We present and investigate the properties of a sample of radio-selected, Euclid-dark galaxies, identified from LOFAR HBA observations at 144 MHz within the Euclid Deep Field-North (EDF-N). Starting from radio sources lacking optical counterparts in previous surveys, but detected with Spitzer/IRAC, we identified 166 galaxies with no emission at a more than 3σ level in Euclid Quick Release 1 (Q1) images, and no matches in the Euclid Q1 catalogue. To minimise contamination from nearby sources, we selected a sub-sample of 88 isolated galaxies. By exploiting multi-band images and catalogues available for the EDF-N, we inferred the physical properties of our sample via SED fitting. The resulting redshift distribution spans 0.4 ≤ z_ph≤ 5.0. We used recent sub-arcsecond imaging from the International LOFAR Telescope to constrain the nature of the compact radio emission through brightness temperature estimates. By combining this information with the radio excess relative to the infrared/radio correlation (IRRC), we searched for possible active galactic nuclei (AGN) activity. Approximately 40

Context. The James Webb Space Telescope (JWST) is revolutionizing our understanding of the Universe by unveiling faint, near-infrared dropouts previously beyond our reach, ranging from exceptionally dusty sources to galaxies up to redshift z ∼ 14. Aims. In this paper, we identify F200W-dropout objects in the Cosmic Evolution Early Release Science (CEERS) survey that are absent from existing catalogs. Our selection method can effectively identify obscured low-mass (logM*/M⊙ ≤ 9) objects at z ≤ 6, massive dust-rich sources up to z ∼ 12, and ultrahigh-redshift (z > 15) candidates. Our goal is to uncover promising targets for further studies using deep mid-infrared imaging and/or spectroscopic follow-ups. Methods. We utilize two photometric catalogs optimized for detecting faint, red objects. Primarily relying on NIRCam photometry from the latest CEERS data release and supplementing with mid-infrared/(sub)millimeter data when available, our analysis pipeline combines multiple SED-fitting codes, star formation histories, and the novel CosMix tool for astronomical stacking to maximize available photometric information. Results. Our work highlights three 2 < z < 3 dusty dwarf galaxies that have higher masses compared to the typical dusty dwarfs previously identified in CEERS. Additionally, we reveal five faint sources with a significant probability of lying above z > 15, with best-fit masses compatible with Λ cold dark matter and a standard baryon-to-star conversion efficiency. We exploit these candidates to compute the z ∼ 17 UV luminosity function, finding estimates in good agreement with other similar studies. Their bimodal redshift probability distributions suggest they could also be z < 1.5 dwarf galaxies with extreme dust extinction. We also identify a strong line emitter galaxy at z ∼ 5 mimicking the near-infrared emission of a z ∼ 13 galaxy. Conclusions. Our sample holds promising candidates for future follow-ups. Confirming ultrahigh-redshift galaxies or lower-redshift dusty dwarfs will offer valuable insights into early galaxy formation, evolution with their central black holes and the nature of dark matter, and/or cosmic dust production mechanisms in low-mass galaxies, and will help us to understand degeneracies and contamination in high-redshift object searches.

Context. The James Webb Space Telescope (JWST) has uncovered a diverse population of extreme near-infrared dropouts, including ultra-high-redshift (z > 15) galaxy candidates, dust-obscured galaxies challenging theories of dust production, sources with strong Balmer breaks (possibly compact active galactic nuclei in dense gas-rich environments), and cold, substellar Galactic objects. Aims. This work presents Capotauro, a F356W-dropout identified in the CEERS survey with a F444W AB magnitude of ∼27.68 and exhibiting a sharp flux drop by > 3 mag between 3.5 and 4.5 μm, being nondetected below 3.5 μm. We investigated its nature and constrained its properties, paving the way for follow-up observations. Methods. We combined JWST/NIRCam, MIRI, and NIRSpec/MSA data with HST/ACS and WFC3 observations to perform a spectrophotometric analysis of Capotauro using multiple SED-fitting codes. Our setup is tailored to test z ≥ 15 as well as z < 10 dusty, Balmer-break or strong-line emitter galaxy solutions, and the possibility of Capotauro being a Milky Way substellar object. Results. Among extragalactic options, our analysis favors interpreting the sharp flux drop of Capotauro as a bright (MUV ∼ −21.5) Lyman break at z ∼ 32, consistent with the formation epoch of the first stars and black holes, with only ∼0.5% of the redshift posterior volume lying at z < 25. Lower-redshift solutions struggle to reproduce the extreme break, suggesting that if Capotauro resides at z < 10, it must show a nonstandard combination of high dust attenuation and/or prominent Balmer breaks, making it a peculiar interloper. Finally, our analysis indicates that Capotauro’s properties could be consistent with it being a very cold (i.e., Y2-Y3 type) brown dwarf or a free-floating exoplanet with a record-breaking combination of low temperature and large distance (Teff ≤ 300 K; d ≳ 130 pc, up to ∼2 kpc). Conclusions. While present observations cannot determine Capotauro’s nature, our analysis points to a remarkably unique object in all plausible scenarios. This makes Capotauro stand out as a compelling target for follow-up observations.

