Search

X-ray luminosity functions (XLFs) of Active Galactic Nuclei (AGN) trace the growth and evolution of supermassive black hole populations across cosmic time, however, current XLF models are poorly constrained at redshifts of z>6, with a lack of spectroscopic constraints at these high redshifts. In this work we \redit{place limits} on the bright-end of the XLF at z=5.7-6.4 using high-redshift AGN identified within the Extragalactic Serendipitous Swift Survey (ExSeSS) catalogue. Within ExSeSS we find one serendipitously X-ray detected z>6 AGN, ATLAS J025.6821-33.4627, with an X-ray luminosity of $L_\mathrm{X}=8.47^{+3.40}_{-3.13}\times10^{44}\mathrm{erg.s^{-1}}$ and $z=6.31\pm0.03$ making it the highest redshift, spectroscopically confirmed, serendipitously X-ray detected quasar known to date. We also calculate an upper limit on the space density at higher luminosities where no additional sources are found, enabling us to place constraints on the shape of the XLF. Our results are consistent with the rapid decline in the space densities of high-luminosity AGN toward high redshift as predicted by extrapolations of existing parametric models of the XLF. We also find that our X-ray based measurements are consistent with estimates of the bolometric quasar luminosity function based on UV measurements at $z\gtrsim6$, although they require a large X-ray to bolometric correction factor at these high luminosities., 10pages, 6 figures. Resubmitted to MNRAS, following referee comments

We study the properties of the Sydney University Molonglo Sky Survey (SUMSS) 843~MHz radio AGN population in galaxy clusters from two large catalogs created using the Dark Energy Survey (DES): $\sim$11,800 optically selected RM-Y3 and $\sim$1,000 X-ray selected MARD-Y3 clusters. We show that cluster radio loud AGN are highly concentrated around cluster centers to $z\sim1$. We measure the halo occupation number for cluster radio AGN above a threshold luminosity, finding that the number of radio AGN per cluster increases with cluster halo mass as $N\propto M^{1.2\pm0.1}$ ($N\propto M^{0.68\pm0.34}$) for the RM-Y3 (MARD-Y3) sample. Together, these results indicate that radio mode feedback is favoured in more massive galaxy clusters. Using optical counterparts for these sources, we demonstrate weak redshift evolution in the host broad band colors and the radio luminosity at fixed host galaxy stellar mass. We use the redshift evolution in radio luminosity to break the degeneracy between density and luminosity evolution scenarios in the redshift trend of the radio AGN luminosity function (LF). The LF exhibits a redshift trend of the form $(1+z)^\gamma$ in density and luminosity, respectively, of $\gamma_{\rm D}=3.0\pm0.4$ and $\gamma_{\rm P}=0.21\pm0.15$ in the RM-Y3 sample, and $\gamma_{\rm D}=2.6\pm0.7$ and $\gamma_{\rm P}=0.31\pm0.15$ in MARD-Y3. We discuss the physical drivers of radio mode feedback in cluster AGN, and we use the cluster radio galaxy LF to estimate the average radio-mode feedback energy as a function of cluster mass and redshift and compare it to the core ($, Comment: 20 pages, 15 figures Replaced with published version

We include a fully coupled treatment of metal and dust enrichment into the DELPHI semi-analytic model of galaxy formation to explain the dust content of 13 Lyman break galaxies (LBGs) detected by the Atacama Large millimetre Array (ALMA) REBELS Large Program at z similar or equal to 7. We find that the galaxy dust mass, M-d, is regulated by the combination of Type II supernova dust production, astration, shock destruction, and ejection in outflows; grain growth (with a standard time-scale tau(0) = 30 Myr) plays a negligible role. The model predicts a dust-to-stellar mass ratio of similar to 0.07-0.1 per cent and a UV-to-total star formation rate relation such that log(psi(UV)) = -0.05 [log(psi)](2) + 0.86 log(psi) - 0.05 (implying that 55-80 per cent of the star formation is obscured) for REBELS galaxies with stellar mass M-* = 10(9)-10(10)M(circle dot). This relation reconciles the intrinsic UV luminosity of LBGs with their observed luminosity function at z = 7. However, 2 out of the 13 systems show dust-to-stellar mass ratios (similar to 0.94-1.1 per cent) that are up to 18 times larger than expected from the fiducial relation. Due to the physical coupling between dust and metal enrichment, even decreasing to to very low values (0.3 Myr) only increases the dust-to-stellar mass ratio by a factor of similar to 2. Given that grain growth is not a viable explanation for such high observed ratios of the dust-to-stellar mass, we propose alternative solutions.

Feedback from low-excitation radio galaxies (LERGs) plays a key role in the lifecycle of massive galaxies in the local Universe; their evolution, and the impact of these active galactic nuclei on early galaxy evolution, however, remain poorly understood. We use a sample of 10481 LERGs from the first data release of the LOFAR Two-meter Sky Survey Deep Fields, covering $\sim$ 25 deg$^2$, to present the first measurement of the evolution of the radio luminosity function (LF) of LERGs out to $z\sim2.5$; this shows relatively mild evolution. We split the LERGs into those hosted by quiescent and star-forming galaxies, finding a new dominant population of LERGs hosted by star-forming galaxies at high redshifts. The incidence of LERGs in quiescent galaxies shows a steep dependence on stellar-mass out to $z \sim1.5$, consistent with local Universe measurements of accretion occurring from cooling of hot gas haloes. The quiescent-LERGs dominate the LFs at $z, 26 pages, 16 figures, accepted for publication in MNRAS. LF data available at: https://github.com/rohitk-10/AGN_LF_Kondapally22 . Author list error corrected in updated version

In Galaxy And Mass Assembly Data Release 4 (GAMA DR4), we make available our full spectroscopic redshift sample. This includes 248682 galaxy spectra, and, in combination with earlier surveys, results in 330542 redshifts across five sky regions covering ~250deg^2. The redshift density, is the highest available over such a sustained area, has exceptionally high completeness (95 per cent to r_KIDS=19.65mag), and is well suited for the study of galaxy mergers, galaxy groups, and the low redshift (z, Comment: Accepted for publication in MNRAS. GAMA Data Release 4 is available at: http://www.gama-survey.org/dr4/

This paper presents a new search for $z\geq7.5$ galaxies using the COSMOS2020 photometric catalogues. Finding galaxies at the reionization epoch through deep imaging surveys remains observationally challenging. The larger area covered by ground-based surveys like COSMOS enables the discovery of the brightest galaxies at these high redshifts. Covering $1.4$deg$^2$, our COSMOS catalogues were constructed from the latest UltraVISTA data release (DR4) combined with the final Spitzer/IRAC COSMOS images and the Hyper-Suprime-Cam Subaru Strategic Program DR2 release. We identify $17$ new $7.5, Comment: 25 pages, 11 figures, 4 tables, accepted in A&A

