temporal as well as spatial coverage of the original VVV area, widening it from 562 to 1700 sq. deg., as well as providing additional epochs in JHK s filters from 2016–2023. Aims. With the completion of VVVX observations during the first semester of 2023, we present here the observing strategy, a description of data quality and access, and the legacy of VVVX. Methods. VVVX took ~2000 h, covering about 4% of the sky in the bulge and southern disk. VVVX covered most of the gaps left between the VVV and the VISTA Hemisphere Survey (VHS) areas and extended the VVV time baseline in the obscured regions affected by high extinction and hence hidden from optical observations. Results. VVVX provides a deep JHK s catalogue of ≳1.5 × 10 9 point sources, as well as a K s band catalogue of ~10 7 variable sources. Within the existing VVV area, we…