A major unknown in late-stage galaxy evolution is what regulates the cold interstellar medium (ISM) after quenching, a question central to interpreting molecular gas, dust, and stellar content in quiescent galaxies (QGs) now probed by ALMA and JWST to z∼7. We present the first semi-analytic model that follows the coupled post-quenching evolution of dust, cold gas, and polycyclic aromatic hydrocarbons (PAHs), using flexible star-formation histories and a framework tracking small and large carbonaceous and silicate grains. At z∼1, we find that QGs of similar mass (M_⋆∼8×10^10 M_⊙), stellar-population age (∼2 Gyr), and cold gas fractions (f_ gas∼1-10%), span 2-3 dex in M_ dust/M_⋆ and M_ dust/M_ gas, ranging from star-forming-like ratios to highly depleted dust states. The diversity arises from delayed dust injection by thermally pulsing asymptotic giant branch (TP-AGB) stars and ISM grain growth, which sustain dust enrichment for up to ∼2.5 Gyr after quenching. Without these channels, the pre-quenching M_ dust falls below 10% of its initial value within ≲0.5-1 Gyr, and twice as fast when AGN feedback is active. The imprint of post-quenching dust processing persists in substantial reservoirs of small carbonaceous grains, with PAH fractions of ∼2-3%, even if the cold-dust budget falls below typical ALMA continuum detection limits (M_ dust/M_⋆≲10^-4). Such signatures may remain detectable with JWST/MIRI at μJy depths, probing chemically enriched dust phases in otherwise ALMA-faint galaxies. Altogether, dust and PAHs provide independent probes of distinct stages of ISM evolution in QGs, rather than simply tracing the residual cold ISM of the preceding star-forming phase.

Star-forming galaxies (SFGs) dominate the faint radio sky at flux densities below 0.1 mJy. Identifying these systems through a multiwavelength approach is essential to tracing the cosmic history of star formation. Upcoming surveys with the Square Kilometre Array Observatory (SKAO) in its AA4 configuration for the Mid array will probe these faint populations, offering unprecedented insights into the star formation activity of galaxies across cosmic time. Semi-empirical models, built on minimal assumptions and empirical galaxy relations, provide an efficient framework to study galaxy evolution using recent radio and optical/near-infrared (NIR) data. We developed SEMPER (Semi-EMPirical model for Extragalactic Radio emission) to predict the radio luminosity functions and number counts of SFGs. SEMPER combines redshift-dependent stellar mass functions from deep NIR surveys with empirical relations such as the galaxy main sequence and the IR/radio correlation, to characterise the radio properties of massive, high-redshift galaxies. The model shows excellent agreement with recent deep radio observations and naturally predicts a substantial population of massive, dust-obscured galaxies already in place at early epochs. In this chapter, we extend the SEMPER framework to SKA surveys by including an evolving starburst fraction and computing differential number counts at 1.4 GHz for both lensed and unlensed SFGs. Furthermore, we predict the cosmic star formation rate density (SFRD) traced by radio-emitting galaxies up to z≈10. Our results show that SKA surveys will probe the faintest flux-density regimes, dominated by galaxies powered by star formation, and that <20 hours of SKA-Mid Band 2 observations will recover at least ≈20