We include a fully coupled treatment of metal and dust enrichment into the Delphi semi-analytic model of galaxy formation to explain the dust content of 13 Lyman Break Galaxies (LBGs) detected by the Atacama Large millimetre Array (ALMA) REBELS Large Program at $z\simeq 7$. We find that the galaxy dust mass, $M_d$, is regulated by the combination of SNII dust production, astration, shock destruction, and ejection in outflows; grain growth (with a standard timescale $\tau_0= 30$ Myr) plays a negligible role. The model predicts a dust-to-stellar mass ratio of $\sim 0.07-0.1\%$ and a UV-to-total star formation rate relation such that $log (\psi_{\rm UV}) = -0.05 ~[log (\psi)]^{2} + 0.86 ~log(\psi) -0.05$ (implying that 55-80\% of the star formation is obscured) for REBELS galaxies with stellar mass $M_* = 10^{9-10} M_\odot$. This relation reconciles the intrinsic UV luminosity of LBGs with their observed luminosity function at $z=7$. However, 2 out of the 13 systems show dust-to-stellar mass ratios ($\sim 0.94-1.1\%$) that are up to $18\times$ larger than expected from the fiducial relation. Due to the physical coupling between dust and metal enrichment, even decreasing $\tau_0$ to very low values (0.3 Myr) only increases the dust-to-stellar mass ratio by a factor $ \sim 2$. Given that grain growth is not a viable explanation for such high observed ratios of the dust-to-stellar mass, we propose alternative solutions., Comment: Accepted to MNRAS

[Aims]: In this paper, we aim to study the main properties and luminosity function (LF) of the [O II]3727 emitters detected in the OTELO survey in order to characterise the star formation processes in low-mass galaxies at z ∼ 1.43 and to constrain the faint-end of the LF. [Methods]: Here, we describe the selection method and analysis of the emitters obtained from narrow-band scanning techniques. In addition, we present several relevant properties of the emitters and discuss the selection biases and uncertainties in the determination of the LF and the star formation rate density (SFRD). [Results]: We confirmed a total of 60 sources from a preliminary list of 332 candidates as [O II]3727 emitters. Approximately 93% of the emitters have masses in the range of 108, JAdD thanks the Instituto de Astrofísica de Canarias (IAC) for its support through the Programa de Excelencia Severo Ochoa and the Gobierno de Canarias for the Programa de Talento Tricontinental grant. This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under the grants AYA2013-46724-P, AYA2014-58861-C3-1-P, AYA2014-58861-C3-2-P, AYA2014-58861-C3-3-P, AYA2016-75808-R, AYA2016-75931-C2-1-P, AYA2016-75931-C2-2-P, and MDM-2017-0737 (Unidad de Excelencia María de Maeztu, CAB). This work was supported by the project Evolution of Galaxies, of reference AYA2017-88007-C3-1-P, within the “Programa estatal de fomento de la investigación científica y técnica de excelencia del Plan Estatal de Inves-tigación Científica y Técnica y de Innovación (2013–2016)” of the “Agencia Estatal de Investigación del Ministerio de Ciencia, Innovación y Universidades”, and co-financed by the FEDER “Fondo Europeo de Desarrollo Regional”. This article is based on observations made with the Gran Telescopio Canarias (GTC) at Roque de los Muchachos Observatory of the Instituto de Astrofísica de Canarias on the island of La Palma. This study makes use of data from AEGIS, a multi-wavelength sky survey conducted with the Chandra, GALEX, Hubble, Keck, CFHT, MMT, Subaru, Palomar, Spitzer, VLA, and other telescopes, and is supported in part by the NSF, NASA, and the STFC. Based on observations obtained with MegaPrime/MegaCam, a joint project of the CFHT and CEA/IRFU, at the Canada–France–Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l’Univers of the Centre National de la Recherche Sci-entifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at Terapix available at the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. Based on observations obtained with WIRCam, a joint project of CFHT, Taiwan, Korea, Canada, France, at the Canada–France–Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de l’Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX, the WIRDS (WIRcam Deep Survey) consortium, and the Canadian Astronomy Data Centre. This research was supported by a grant from the Agence Nationale de la Recherche ANR-07-BLAN-0228., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (SEV-2017-0709).

We use KiDS weak lensing data to measure variations in mean halo mass as a function of several key galaxy properties (namely stellar colour, specific star formation rate, Sérsic index, and effective radius) for a volume-limited sample of GAMA galaxies in a narrow stellar mass range [M* ∼ (2–5) × 1010 M⊙]. This mass range is particularly interesting, inasmuch as it is where bimodalities in galaxy properties are most pronounced, and near to the break in both the galaxy stellar mass function and the stellar-to-halo mass relation (SHMR). In this narrow mass range, we find that both size and Sérsic index are better predictors of halo mass than either colour or SSFR, with the data showing a slight preference for Sérsic index. In other words, we find that mean halo mass is more tightly correlated with galaxy structure than either past star formation history or current star formation rate. Our results lead to an approximate lower bound on the dispersion in halo masses among log M* ≈ 10.5 galaxies: We find that the dispersion is ≳0.3 dex. This would imply either that offsets from the mean SHMR are closely coupled to size/structure or that the dispersion in the SHMR is larger than what past results have suggested. Our results thus provide new empirical constraints on the relationship between stellar and halo mass assembly at this particularly interesting mass range.

One key problem in astrophysics is understanding how and why galaxies switch off their star formation, building the quiescent population that we observe in the local Universe. From the GAMA and VIPERS surveys, we use spectroscopic indices to select quiescent and candidate transition galaxies. We identify potentially rapidly transitioning post-starburst galaxies, and slower transitioning green-valley galaxies. Over the last 8 Gyrs the quiescent population has grown more slowly in number density at high masses (M$_*>10^{11}$M$_\odot$) than at intermediate masses (M$_*>10^{10.6}$M$_\odot$). There is evolution in both the post-starburst and green valley stellar mass functions, consistent with higher mass galaxies quenching at earlier cosmic times. At intermediate masses (M$_*>10^{10.6}$M$_\odot$) we find a green valley transition timescale of 2.6 Gyr. Alternatively, at $z\sim0.7$ the entire growth rate could be explained by fast-quenching post-starburst galaxies, with a visibility timescale of 0.5 Gyr. At lower redshift, the number density of post-starbursts is so low that an unphysically short visibility window would be required for them to contribute significantly to the quiescent population growth. The importance of the fast-quenching route may rapidly diminish at $z10^{11}$M$_\odot$), there is tension between the large number of candidate transition galaxies compared to the slow growth of the quiescent population. This could be resolved if not all high mass post-starburst and green-valley galaxies are transitioning from star-forming to quiescent, for example if they rejuvenate out of the quiescent population following the accretion of gas and triggering of star formation, or if they fail to completely quench their star formation., Comment: 19 pages, 11 figures, 3 tables. Accepted for publication in MNRAS. Updated to match published version

How do galaxy properties (such as stellar mass, luminosity, star formation rate, and morphology) and their evolution depend on the mass of their host dark matter halo? Using the Galaxy and Mass Assembly (GAMA) group catalogue, we address this question by exploring the dependence on host halo mass of the luminosity function (LF) and stellar mass function (SMF) for grouped galaxies subdivided by colour, morphology and central/satellite. We find that spheroidal galaxies in particular dominate the bright and massive ends of the LF and SMF, respectively. More massive haloes host more massive and more luminous central galaxies. The satellite LF and SMF respectively show a systematic brightening of characteristic magnitude, and increase in characteristic mass, with increasing halo mass. In contrast to some previous results, the faint-end and low-mass slopes show little systematic dependence on halo mass. Semi-analytic models and simulations show similar or enhanced dependence of central mass and luminosity on halo mass. Faint and low-mass simulated satellite galaxies are remarkably independent of halo mass, but the most massive satellites are more common in more massive groups. In the first investigation of low-redshift LF and SMF evolution in group environments, we find that the red/blue ratio of galaxies in groups has increased since redshift $z \approx 0.3$ relative to the field population. This observation strongly suggests that quenching of star formation in galaxies as they are accreted into galaxy groups is a significant and ongoing process., Comment: 22 pages, 18 figures, MNRAS in press

