Galaxy formation and evolution

Abstract:

We present radial profiles of surface brightness in UV and IR bands, estimate stellar mass surface density (Σ⋆) and star formation rate surface density (ΣSFR), and predict the CO-to-H2 conversion factor (αCO) for over 5000 local galaxies with stellar mass M⋆ ≥ 109.3 M⊙. We build these profiles and measure galaxy half-light radii using GALEX and WISE images from the z0MGS program, with special care given to highly inclined galaxies. From the UV and IR surface brightness profiles, we estimate Σ⋆ and ΣSFR and use them to predict αCO with state-of-the-art empirical prescriptions. We validate our (kpc-scale) αCO predictions against observational estimates, finding the best agreement when accounting for CO-dark gas as well as CO emissivity and excitation effects. The CO-dark correction plays a primary role in lower-mass galaxies, whereas CO emissivity and excitation effects become more important in higher-mass and more actively star-forming galaxies, respectively. We compare our estimated αCO to observed galaxy-integrated SFR to CO luminosity ratio as a function of M⋆. A large compilation of literature data suggests that star-forming galaxies with M⋆ = 109.5–11 M⊙ show strong anticorrelations of SFR/ L′CO(1–0)∝M⋆−0.29 and SFR/ L′CO(2–1)∝M⋆−0.40 . The estimated αCO trends, when combined with a constant molecular gas depletion time tdep, can only explain ≈1/3 of these SFR/ L′CO trends. This suggests that tdep being systematically shorter in lower-mass star-forming galaxies is the main cause of the observed SFR/ L′CO variations. We publish all data products from this work, including galaxy sizes, UV and IR surface brightness profiles, Σ⋆, ΣSFR, and αCO estimates.

Abstract:

We summarize the properties and initial data release of the JADES Origins Field (JOF), the longest single pointing yet imaged with the James Webb Space Telescope (JWST). This field falls within the GOODS-S region about 8′ southwest of the Hubble Ultra Deep Field (HUDF), where it was formed initially in Cycle 1 as a parallel field of HUDF spectroscopic observations within the JWST Advanced Deep Extragalactic Survey (JADES). This imaging was greatly extended in Cycle 2 program 3215, which observed the JOF for 5 days in six medium-band filters, seeking robust candidates for z > 15 galaxies. This program also includes ultradeep parallel NIRSpec spectroscopy (up to 91 hr on source, summing over the dispersion modes) on the HUDF. Cycle 3 observations from program 4540 added 20 hr of NIRCam slitless spectroscopy and F070W imaging to the JOF. With these three campaigns, the JOF was observed for 380 open-shutter hours with NIRCam using 15 imaging filters and two grism bandpasses. Further, parts of the JOF have deep 43 hr MIRI observations in F770W. Taken together, the JOF is one of the most compelling deep fields available with JWST and a powerful window into the early Universe. This paper presents the second data release from JADES, featuring the imaging and catalogs from the year 1 JOF observations.

Abstract:

Context. Jets from accreting black-hole (BH) X-ray binary (XRB) systems are powerful outflows that release a large fraction of the accretion energy to the surrounding environment, providing a feedback mechanism that may alter the properties of the interstellar medium (ISM). Studying accretion processes alongside their feedback on the environment may enable one to estimate the matter and energy input and output around accreting BHs. Aims. We aim to study the extended jet structures around the BH XRB GRS 1758–258. First observed in VLA data, these parsec-scale jet structures originate from jet-ISM interaction, and are characterised by a peculiar Z-shape morphology. Methods. Using the MeerKAT radio telescope we observed GRS 1758–258 in the L band for a total exposure of 7 hr. Following a calorimetry-based method originally proposed for active galactic nuclei (AGN) and later applied to X-ray binaries, we estimated the properties of the jets and of the surrounding ISM. Results. We detect a jet and a counter-jet terminating in bow-shock structures induced by their interaction with the ISM. We identified both synchrotron and bremsstrahlung emitting regions within the northern lobe, while the southern lobe is dominated by thermal emission. We measured an ISM particle density of between 10 and 40 cm −3 across both the northern and southern jets, slightly lower in the northern region. The estimated ages of the two jet sides range from 6 to 51 kyr, with the northern jet seemingly younger than the southern one. The time-averaged transferred jet energy for both jets falls between 4.4 × 10 33 and 3.3 × 10 36 erg s −1 , with slight differences between the northern and southern jets ascribed to different local environmental conditions. Comparing the new MeerKAT with archival VLA observations, we measured a proper motion of a portion of the northern jet of ∼130 mas/year. Conclusions. Jet-ISM interaction structures on both sides of GRS 1758–258 reveal different local ISM properties. The comparison between the morphology of these structures and those from other XRBs indicates that the lobes in GRS 1758–258 may be younger and may result from a number of jet activity phases. The estimated time-averaged energy transferred to the environment is slightly lower than, but comparable to, that observed in other XRBs, consistent with the younger age of the lobes in GRS 1758–258 relative to those of other systems.

Abstract:

Context. The H I mass function (HIMF) is a crucial tool for understanding the evolution of the H I content in galaxies over cosmic time and, hence, to constraining both the baryon cycle in galaxy evolution and the reionization history of the Universe. Aims. We aim to derive semiempirical constraints at z ∼ 0.37 by combining literature results on the stellar mass function from optical surveys with recent findings on the M HI − M ⋆ scaling relation derived via spectral stacking analysis applied to 21 cm line interferometric data from the MIGHTEE and CHILES surveys, conducted with the MeerKAT and VLA radio telescopes, respectively. Methods. We drew synthetic stellar mass samples directly from the publicly available results underlying the analysis of the COSMOS2020 galaxy photometric sample. We then converted M ⋆ into M HI using analytical fitting functions to the data points from H I stacking. We next fit a Schechter function to the median HIMF from all the samples via Monte Carlo Markov chains. We finally derived the posterior distribution for Ω HI by integrating the models for the HIMF built from the posteriors samples of the Schechter parameters. Results. We find a deviation of the HIMF at z ∼ 0.37 from the results at z ∼ 0 from the ALFALFA survey and at z ∼ 1 from uGMRT data. Our results for Ω HI are in broad agreement with other literature results and follow the overall trend on Ω HI as a function of redshift. The derived value Ω HI = (7.02 +0.59 −0.52 ) × 10 −4 at z ∼ 0.37 from the combined analysis deviates by ∼2.9 σ from the ALFALFA result at z ∼ 0. Conclusions. Our findings regarding the HIMF and Ω HI derived from deep, state-of-the-art interferometric surveys differ from previous literature results at z ∼ 0 and z ∼ 1. We are unable to confirm at this stage whether these differences are due to cosmic evolution consistent with a smooth transition of the H I content of galaxies over the last 8 Gyr or due to selection biases and systematics.