Context. The James Webb Space Telescope (JWST) is revolutionizing our understanding of the Universe by unveiling faint, near-infrared dropouts previously beyond our reach, ranging from exceptionally dusty sources to galaxies up to redshift z similar to 14. Aims. In this paper, we identify F200W-dropout objects in the Cosmic Evolution Early Release Science (CEERS) survey that are absent from existing catalogs. Our selection method can effectively identify obscured low-mass (logM(*)/M-circle dot <= 9) objects at z <= 6, massive dust-rich sources up to z similar to 12, and ultrahigh-redshift (z > 15) candidates. Our goal is to uncover promising targets for further studies using deep mid-infrared imaging and/or spectroscopic follow-ups. Methods. We utilize two photometric catalogs optimized for detecting faint, red objects. Primarily relying on NIRCam photometry from the latest CEERS data release and supplementing with mid-infrared/(sub)millimeter data when available, our analysis pipeline combines multiple SED-fitting codes, star formation histories, and the novel CosMix tool for astronomical stacking to maximize available photometric information. Results. Our work highlights three 2 < z < 3 dusty dwarf galaxies that have higher masses compared to the typical dusty dwarfs previously identified in CEERS. Additionally, we reveal five faint sources with a significant probability of lying above z > 15, with best-fit masses compatible with Lambda cold dark matter and a standard baryon-to-star conversion efficiency. We exploit these candidates to compute the z similar to 17 UV luminosity function, finding estimates in good agreement with other similar studies. Their bimodal redshift probability distributions suggest they could also be z < 1.5 dwarf galaxies with extreme dust extinction. We also identify a strong line emitter galaxy at z similar to 5 mimicking the near-infrared emission of a z similar to 13 galaxy. Conclusions. Our sample holds promising candidates for future follow-ups. Confirming ultrahigh-redshift galaxies or lower-redshift dusty dwarfs will offer valuable insights into early galaxy formation, evolution with their central black holes and the nature of dark matter, and/or cosmic dust production mechanisms in low-mass galaxies, and will help us to understand degeneracies and contamination in high-redshift object searches.

We present seeing-limited ( arcsecond ) near-infrared integral field spectroscopy data of the type-2 quasars, QSO2s, SDSS J135646.10+102609.0 (J1356) and SDSS J143029.89+133912.1 (J1430, the Teacup), both belonging to the Quasar Feedback, QSOFEED, sample. The nuclear K-band spectra (1.95-2.45 m) of these radio-quiet QSO2s reveal several emission lines, indicative of the presence of a warm molecular gas reservoir (T≥1000 K). We measure nuclear masses of rm H_2 =5.9, 4.1, and $1.5 in the inner arcsecond diameter region of the Teacup (∼1.3 kpc), J1356 north (J1356N), and south nuclei (∼1.8 kpc), respectively. The total warm mass budget is ∼ 4.5 in the Teacup and ∼ 1.3 in J1356N, implying warm-to-cold molecular gas ratios of 10^-6. The warm molecular gas kinematics, traced with the and S(2) emission lines, is consistent with that of the cold molecular phase, traced by ALMA CO emission at higher angular resolution ( arcsecond and arcsecond ). In J1430, we detect the blue- and red-shifted sides of a compact warm molecular outflow extending up to 1.9 kpc and with velocities of 450 In J1356 only the red-shifted side is detected, with a radius of up to 2.0 kpc and velocity of 370 The outflow masses are 2.6 and 1.5times 10^3 for the Teacup and J1356N, and the warm-to-cold gas ratios in the outflows are 0.8 and 1 times implying that the cold molecular phase dominates the mass budget. We measure warm molecular mass outflow rates of 6.2 and 2.9 times 10^ for the Teacup and J1356N, which are approximately 0.001% of the total mass outflow rate (ionized + cold and warm molecular). We find an enhancement of velocity dispersion in the residual dispersion map of the Teacup, both along and perpendicular to the compact radio jet direction. This enhanced turbulence can be reproduced by simulations of jet-ISM interactions.

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.