We use imaging from the first three years of the Dark Energy Survey to characterize the dynamical state of 288 galaxy clusters at $0.1 \lesssim z \lesssim 0.9$ detected in the South Pole Telescope (SPT) Sunyaev-Zeldovich (SZ) effect survey (SPT-SZ). We examine spatial offsets between the position of the brightest cluster galaxy (BCG) and the center of the gas distribution as traced by the SPT-SZ centroid and by the X-ray centroid/peak position from Chandra and XMM data. We show that the radial distribution of offsets provides no evidence that SPT SZ-selected cluster samples include a higher fraction of mergers than X-ray-selected cluster samples. We use the offsets to classify the dynamical state of the clusters, selecting the 43 most disturbed clusters, with half of those at $z \gtrsim 0.5$, a region seldom explored previously. We find that Schechter function fits to the galaxy population in disturbed clusters and relaxed clusters differ at $z>0.55$ but not at lower redshifts. Disturbed clusters at $z>0.55$ have steeper faint-end slopes and brighter characteristic magnitudes. Within the same redshift range, we find that the BCGs in relaxed clusters tend to be brighter than the BCGs in disturbed samples, while in agreement in the lower redshift bin. Possible explanations includes a higher merger rate, and a more efficient dynamical friction at high redshift. The red-sequence population is less affected by the cluster dynamical state than the general galaxy population., 21 pages, 12 Figures, 4 Tables. Accepted for publication in MNRAS

A significant fraction of all $\gamma$-ray sources detected by the Large Area Telescope aboard the \fer\ satellite is still lacking a low-energy counterpart. In addition, there is still a large population of $\gamma$-ray sources with associated low-energy counterparts that lack firm classifications. In the last 10 years we have undertaken an optical spectroscopic campaign to address the problem of unassociated/unidentified $\gamma$-ray sources (UGSs), mainly devoted to observing blazars and blazar candidates because they are the largest population of $\gamma$-ray sources associated to date. Here we describe the overall impact of our optical spectroscopic campaign on sources associated in \fer-LAT catalogs, coupled with objects found in the literature. In the literature search, we kept track of efforts by different teams that presented optical spectra of counterparts or potential counterparts of \fer-LAT catalog sources. Our summary includes an analysis of an additional 30 newly-collected optical spectra of counterparts or potential counterparts of \fer-LAT sources of previously unknown nature.New spectra were acquired at the Blanco 4-m and OAN-SPM 2.1-m telescopes, and those available in the Sloan Digital Sky Survey (data release 15) archive. All new sources with optical spectra analyzed here are classified as blazars. Thanks to our campaign, we altogether discovered and classified 394 targets with an additional 123 objects collected from a literature search. We began our optical spectroscopic campaign between the release of the second and third \fer-LAT source catalogs (2FGL and 3FGL, respectively), and classified about 25\% of the sources with uncertain nature and discovered a blazar-like potential counterpart for $\sim$10\% of UGSs listed therein. In the 4FGL catalog, about 350 \fer-LAT sources are classified to date thanks to our campaign. [incomplete abstract], Comment: 31 pages, 12 tables, 32 figures, 2 appendices, accepted for publication on A&A (pre-proofs version)

http://www.iac.es/proyecto/otelo Aims. We take advantage of the capability of the OTELO survey to obtain the Hα luminosity function (LF) at z ∼ 0.40. Because of the deepest coverage of OTELO, we are able to determine the faint end of the LF, and thus better constrain the star formation rate and the number of galaxies at low luminosities. The AGN contribution to this LF is estimated as well. Methods. We make use of the multiwavelength catalogue of objects in the field compiled by the OTELO survey, which is unique in terms of minimum flux and equivalent width. We also take advantage of the pseudo-spectra built for each source, which allow the identification of emission lines and the discrimination of different types of objects. Results. The Hα luminosity function at z ∼ 0.40 is obtained, which extends the current faint end by almost 1 dex, reaching minimal luminosities of log10Llim = 38.5 erg s−1 (or ∼0.002 M⊙ yr−1). The AGN contribution to the total Hα luminosity is estimated. We find that no AGN should be expected below a luminosity of log10L = 38.6 erg s−1. From the sample of non-AGN (presumably, pure SFG) at z ∼ 0.40 we estimated a star formation rate density of ρSFR = 0.012 ± 0.005 M⊙ yr−1 Mpc−3. This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under the grants AYA2013- 46724- P, AYA2014 58861-C3-1- P, AYA2014-58861-C3-2-P, AYA2014-58861-C3-3- P, AYA2016 -75808-R, AYA2016-75931-C2-2-P, AYA2017-88007-C3-1-P, and AYA2017 -88007-C3-2- P. Based on observations made with the Gran Telescopio Canarias installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in the island of La Palma. The authors thanks the anonymous referee for her/his feedback and suggestions; With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737). Peer review

Context: Dwarf galaxies are the most common type of galaxies in galaxy clusters. Due to their low mass, they are more vulnerable to environmental effects than massive galaxies, and are thus optimal for studying the effects of the environment on galaxy evolution. By comparing the properties of dwarf galaxies with different masses, morphological types, and cluster-centric distances we can obtain information about the physical processes in clusters that play a role in the evolution of these objects and shape their properties. The Fornax Deep Survey Dwarf galaxy Catalog (FDSDC) includes 564 dwarf galaxies in the Fornax cluster and the in-falling Fornax A subgroup. This sample allows us to perform a robust statistical analysis of the structural and stellar population differences in the range of galactic environments within the Fornax cluster. Aims: By comparing our results with works concerning other clusters and the theoretical knowledge of the environmental processes taking place in galaxy clusters, we aim to understand the main mechanisms transforming galaxies in the Fornax cluster. Methods: We have exploited the FDSDC to study how the number density of galaxies, galaxy colors and structure change as a function of the cluster-centric distance, used as a proxy for the galactic environment and in-fall time. We also used deprojection methods to transform the observed shape and density distributions of the galaxies into the intrinsic physical values. These measurements are then compared with predictions of simple theoretical models of the effects of harassment and ram pressure stripping on galaxy structure. We used stellar population models to estimate the stellar masses, metallicities and ages of the dwarf galaxies. We compared the properties of the dwarf galaxies in Fornax with those in the other galaxy clusters with different masses. Results: We present the standard scaling relations for dwarf galaxies, which are the size-luminosity, Sérsic n-magnitude and color-magnitude relations. New in this paper is that we find a different behavior for the bright dwarfs (−18.5 mag < Mr′ < −16 mag) as compared to the fainter ones (Mr′ gt −16 mag): While considering galaxies in the same magnitude-bins, we find that, while for fainter dwarfs the g′−r′ color is redder for lower surface brightness objects (as expected from fading stellar populations), for brighter dwarfs the color is redder for the higher surface brightness and higher Sérsic n objects. The trend of the bright dwarfs might be explained by those galaxies being affected by harassment and by slower quenching of star formation in their inner parts. As the fraction of early-type dwarfs with respect to late-types increases toward the central parts of the cluster, the color-surface brightness trends are also manifested in the cluster-centric trends, confirming that it is indeed the environment that changes the galaxies. We also estimate the strength of the ram-pressure stripping, tidal disruption, and harassment in the Fornax cluster, and find that our observations are consistent with the theoretically expected ranges of galaxy properties where each of those mechanisms dominate. We furthermore find that the luminosity function, color–magnitude relation, and axis-ratio distribution of the dwarfs in the center of the Fornax cluster are similar to those in the center of the Virgo cluster. This indicates that in spite of the fact that the Virgo is six times more massive, their central dwarf galaxy populations appear similar in the relations studied by us. This article has an erratum: https://www.aanda.org/10.1051/0004-6361/201935231e