[Abridged] SFGs are the dominant population in the faint radio sky, corresponding to flux densities at 1.4 GHz < 0.1 mJy. A panchromatic approach is essential for selecting SFGs in the radio band and understanding star formation processes over cosmic time. Semi-empirical models are valuable tools to effectively study galaxy formation and evolution, relying on minimal assumptions and exploiting empirical relations between galaxy properties and enabling us to take full advantage of the recent progress in radio and optical/near-infrared (NIR) observations. In this paper, we develop the Semi-EMPirical model for Extragalactic Radio emission (SEMPER) to predict radio luminosity functions and number counts at 1.4 GHz and 150 MHz for SFGs. SEMPER is based on state-of-the-art empirical relations and combines the redshift-dependent galaxy stellar mass functions obtained from the recent COSMOS2020 catalogue, which exploits deep near-infrared observations, with up-to-date observed scaling relations, such as the galaxy main sequence and the mass-dependent far-infrared/radio correlation across cosmic time. Our luminosity functions are compared with recent observational determinations from several radio telescopes, along with previous semi-empirical models and simulations. Our semi-empirical model successfully reproduces the observed luminosity functions at 1.4 GHz and 150 MHz up to z∼ 5 and the most recent number count statistics from radio observations in the LoTSS deep fields. Our model, based on galaxies selected in the NIR, naturally predicts the presence of radio-selected massive and/or dust-obscured galaxies already in place at high redshift (z≳3.5), as suggested by recent results from JWST. Our predictions offer an excellent benchmark for upcoming updates from JWST and future ultra-deep radio surveys planned with the SKA and its precursors.

This work investigates the multi-wavelength properties of 165 4FGL blazars from the Fermi-LAT fourth source catalogue, looking for with counterparts in the Australian SKA Pathfinder (ASKAP) First Large Absorption Survey in HI (FLASH) continuum. Using high-resolution data from FLASH and complementary radio datasets, combined with archival Atacama Large Millimeter Array (ALMA) observations, we perform detailed spectral energy distribution (SED) analyses across cm-to-mm wavelengths. Our findings reveal that most blazars exhibit re-triggered peaked spectra, indicative of emission dominated by a single emitting region. Additionally, we identify strong correlations between radio and gamma-ray luminosities, highlighting the significant role of relativistic jets in these active galactic nuclei. The inclusion of spectroscopic redshifts from Sloan Digital Sky Survey (SDSS) and Gaia enables a comprehensive analysis of the evolutionary trends and physical characteristics of the sources. Furthermore, we report a tight Radio-X-ray Correlation for Flat Spectrum Radio Quasars, contrasting with the more scattered behaviour observed in BL-Lacs, reflecting their distinct accretion and jet-driving mechanisms. These results provide critical insights into the physics of blazars and their environments, paving the way for future studies with next-generation facilities like the SKA Observatory (SKAO) for radio observations and Cherenkov Telescope Array for gamma-ray studies.

Bolstered by upcoming data from new-generation observational campaigns, we are about to enter a new era in the study of how galaxies form and evolve. The unprecedented quantity of data that will be collected from distances that have only marginally been grasped up to now will require analytical tools designed to target the specific physical peculiarities of the observed sources and handle extremely large datasets. One powerful method to investigate the complex astrophysical processes that govern the properties of galaxies is to model their observed spectral energy distributions (SEDs) at different stages of evolution and times throughout the history of the Universe. To address these challenges, we have developed GalaPy, a new library for modelling and fitting SEDs of galaxies from the X-ray to the radio band, as well as the evolution of their components and dust attenuation and reradiation. On the physical side, GalaPy incorporates both empirical and physically motivated star formation histories (SFHs), state-of-the-art single stellar population synthesis libraries, a two-component dust model for attenuation, an age-dependent energy conservation algorithm to compute dust reradiation, and additional sources of stellar continuum such as synchrotron, nebular and free-free emission, as well as X-ray radiation from low-and high-mass binary stars. On the computational side, GalaPy implements a hybrid approach that combines the high performance of compiled C++ with the user-friendly flexibility of Python. Also, it exploits an object-oriented design via advanced programming techniques. GalaPy is the fastest SED-generation tool of its kind, with a peak performance of almost 1000 SEDs per second. The models are generated on the fly without relying on templates, thus minimising memory consumption. It exploits a fully Bayesian parameter space sampling, which allows for the inference of parameter posteriors and thereby facilitates the study of the correlations between the free parameters and the other physical quantities that can be derived from modelling. The application programming interface (API) and functions of GalaPy are under continuous development, with planned extensions in the near future. In this first work, we introduce the project and showcase the photometric SED fitting tools already available to users. GalaPy is available on the Python Package Index (PyPI) and comes with extensive online documentation and tutorials.

Context.Evolutionary models suggest that the initial growth phases of active galactic nuclei (AGN) and their central supermassive black holes (SMBHs) are dust-enshrouded and characterised by jet or wind outflows that should gradually clear the interstellar medium (ISM) in the host by heating and/or expelling the surrounding gas. eFEDSJ091157.4+014327 (z ∼ 0.6) was selected from X-ray samples of eROSITA (extended ROentgen Survey with an Imaging Telescope Array) for its characteristics: red colours, X-ray obscuration (NH= 2.7 × 1022cm−2) and luminous (LX = 6.5 × 1044erg s−1), similar to those expected in quasars with outflows. It hosts an ionised outflow as revealed by a broad [O III]λ5007 Å emission line in the SDSS integrated spectrum. For a proper characterisation of the outflow properties and their effects, we need spatially resolved information.Aims.We aim to explore the environment around the red quasar, morphology of the [O III] gas and characterise the kinematics, mass outflow rates and energetics within the system.Methods.We used spatially resolved spectroscopic data from Multi Unit Spectroscopic Explorer (MUSE) with an average seeing of 0.6″ to construct flux, velocity and velocity dispersion maps. Thanks to the spatially resolved [O III]λ5007 Å emission detected, we provide insights into the morphology and kinematics of the ionised gas and better estimates of the outflow properties.Results.We find that the quasar is embedded in an interacting and merging system with three other galaxies ∼50 kpc from its nucleus. Spatially resolved kinematics reveal that the quasar has extended ionised outflows of up to 9.2−0.4+1.2kpc with positive and negative velocities up to 1000 km s−1and −1200 km s−1, respectively. The velocity dispersion (W80) ranges from 600–1800 km s−1. We associate the presence of high-velocity components with the outflow. The total mass outflow rate is estimated to be ∼10M⊙yr−1, a factor of ∼3–7 higher than the previous findings for the same target and kinetic power of 2 × 1042erg s−1. Considering different AGN bolometric luminosities, the kinetic coupling efficiencies range from 0.01%–0.03% and the momentum boosts are ∼0.2.Conclusions.The kinetic coupling efficiency values are low, which indicates that the ionised outflow is not energetically relevant. These values don’t align with the theoretical predictions of both radiation-pressure-driven outflows and energy-conserving mechanisms. However, note that our results are based only on the ionised phase while theoretical predictions are multi-phase. Moreover, the mass loading factor of ∼5 is an indication that these outflows are more likely AGN-driven than star formation-driven.

We present MEGARA integral field unit (IFU) observations of five local type-2 quasars (QSO2s, z ∼ 0.1) from the Quasar Feedback (QSOFEED) sample. These active galactic nuclei (AGN) have bolometric luminosities of 1045.5 − 46 erg s−1 and stellar masses of ∼1011 M⊙. The LR-V grating of MEGARA allows us to explore the kinematics of the ionized gas through the [O III]λ5007 Å emission line. The nuclear spectra of the five QSO2s, extracted in a circular aperture of ∼1.2″ (∼2.2 kpc) in diameter, matching the resolution of these seeing-limited observations, show signatures of high velocity winds in the form of broad (full width at half maximum, 1300 ≤ FWHM ≤ 2240 km s−1) and blueshifted components. We found that four out of the five QSO2s present outflows that we can resolve with our seeing-limited data, and they have radii ranging from 3.1 to 12.6 kpc. In the case of the two QSO2s with extended radio emission, we found that it is well aligned with the outflows, suggesting that low-power jets might be compressing and accelerating the ionized gas in these radio-quiet QSO2s. In the four QSO2s with spatially resolved outflows, we measured ionized mass outflow rates of 3.3–6.5 M⊙ yr−1 when we used [S II]-based densities, and of 0.7–1.6 M⊙ yr−1 when trans-auroral line-based densities were considered instead. We compared them with the corresponding molecular mass outflow rates (8–16 M⊙ yr−1), derived from CO(2–1) ALMA observations at 0.2″ resolution. The cold molecular outflows carry more mass than their ionized counterparts. However, both phases show lower outflow mass rates than those expected from observational scaling relations where uniform assumptions on the outflow properties were adopted. This might be indicating that the AGN luminosity is not the only driver of massive outflows and/or that these relations need to be rescaled using accurate outflow properties (i.e., electron density and radius). We did not find a significant impact of the outflows on the global star formation rates when considering the energy budget of the molecular and ionized outflows together. However, spatially resolved measurements of recent star formation in these targets are needed in order to evaluate this fairly, considering the dynamical timescales of the outflows, of 3–20 Myr for the ionized gas and 1–10 Myr for the molecular gas.