We present the Tiered Radio Extragalactic Continuum Simulation (T-RECS): a new simulation of the radio sky in continuum, over the 150 MHz-20 GHz range. T-RECS models two main populations of radio galaxies: Active Galactic Nuclei (AGNs) and Star-Forming Galaxies (SFGs), and corresponding sub-populations. Our model also includes polarized emission over the full frequency range, which has been characterised statistically for each population using the available information. We model the clustering properties in terms of probability distributions of hosting halo masses, and use lightcones extracted from a high-resolution cosmological simulation to determine the positions of haloes. This limits the sky area for the simulations including clustering to a 25deg2 field of view. We compare luminosity functions, number counts in total intensity and polarization, and clustering properties of our outputs to up-to-date compilations of data and find a very good agreement. We deliver a set of simulated catalogues, as well as the code to produce them, which can be used for simulating observations and predicting results from deep radio surveys with existing and forthcoming radio facilities, such as the Square Kilometre Array (SKA)., 20 pages, 11 figures, accepted by MNRAS

[Aims] We take advantage of the capability of the OTELO survey to obtain the H alpha luminosity function (LF) at z similar to 0.40. Because of the deepest coverage of OTELO, we are able to determine the faint end of the LF, and thus better constrain the star formation rate and the number of galaxies at low luminosities. The AGN contribution to this LF is estimated as well. [Methods] We make use of the multiwavelength catalogue of objects in the field compiled by the OTELO survey, which is unique in terms of minimum flux and equivalent width. We also take advantage of the pseudo-spectra built for each source, which allow the identification of emission lines and the discrimination of different types of objects. [Results] The H alpha luminosity function at z similar to 0.40 is obtained, which extends the current faint end by almost 1 dex, reaching minimal luminosities of log(10) L-lim = 38.5 erg s(-1) (or similar to 0.002 M-circle dot yr(-1)). The AGN contribution to the total H alpha luminosity is estimated. We find that no AGN should be expected below a luminosity of log(10) L = 38.6 erg s(-1). From the sample of non-AGN (presumably, pure SFG) at z similar to 0.40 we estimated a star formation rate density of rho(SFR) = 0.012 +/- 0.005 M-circle dot yr(-1) Mpc(-3)., This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under the grants AYA2013- 46724- P, AYA2014 58861-C3-1- P, AYA2014-58861-C3-2-P, AYA2014-58861-C3-3- P, AYA2016 -75808-R, AYA2016-75931-C2-2-P, AYA2017-88007-C3-1-P, and AYA2017 -88007-C3-2- P. Based on observations made with the Gran Telescopio Canarias installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in the island of La Palma. The authors thanks the anonymous referee for her/his feedback and suggestions.

This paper presents stellar mass functions and i-band luminosity functions for Sloan Digital Sky Survey (SDSS) galaxies at $i < 21$ using clustering redshifts, from which we also compute targeting completeness measurements for the Baryon Oscillation Spectroscopic Survey (BOSS). Clustering redshifts is a method of obtaining the redshift distribution of a sample of galaxies with only photometric information by measuring the angular crosscorrelation with a spectroscopic sample in different redshift bins. We construct a spectroscopic sample containing data from the BOSS + eBOSS surveys, allowing us to recover redshift distributions from photometric data out to $z\simeq 2.5$. We produce k-corrected i-band luminosity functions and stellar mass functions by applying clustering redshifts to SDSS DR8 galaxies in small bins of colour and magnitude. There is little evolution in the mass function between $0.2 < z < 0.8$, implying the most massive galaxies form most of their mass before $z = 0.8$. These mass functions are used to produce stellar mass completeness estimates for the Baryon Oscillation Spectroscopic Survey (BOSS), giving a stellar mass completeness of $80\%$ above $M_{\star} > 10^{11.4}$ between $0.2 < z < 0.7$, with completeness falling significantly at redshifts higher than 0.7, and at lower masses. Large photometric datasets will be available in the near future (DECaLS, DES, Euclid), so this, and similar techniques will become increasingly useful in order to fully utilise this data., 19 pages, 15 figures

We use the results from the ALMA large program ASPECS, the spectroscopic survey in the Hubble Ultra Deep Field (HUDF), to constrain CO luminosity functions of galaxies and the resulting redshift evolution of $\rho$(H$_2$). The broad frequency range covered enables us to identify CO emission lines of different rotational transitions in the HUDF at $z>1$. We find strong evidence that the CO luminosity function evolves with redshift, with the knee of the CO luminosity function decreasing in luminosity by an order of magnitude from $\sim$2 to the local universe. Based on Schechter fits, we estimate that our observations recover the majority (up to $\sim$90%, depending on the assumptions on the faint end) of the total cosmic CO luminosity at $z$=1.0-3.1. After correcting for CO excitation, and adopting a Galactic CO-to-H$_2$ conversion factor, we constrain the evolution of the cosmic molecular gas density $\rho$(H$_2$): this cosmic gas density peaks at $z\sim1.5$ and drops by factor of $6.5_{-1.4}^{+1.8}$ to the value measured locally. The observed evolution in $\rho$(H$_2$) therefore closely matches the evolution of the cosmic star formation rate density $\rho_{\rm SFR}$. We verify the robustness of our result with respect to assumptions on source inclusion and/or CO excitation. As the cosmic star formation history can be expressed as the product of the star formation efficiency and the cosmic density of molecular gas, the similar evolution of $\rho$(H$_2$) and $\rho_{\rm SFR}$ leaves only little room for a significant evolution of the average star formation efficiency in galaxies since $z\sim 3$ (85% of cosmic history)., Comment: 22 pages, 11 figures. Paper re-submitted to ApJ after addressing the first round of comments by the referee