Aims.The main goal of this work is to test the results of a methodological improvement in the measurement of the magnification bias signal on a sample of submillimeter galaxies. In particular, we investigate the constraining power of cosmological parameters within the ΛCDM model. We also discuss important points that can affect the results.Methods.We measured the angular cross-correlation function between a sample of foreground GAMA II galaxies in a single wide spectroscopic redshift bin of 0.2 < z < 0.8 and a sample of background submillimeter galaxies fromHerschel-ATLAS. We focused on the photometric redshift range of 1.2 < z < 4.0, with an improved methodological framework. Interpreting the weak lensing signal within the halo model formalism and performing a Markov chain Monte Carlo (MCMC) algorithm, we obtained the posterior distribution of both the halo occupation distribution and cosmological parameters within a flat ΛCDM model. Our analysis was also performed with additional galaxy clustering information via a foreground angular auto-correlation function.Results.We observed an overall remarkable improvement in terms of uncertainties in both the halo occupation distribution and cosmological parameters with respect to previous results. A priori knowledge aboutβ, the logarithmic slope of the background integral number counts, is found to be paramount to derive constraints onσ8when using the cross-correlation data alone. Assuming a physically motivated prior distribution forβ, we obtain mean values of Ωm = 0.23−0.06+0.03and σ8 = 0.79−0.10+0.10and an unconstrained distribution for the Hubble constant. These results are likely to suffer from sampling variance, since one of the fields, G15, appears to have an anomalous behavior with a systematically higher cross-correlation. We find that removing it from the sample yields mean values of Ωm = 0.27−0.04+0.02andσ8 = 0.72−0.04+0.04and, for the first time, a (loose) restriction of the Hubble constant is obtained via this observable:h = 0.79−0.14+0.13. The addition of the angular auto-correlation of the foreground sample in a joint analysis tightens the constraints, but also reveals a discrepancy between both observables that might be an aggravated consequence of sampling variance or due to the presence of unmodeled aspects on small and intermediate scales.

The black hole-and-galaxy (BH-galaxy) co-evolution paradigm predicts a phase where most of the star formation (SF) and BH accretion takes place in gas-rich environments, namely, in what are likely to be very obscured conditions. In the first phase of this growth, some of the galactic gas is funnelled toward the centre of the galaxy and is accreted into the supermassive BH, triggering active galactic nucleus (AGN) activity. The large quantity of gas and dust hides the emission and the AGN appears as an obscured (type 2) AGN. The degree of obscuration in type 2 AGNs may even reach values as high as NH > 1024 cm−2 (i.e., Compton-thick, CT). Population synthesis models of the X-ray background (XRB) suggest that a large population of CT-AGN is, in fact, needed to explain the still unresolved XRB emission at energy above 20 keV. In this work, we investigated the properties of 94 [Ne V]3426 Å-selected type 2 AGN in COSMOS at z = 0.6 − 1.2, performing optical-to-far-infrared (FIR) spectral energy distribution (SED) fitting of COSMOS2020 photometric data to estimate the AGN bolometric luminosity and stellar mass, star formation rate, age of the oldest stars, and molecular gas mass for their host-galaxy. In addition, we performed an X-ray spectral analysis of the 36 X-ray-detected sources to obtain reliable values of the AGN obscuration and intrinsic luminosity, as well as to constrain the AGN properties of the X-ray-undetected sources. We found that more than two-thirds of our sample is composed of very obscured sources (NH > 1023 cm−2), with about 20% of the sources being candidate CT-AGN and half being AGNs in a strong phase of accretion (λEdd > 0.1). We built a mass- and redshift-matched control sample and its comparison with the [Ne V] sample indicates that the latter has a higher fraction of sources within the main sequence of star-forming galaxies and shows little evidence for AGNs quenching the SF. As the two samples have similar amounts of cold gas available to fuel the SF, this difference points towards a higher efficiency in forming stars in the [Ne V]-selected sample. The comparison with the prediction from the in situ co-evolution model suggests that [Ne V] is an effective tool for selecting galaxies in the obscured growth phase of the BH-galaxy co-evolution paradigm. We find that the “quenching phase” is still to come for most of the sample and only few galaxies show evidence of quenched SF activity.