We estimate the cosmic number density of the recently identified class of HI-bearing ultra-diffuse sources (HUDs) based on the completeness limits of the ALFALFA survey. These objects have HI masses approximately in the range 8.5 < logM/M < 9.5, average r-band surface brightnesses fainter than 24 mag arcsec, half-light radii greater than 1.5 kpc, and are separated from neighbours by at least 350 kpc. In this work we demonstrate that they contribute at most ∼6% of the population of HI-bearing dwarfs detected by ALFALFA (with similar HI masses), have a total cosmic number density of (1.5 ± 0.6) × 10 Mpc, and an HI mass density of (6.0 ± 0.8) × 10 M Mpc. We estimate that this is similar to the total cosmic number density of ultra-diffuse galaxies (UDGs) in groups and clusters, and conclude that the relation between the number of UDGs hosted in a halo and the halo mass must have a break below M ∼ 10 M in order to account for the abundance of HUDs in the field. The distribution of the velocity widths of HUDs rises steeply towards low values, indicating a preference for slow rotation rates compared to the global HI-rich dwarf population. These objects were already included in previous measurements of the HI mass function, but have been absent from measurements of the galaxy stellar mass function owing to their low surface brightness. However, we estimate that due to their low number density the inclusion of HUDs would constitute a correction of less than 1%. Comparison with the Santa Cruz semi-analytic model shows that it produces HI-rich central UDGs that have similar colours to HUDs, but that these UDGs are currently produced in a much greater number. While previous results from this sample have favoured formation scenarios where HUDs form in high spin-parameter halos, comparisons with recent results which invoke that formation mechanism reveal that this model produces an order of magnitude more field UDGs than we observe in the HUD population, and these have an occurrence rate (relative to other dwarfs) that is approximately double what we observe. In addition, the colours of HUDs are bluer than predicted, although we suspect this is due to a systematic problem in reproducing the star formation histories of low-mass galaxies rather than being specific to the ultra-diffuse nature of these sources.© ESO 2018., MGJ acknowledges support from the grant AYA2015-65973-C3-1-R (MINECO/FEDER, UE).

We present spectroscopy of emission lines for 81 Seyfert 1 and 104 Seyfert 2 galaxies in the IRAS 12$\mu$m galaxy sample. We analyzed the emission-line luminosity functions, reddening, and other gas diagnostics. The narrow-line regions (NLR) of Sy1 and 2 galaxies do not significantly differ from each other in most of these diagnostics. Combining the H$\alpha$/H$\beta$ ratio with a new reddening indicator-the [SII]6720/[OII]3727 ratio, we find the average $E(B-V)=0.49\pm0.35$ for Sy1s and $0.52\pm0.26$ for Sy2s. The NLR of Sy1 galaxies has only marginally higher ionization than the Sy2s. Our sample includes 22 Sy1.9s and 1.8s. In their narrow lines, these low-luminosity Seyferts are more similar to the Sy2s than the Sy1s. We construct a BPT diagram, and include the Sy1.8s and 1.9s. They overlap the region occupied by the Sy2s. The C IV equivalent width correlates more strongly with [O III]/H$\beta$ than with UV luminosity. The Sy1 and Sy2 luminosity functions of [OII]3727 and [OIII]5007 are indistinguishable. Unlike the LF's of Seyfert galaxies measured by SDSS, ours are nearly flat at low L. The larger number of faint Sloan "AGN" is attributable to their inclusion of weakly emitting LINERs and H II+AGN "composite" nuclei, which do not meet our classification criteria for Seyferts. An Appendix investigates which emission line luminosities provide the most reliable measures of the total non-stellar luminosity. The hard X-ray or near-ultraviolet continuum luminosity can be crudely predicted from either the [O III]5007 luminosity, or the combination of [O III]+H$\beta$, or [N II]+H$\alpha$ lines, with a scatter of $\pm\,4$ times for the Sy1s and $\pm\,10$ times for the Sy2s. The latter two hybrid (NLR+BLR) indicators have the advantage of predicting the same HX luminosity independent of Seyfert type.

We present the dust mass function (DMF) of 15,750 galaxies with redshift $z< 0.1$, drawn from the overlapping area of the GAMA and {\it H-}ATLAS surveys. The DMF is derived using the density corrected $V_{\rm max}$ method, where we estimate $V_{\rm max}$ using: (i) the normal photometric selection limit ($pV_{\rm max}$) and (ii) a bivariate brightness distribution (BBD) technique, which accounts for two selection effects. We fit the data with a Schechter function, and find $M^{*}=(4.65\pm0.18)\times 10^{7}\,h^2_{70}\, M_{\odot}$, $\alpha=(1.22\pm 0.01)$, $\phi^{*}=(6.26\pm 0.28)\times 10^{-3}\,h^3_{70}\,\rm Mpc^{-3}\,dex^{-1}$. The resulting dust mass density parameter integrated down to $10^4\,M_{\odot}$ is $\Omega_{\rm d}=(1.11 \pm0.02)\times 10^{-6}$ which implies the mass fraction of baryons in dust is $f_{m_b}=(2.40\pm0.04)\times 10^{-5}$; cosmic variance adds an extra 7-17\,per\,cent uncertainty to the quoted statistical errors. Our measurements have fewer galaxies with high dust mass than predicted by semi-analytic models. This is because the models include too much dust in high stellar mass galaxies. Conversely, our measurements find more galaxies with high dust mass than predicted by hydrodynamical cosmological simulations. This is likely to be from the long timescales for grain growth assumed in the models. We calculate DMFs split by galaxy type and find dust mass densities of $\Omega_{\rm d}=(0.88\pm0.03)\times 10^{-6}$ and $\Omega_{\rm d}=(0.060\pm0.005)\times 10^{-6}$ for late-types and early-types respectively. Comparing to the equivalent galaxy stellar mass functions (GSMF) we find that the DMF for late-types is well matched by the GMSF scaled by $(8.07\pm0.35) \times 10^{-4}$., Comment: 25 Pages, 18 Figures. Submitted December 2017

Lopez-Sanjuan, C. et. al., Aims. Our goal is to study the evolution of the B-band luminosity function (LF) since z ∼ 1 using ALHAMBRA data. Methods. We used the photometric redshift and the I-band selection magnitude probability distribution functions (PDFs) of those ALHAMBRA galaxies with I ≤ 24 mag to compute the posterior LF. We statistically studied quiescent and star-forming galaxies using the template information encoded in the PDFs. The LF covariance matrix in redshift - magnitude - galaxy type space was computed, including the cosmic variance. That was estimated from the intrinsic dispersion of the LF measurements in the 48 ALHAMBRA sub-fields. The uncertainty due to the photometric redshift prior is also included in our analysis. Results. We modelled the LF with a redshift-dependent Schechter function affected by the same selection effects than the data. The measured ALHAMBRA LF at 0.2 ≤ z < 1 and the evolving Schechter parameters both for quiescent and star-forming galaxies agree with previous results in the literature. The estimated redshift evolution of M∗B ∝ Qz is QSF = -1.03±0.08 and QQ = -0.80±0.08, and of log10φ∗ ∝ Pz is PSF = -0.01±0.03 and PQ = -0.41 ± 0.05. The measured faint-end slopes are αSF = -1.29 ± 0.02 and αQ = -0.53 ± 0.04. We find a significant population of faint quiescent galaxies with MB ≳ -18, modelled by a second Schechter function with slope β = -1.31 ± 0.11. Conclusions. We present a robust methodology to compute LFs using multi-filter photometric data. The application to ALHAMBRA shows a factor 2.55 ± 0.14 decrease in the luminosity density jB of star-forming galaxies, and a factor 1.25 ± 0.16 increase in the jB of quiescent ones since z = 1, confirming the continuous build-up of the quiescent population with cosmic time. The contribution of the faint quiescent population to jB increases from 3% at z = 1 to 6% at z = 0. The developed methodology will be applied to future multi-filter surveys such as J-PAS. © 2017 ESO., This work has been mainly funded by the FITE (Fondos de Inversiones de Teruel) and the projects AYA2015-66211-C2-1, AYA2012-30789, AYA200614056, and CSD2007-00060. We also acknowledge support from the Spanish Ministry for Economy and Competitiveness and FEDER funds through grants AYA2010-15081, AYA2010-15169, AYA2010-22111-C03-01, AYA201022111- C03-02, AYA2011-29517-C03-01, AYA2012-39620, AYA2013-40611P, AYA2013-42227-P, AYA2013-43188-P, AYA2013-48623-C2-1, AYA201348623- C2-2, ESP2013-48274, AYA2014-58861-C3-1, Aragon Government Research Group E103, Generalitat Valenciana projects Prometeo 2009/064 and PROMETEOII/2014/060, Junta de Andalucia grants TIC114, JA2828, P10FQM-6444, and Generalitat de Catalunya project SGR-1398. E. T. acknowledges the support by the ETAg grants IUT26-2, IUT40-2, and by the European Regional Development Fund (TK133). A. M. acknowledges the financial support of the Brazilian funding agency FAPESP (Post-doc fellowship - process number 2014/11806-9). B. A. has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 656354.

We have developed an analytical method based on forward-modeling techniques to characterize the high-mass end of the red sequence (RS) galaxy population at redshift $z\sim0.55$, from the DR10 BOSS CMASS spectroscopic sample, which comprises $\sim600,000$ galaxies. The method, which follows an unbinned maximum likelihood approach, allows the deconvolution of the intrinsic CMASS colour-colour-magnitude distributions from photometric errors and selection effects. This procedure requires modeling the covariance matrix for the i-band magnitude, g-r colour and r-i colour using Stripe 82 multi-epoch data. Our results indicate that the error-deconvolved intrinsic RS distribution is consistent, within the photometric uncertainties, with a single point ($, Comment: 27 pages, 20 figures, accepted for publication in MNRAS

The fraction of galaxies bound in groups in the nearby Universe is high (50% at z~0). Systematic studies of galaxy properties in groups are important in order to improve our understanding of the evolution of galaxies and of the physical phenomena occurring within this environment. We have built a complete spectrophotometric sample of galaxies within X-ray detected, optically spectroscopically confirmed groups and clusters (G&C), covering a wide range of halo masses at z, 20 pages, 18 figures, 6 tables, accepted for publication in A&A

We derive NUV luminosity functions for 6471 NUV detected galaxies in 28 $0.02 < z < 0.08$ clusters and consider their dependence on cluster properties. We consider optically red and blue galaxies and explore how their NUV LFs vary in several cluster subsamples, selected to best show the influence of environment. Our composite LF is well fit by the Schechter form with $M^*_{NUV}=-18.98 \pm 0.07$ and $\alpha=-1.87 \pm 0.03$ in good agreement with values for the Coma centre and the Shapley supercluster, but with a steeper slope and brighter $L^*$ than in Virgo. The steep slope is due to the contribution of massive quiescent galaxies that are faint in the NUV. There are significant differences in the NUV LFs for clusters having low and high X-ray luminosities and for sparse and dense clusters, though none are particularly well fitted by the Schechter form, making a physical interpretation of the parameters difficult. When splitting clusters into two subsamples by X-ray luminosity, the ratio of low to high NUV luminosity galaxies is higher in the high X-ray luminosity subsample (i.e the luminosity function is steeper across the sampled luminosity range). In subsamples split by surface density, when characterised by Schechter functions the dense clusters have an $M^*$ about a magnitude fainter than that of the sparse clusters and $\alpha$ is steeper ($-1.9$ vs. $-1.6$ respectively). The differences in the data appear to be driven by changes in the LF of blue (star-forming) galaxies. This appears to be related to interactions with the cluster gas [abridged], Comment: Accepted A&A

We report an expanded sample of visual morphological classifications from the Galaxy and Mass Assembly (GAMA) survey phase two, which now includes 7,556 objects (previously 3,727 in phase one). We define a local (z, 13 pages, 9 figures (high-resolution figures available in journal version), MNRAS accepted

Motivated by recent progress in studies of the high-$z$ Universe, we build a new model for the global 21-cm signal that is explicitly calibrated to measurements of the galaxy luminosity function (LF) and further tuned to match the Thomson scattering optical depth of the cosmic microwave background, $\tau_e$. Assuming that the $z \lesssim 8$ galaxy population can be smoothly extrapolated to higher redshifts, the recent decline in best-fit values of $\tau_e$ and the inefficient heating induced by X-ray binaries (HMXBs; the presumptive sources of the X-ray background at high-$z$) imply that the entirety of cosmic reionization and reheating occurs at redshifts $z \lesssim 12$. In contrast to past global 21-cm models, whose $z \sim 20$ ($\nu \sim 70$ MHz) absorption features and strong $\sim 25$ mK emission features were driven largely by the assumption of efficient early star-formation and X-ray heating, our new fiducial model peaks in absorption at $\nu \sim 110$ MHz at a depth of $\sim -160$ mK and has a negligible emission component. As a result, a strong emission signal would provide convincing evidence that HMXBs are not the only drivers of cosmic reheating. Shallow absorption troughs should accompany strong heating scenarios, but could also be caused by a low escape fraction of Lyman-Werner photons. Generating signals with troughs at $\nu \lesssim 95$ MHz requires a floor in the star-formation efficiency in halos below $\sim 10^{9} M_{\odot}$, which is equivalent to steepening the faint-end of the galaxy LF. These findings demonstrate that the global 21-cm signal is a powerful complement to current and future galaxy surveys and efforts to better understand the interstellar medium in high-$z$ galaxies., Comment: 17 pages, 9 figures, in press

We present the evolution in the number density and stellar mass functions of photometrically selected post-starburst galaxies in the UKIDSS Deep Survey (UDS), with redshifts of 0.510. We find that this transitionary species of galaxy is rare at all redshifts, contributing ~5% of the total population at z~2, to 2 they are exclusively massive galaxies that have formed the bulk of their stars during a rapid assembly period, followed by complete quenching of further star formation, (2) at z, Comment: 14 pages, 7 figures, accepted by MNRAS

We build on a recent photometric decomposition analysis of 7506 Galaxy and Mass Assembly (GAMA) survey galaxies to derive stellar mass function fits to individual spheroid and disk component populations down to a lower mass limit of log(M_*/M_sun)= 8. We find that the spheroid/disk mass distributions for individual galaxy morphological types are well described by single Schechter function forms. We derive estimates of the total stellar mass densities in spheroids (rho_spheroid = 1.24+/-0.49 * 10^8 M_sun Mpc^-3 h_0.7) and disks (rho_disk = 1.20+/-0.45 * 10^8 M_sun Mpc^-3 h_0.7), which translates to approximately 50% of the local stellar mass density in spheroids and 48% in disks. The remaining stellar mass is found in the dwarf "little blue spheroid" class, which is not obviously similar in structure to either classical spheroid or disk populations. We also examine the variation of component mass ratios across galaxy mass and group halo mass regimes, finding the transition from spheroid to disk mass dominance occurs near galaxy stellar mass ~10^11 M_sun and group halo mass ~10^12.5 M_sun/h. We further quantify the variation in spheroid-to-total mass ratio with group halo mass for central and satellite populations as well as the radial variation of this ratio within groups., Comment: 14 pages; 10 figures; MNRAS accepted