The spectral energy distribution (SED) of low-luminosity active galactic nuclei (LLAGN) presents unique challenges as the emission from these objects is comparable to the radiation from their host galaxy and the accretion physics involved is particularly complex. This study introduces a novel CIGALE module specifically designed to address these challenges. The module combines the empirical L-X-L-12 mu m relationship with physically motivated accretion models, such as advection-dominated accretion flows (ADAFs) and truncated accretion disks, providing a more accurate depiction of LLAGN central engine emission. A mock analysis of the module revealed good recovery of true parameters, with only a slight bias toward higher input values, further validating its reliability. We tested the module on a sample of 50 X-ray-detected local galaxies, including low-ionization nuclear emission-line regions (LINERs) and Seyferts, and demonstrated its capacity to accurately estimate bolometric luminosities, even in the presence of significant galaxy contamination. Notably, the previous X-ray module failed to provide AGN solutions for this sample, stressing the need for a novel approach. Comparisons with mid-luminosity AGN datasets confirm the module's robustness and applicability up to L-X < 10(45) erg/s. We also expanded the X-ray-to-bolometric correction formula, making it applicable to AGN spanning ten orders of magnitude in luminosity, and revealing lower k(X) values for LLAGN than typically assumed. Additionally, our analysis of the alpha(ox) index, which represents the slope between UV and X-ray emissions, uncovered trends that differ from those observed in high-luminosity AGN. Unlike quasars, where alpha(ox) correlates with lambda(Edd), LLAGN exhibit nearly constant or weakly correlated alpha(ox) values, suggesting a shift in accretion physics and photon production mechanisms in low-luminosity regimes. These results underscore the importance of a multiwavelength approach in AGN studies and reveal distinct behaviors in LLAGN compared to quasars. Our findings significantly advance our understanding of LLAGN and offer a comprehensive framework for future research to complete the AGN population census.

Supermassive black holes require a reservoir of cold gas at the centre of their host galaxy in order to accrete and shine as active galactic nuclei (AGN). Major mergers have the ability to drive gas rapidly inwards, but observations trying to link mergers with AGN have found mixed results due to the difficulty of consistently identifying galaxy mergers in surveys. This study applies deep learning to this problem, using convolutional neural networks trained to identify simulated post -merger galaxies from survey-realistic imaging. This provides a fast and repeatable alternative to human visual inspection. Using this tool, we examine a sample of similar to 8500 Seyfert 2 galaxies ( L [ O (III) ] similar to 10(38 . 5-42) erg s (-1)) at z < 0.3 in the Sloan Digital Sky Survey and find a merger fraction of 2 . 19 (+0.21)(-0.17) percent compared with inactive control galaxies, in which we find a merger fraction of 2.96(-0.20)(+0.26 )per cent, indicating an overall lack of mergers among AGN hosts compared with controls. However, matching the controls to the AGN hosts in stellar mass and star formation rate reveals that AGN hosts in the star -forming blue cloud exhibit a similar to 2 x merger enhancement over controls, while those in the quiescent red sequence have significantly lower relative merger fractions, leading to the observed overall deficit due to the differing M (& lowast;)-SFR distributions. We conclude that while mergers are not the dominant trigger of all low -luminosity, obscured AGN activity in the nearby Univ erse, the y are more important to AGN fuelling in galaxies with higher cold gas mass fractions as traced through star formation.