We have previously calculated the intergalactic background light (IBL) as a function of redshift in the far ultraviolet to near infrared range, based purely on data from deep galaxy surveys. Here we utilize similar methods to determine the mid- and far infrared IBL out to a wavelength of 850 microns. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. By also including the effect of the 2.7 K cosmic background photons, we determine 68% confidence upper and lower limits on the opacity of the universe to gamma-rays up to PeV energies. Our direct results on the IBL are consistent with those from complimentary gamma-ray analyses using observations from the Fermi $\gamma$-ray space telescope and the H.E.S.S. air Cherenkov telescope. Thus, we find no evidence of previously suggested processes for the modification of gamma-ray spectra other than that of absorption by pair production alone., Comment: 33 pages, 11 figures, replacement matches article published in ApJ 827:6 (2016)

© 2015 The Authors. We constrain the evolution of the galaxy stellar mass function from 2 2 × 105M⊙at z = 0). The most recent studies from ZFOURGE and CANDELS also suggest flatter faint end slopes that are consistent with our results, but with a lower degree of precision. This work illustrates the strong connections between low and high-z observations when viewed through the lens of lambda cold dark matter numerical simulations.

JL acknowledges support from the Science and Technology Facilities Council (grant number ST/I000976/1) and illuminating discussions with Shaun Cole. PN acknowledges the support of the Royal Society through the award of a University Research Fellowship, the European Research Council, through receipt of a Starting Grant (DEGAS-259586) and the Science and Technology Facilities Council (ST/L00075X/1). We describe modifications to the joint stepwise maximum-likelihood method of Cole in order to simultaneously fit the Galaxy and Mass Assembly II galaxy luminosity function (LF), corrected for radial density variations, and its evolution with redshift. The whole sample is reasonably well fitted with luminosity (Qe) and density (Pe) evolution parameters Qe, Pe ≈ 1.0, 1.0 but with significant degeneracies characterized by Qe ≈ 1.4 − 0.4Pe. Blue galaxies exhibit larger luminosity density evolution than red galaxies, as expected. We present the evolution-corrected r-band LF for the whole sample and for blue and red subsamples, using both Petrosian and Sérsic magnitudes. Petrosian magnitudes miss a substantial fraction of the flux of de Vaucouleurs profile galaxies: the Sérsic LF is substantially higher than the Petrosian LF at the bright end. Publisher PDF

Astronomy and Astrophysics 575 (2015): A40 reproduced with permission from Astronomy & Astrophysics, © ESO, We present the [OII] (λλ3729,3726) luminosity function measured in the redshift range 0.1, J.C. acknowledges financial support from MINECO (Spain) under project number AYA2012-31101. J.R. acknowledges support from the ERC starting grant CALENDS. J.P.K. and T.D. acknowledge support from the LIDA ERC advanced grant. Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The BOSS French Participation Group is supported by Agence Nationale de la Recherche under grant ANR-08-BLAN-0222. This equipment was funded by BIS National Einfrastructure capital grant ST/K00042X/1, STFC capital grant ST/H008519/1, and STFC DiRAC Operations grant ST/K003267/1 and Durham University. DiRAC is part of the National E-Infrastructure. V.G.P. acknowledges support from a European Research Council Starting Grant (DEGAS-259586) and the Science and Technology Facilities Council (grant number ST/F001166/1)

International audience; The relation between the stellar mass (M⋆) and the star formation rate (SFR) characterizes how the instantaneous star formation is determined by the galaxy past star formation history and by the growth of the dark matter structures. We deconstruct the M⋆-SFR plane by measuring the specific SFR functions in several stellar mass bins from z = 0.2 out to z = 1.4 (specific SFR = SFR/M⋆, noted sSFR). Our analysis is primary based on a 24 μm selected catalogue combining the COSMOS and GOODS surveys. We estimate the SFR by combining mid- and far-infrared data for 20500 galaxies. The sSFR functions are derived in four stellar mass bins within the range 9.5 < log (M⋆ /M⊙) < 11.5. First, we demonstrate the importance of taking into account selection effects when studying the M⋆-SFR relation. Secondly, we find a mass-dependent evolution of the median sSFR with redshift varying as sSFR ∝ (1 + z)b, with b increasing from b = 2.88±0.12 to b = 3.78± 0.60 between M⋆ = 109.75 M⊙ and M⋆ = 1011.1 M⊙, respectively. At low masses, this evolution is consistent with the cosmological accretion rate and predictions from semi-analytical models (SAM). This agreement breaks down for more massive galaxies showing the need for a more comprehensive description of the star formation history in massive galaxies. Third, we obtain that the shape of the sSFR function is invariant with time at z< 1.4 but depends on the mass. We observe a broadening of the sSFR function ranging from 0.28 dex at M⋆ = 109.75 M⊙ to 0.46 dex at M⋆ = 1011.1 M⊙. Such increase in the intrinsic scatter of the M⋆-SFR relation suggests an increasing diversity ofstar formation histories (SFHs) as the stellar mass increases. Finally, we find a gradual decline of the sSFR with stellar mass as log 10(sSFR) ∝ −0.17M⋆. We discuss the numerous physical processes, as gas exhaustion in hot gas halos or secular evolution, which can gradually reduce the sSFR and increase the SFH diversity.

In nature we observe galaxy aggregations that span a wide range of magnitude gaps between the two first-ranked galaxies of a system ($\Delta m_{12}$). There are systems with gaps close to zero (e.g., the Coma cluster), and at the other extreme of the distribution, the largest gaps are found among the so-called fossil systems. Fossil and non-fossil systems could have different galaxy populations that should be reflected in their luminosity functions. In this work we study, for the first time, the dependence of the luminosity function parameters on $\Delta m_{12}$ using data obtained by the fossil group origins (FOGO) project. We constructed a hybrid luminosity function for 102 groups and clusters at $z \le 0.25$. We stacked all the individual luminosity functions, dividing them into bins of $\Delta m_{12}$, and studied their best-fit Schechter parameters. We additionally computed a relative luminosity function, expressed as a function of the central galaxy luminosity, which boosts our capacity to detect differences, especially at the bright end. We find trends as a function of $\Delta m_{12}$ at both the bright and faint ends of the luminosity function. In particular, at the bright end, the larger the magnitude gap, the fainter the characteristic magnitude $M^\ast$. We also find differences at the faint end. In this region, the larger the gap, the flatter the faint-end slope $\alpha$. The differences found at the bright end support a dissipationless, dynamical friction-driven merging model for the growth of the central galaxy in group- and cluster-sized halos. The differences in the faint end cannot be explained by this mechanism. Other processes, such as enhanced tidal disruption due to early infall and/or prevalence of eccentric orbits, may play a role. However, a larger sample of systems with $\Delta m_{12} > 1.5$ is needed to establish the differences at the faint end., Comment: 11 pages, 10 figures, accepted for publication in A&A