The spectral energy distribution (SED) of low-luminosity active galactic nuclei (LLAGN) presents challenges due to their faint emissions and the complexity of their accretion processes. This study introduces a new CIGALE module tailored for LLAGN, combining the empirical L_X-L_12μ m relationship with physical models like advection-dominated accretion flows (ADAFs) and truncated accretion disks. This module yields a refined depiction of LLAGN emissions, and a mock analysis shows reliable parameter recovery, with only minor biases. We tested the module on a sample of 50 X-ray-detected local galaxies, including LINERs and Seyferts, where it demonstrated good estimation of bolometric luminosities, even in the presence of significant galaxy contamination. Notably, the previous X-ray module failed to provide AGN solutions for this sample, stressing the need for a novel approach. Comparisons with mid-luminosity AGN confirm the module's robustness and applicability to AGN up to L_X < 10^45 erg/s. We also expanded the X-ray to bolometric correction formula, making it applicable to AGN spanning ten orders of magnitude in luminosity, and revealing lower k_X values than typically assumed. Additionally, our analysis of the α_ox index, representing the slope between UV and X-ray emissions, uncovered trends that differ from those observed in high-luminosity AGN, suggesting a shift in accretion physics and photon production mechanisms in low-luminosity regimes. These results underscore the importance of a multiwavelength approach in AGN studies and reveal distinct behaviors in LLAGN compared to quasars. Our findings significantly advance the understanding of LLAGN and offer a comprehensive framework for future research aimed at completing the census of the AGN population.

Context. The phenomenon of magnification bias can induce a non-negligible angular correlation between two samples of galaxies with nonoverlapping redshift distributions. This signal is particularly clear when background submillimeter galaxies are used, and has been shown to constitute an independent cosmological probe. Aims. This work extends prior studies on the submillimeter galaxy magnification bias to the massive neutrino scenario, with the aim being to assess its sensitivity as a cosmological observable to the sum of neutrino masses. Methods. The measurements of the angular cross-correlation function between moderate redshift GAMA galaxies and high-redshift submillimeter H-ATLAS galaxies are fit to the weak lensing prediction down to the arcmin scale. The signal is interpreted under the halo model, which is modified to accommodate massive neutrinos. We discuss the impact of the choice of cosmological parametrization on the sensitivity to neutrino masses. Results. The currently available data on the magnification bias affecting submillimeter galaxies are sensitive to neutrino masses when a cosmological parametrization in terms of the primordial amplitude of the power spectrum ( A s ) is chosen over the local root mean square of smoothed linear density perturbations ( σ 8 ). A clear upper limit on the sum of neutrino masses can be derived if the value of A s is either fixed or assigned a narrow Gaussian prior, a behavior that is robust against changes to the chosen value.

We have carried out HST snapshot observations at 1.1 μm of 281 candidate strongly lensed galaxies identified in the wide-area extragalactic surveys conducted with the Herschel space observatory. Our candidates comprise systems with flux densities at 500 μmS_500≥ 80 mJy. We model and subtract the surface brightness distribution for 130 systems, where we identify a candidate for the foreground lens candidate. After combining visual inspection, archival high-resolution observations, and lens subtraction, we divide the systems into different classes according to their lensing likelihood. We confirm 65 systems to be lensed. Of these, 30 are new discoveries. We successfully perform lens modelling and source reconstruction on 23 systems, where the foreground lenses are isolated galaxies and the background sources are detected in the HST images. All the systems are successfully modelled as a singular isothermal ellipsoid. The Einstein radii of the lenses and the magnifications of the background sources are consistent with previous studies. However, the background source circularised radii (between 0.34 kpc and 1.30 kpc) are ∼3 times smaller than the ones measured in the sub-mm/mm for a similarly selected and partially overlapping sample. We compare our lenses with those in the SLACS survey, confirming that our lens-independent selection is more effective at picking up fainter and diffuse galaxies and group lenses. This sample represents the first step towards characterising the near-IR properties and stellar masses of the gravitationally lensed dusty star-forming galaxies.