We present new measurements of the evolution of the X-ray luminosity functions (XLFs) of unabsorbed and absorbed Active Galactic Nuclei (AGNs) out to z~5. We construct samples containing 2957 sources detected at hard (2-7 keV) X-ray energies and 4351 sources detected at soft (0.5-2 keV) energies from a compilation of Chandra surveys supplemented by wide-area surveys from ASCA} and ROSAT. We consider the hard and soft X-ray samples separately and find that the XLF based on either (initially neglecting absorption effects) is best described by a new flexible model parametrization where the break luminosity, normalization and faint-end slope all evolve with redshift. We then incorporate absorption effects, separately modelling the evolution of the XLFs of unabsorbed ($20, Comment: 36 pages, 20 figures, 11 tables. A casual reader is directed to figures 7, 8, 9 and 20. Updated to version accepted for publication in MNRAS

We derive the CO luminosity function (LF) for different rotational transitions (i.e. (1-0), (3-2), (5-4)) starting from the Herschel LF by Gruppioni et al. and using appropriate $L'_{\rm CO} - L_{\rm IR}$ conversions for different galaxy classes. Our predicted LFs fit the data so far available at $z\approx0$ and $2$. We compare our results with those obtained by semi-analytical models (SAMs): while we find a good agreement over the whole range of luminosities at $z\approx0$, at $z\approx1$ and $z\approx2$ the tension between our LFs and SAMs in the faint and bright ends increases. We finally discuss the contribution of luminous AGN ($L_{X}>10^{44}\,\rm{erg\,s^{-1}}$) to the bright end of the CO LF concluding that they are too rare to reproduce the actual CO luminosity function at $z\approx2$., 5 pages, 3 figures, accepted for publication in MNRAS Letters

We obtain a sample of 87 radio-loud quasi-stellar objects (QSOs) in the redshift range 3.6 1 mJy) with star-like objects having r < 20.2 in Sloan Digital Sky Survey (SDSS) Data Release 7. Of these 87 QSOs, 80 are spectroscopically classified in previous work (mainly SDSS), and form the training set for a search for additional such sources. We apply our selection to 2916 FIRST-DR7 pairs and find 15 likely candidates. Seven of these are confirmed as high-redshift quasars, bringing the total to 87. The candidates were selected using a neural-network, which yields 97 per cent completeness (fraction of actual high-z QSOs selected as such) and an efficiency (fraction of candidates which are high-z QSOs) in the range of 47-60 per cent. We use this sample to estimate the binned optical luminosity function (LF) of radio-loud QSOs at z ∼ 4, and also the LF of the total QSO population and its comoving density. Our results suggest that the radio-loud fraction at high z is similar to that at low z and that other authors may be underestimating the fraction at high z. Finally, we determine the slope of the optical LF and obtain results consistent with previous studies of radio-loud QSOs and of the whole population of QSOs. The evolution of the LF with redshift was for many years interpreted as a flattening of the bright-end slope, but has recently been re-interpreted as strong evolution of the break luminosity for high-z QSOs, and our results, for the radio-loud population, are consistent with this., This work has been funded by the Spanish Ministerio de Ciencia e Innovacion (MICINN) under project AYA2011-29517-C03-02.

© ESO 2015. Context. The discovery of new galaxy clusters is important for two reasons. First, clusters are interesting per se, since their detailed analysis allows us to understand how galaxies form and evolve in various environments and second, they play an important part in cosmology because their number as a function of redshift gives constraints on cosmological parameters. Aims. We have searched for galaxy clusters in the Stripe 82 region of the Sloan Digital Sky Survey, and analysed various properties of the cluster galaxies. Methods. Based on a recent photometric redshift (hereafter photo-z) galaxy catalogue, we built a cluster catalogue by applying the Adami & MAzure Cluster FInder (AMACFI). Extensive tests were made to fine-tune the AMACFI parameters and make the cluster detection as reliable as possible. The same method was applied to the Millennium simulation to estimate our detection efficiency and the approximate masses of the detected clusters. Considering all the cluster galaxies (i.e. within a 1 Mpc radius of the cluster to which they belong and with a photo-z diering by less than ±0.05 from that of the cluster), we stacked clusters in various redshift bins to derive colour-magnitude diagrams and galaxy luminosity functions (GLFs). For each galaxy brighter than Mr < - 19.0, we computed the disk and spheroid components by applying SExtractor, and by stacking clusters we determined how the disk-to-spheroid flux ratio varies with cluster redshift and mass. Results. We detected 3663 clusters in the redshift range 0.15 ≤ z ≤ 0.70, with estimated mean masses between ∼1013 and a few 1014 M⊙. We cross-matched our catalogue of candidate clusters with various catalogues extracted from optical and/or X-ray data. The percentages of redetected clusters are at most 40% because in all cases we detect relatively massive clusters, while other authors detect less massive structures. By stacking the cluster galaxies in various redshift bins, we find a clear red sequence in the (ǵ - ŕ) versus ŕ colour-magnitude diagrams, and the GLFs are typical of clusters, though with a possible contamination from field galaxies. The morphological analysis of the cluster galaxies shows that the fraction of late-type to early-type galaxies shows an increase with redshift (particularly in 9σ clusters) and a decrease with detection level, i.e. cluster mass. Conclusions. From the properties of the cluster galaxies, the majority of the candidate clusters detected here seem to be real clusters with typical cluster properties., F.D. acknowledges long-term support from CNES. I.M. acknowledges financial support from the Spanish grants AYA2010-15169 and AYA2013-42227-P and from the Junta de Andalucia through TIC-114 and the Excellence Project P08-TIC-03531. A.T. acknowledges the support and the hospitality of IAP/CNRS for two one month visits. We are grateful to Andrea Biviano for giving us his IDL program to fit GLFs with a Schechter function and to Alberto Cappi for discussions. We thank the six high school students M.A. Garcia Valverde, B. Hernandez Ramos, J. Leon Lovell, L. Martinez Sanchez de Lara, J. Rodriguez Zamorano and L. Vallecillos Azor for their careful eye classification of about 1000 galaxies. Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the US Department of Energy Office of Science. The SDSS-III web site is http://www.sdss3.org/. SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University.

We present measurements of the clustering of galaxies as a function of their stellar mass in the Baryon Oscillation Spectroscopic Survey. We compare the clustering of samples using 12 different methods for estimating stellar mass, isolating the method that has the smallest scatter at fixed halo mass. In this test, the stellar mass estimate with the smallest errors yields the highest amplitude of clustering at fixed number density. We find that the PCA stellar masses of Chen etal (2012) clearly have the tightest correlation with halo mass. The PCA masses use the full galaxy spectrum, differentiating them from other estimates that only use optical photometric information. Using the PCA masses, we measure the large-scale bias as a function of Mgal for galaxies with logMgal>=11.4, correcting for incompleteness at the low-mass end of our measurements. Using the abundance-matching ansatz to connect dark matter halo mass to stellar mass, we construct theoretical models of b(Mgal) that match the same stellar mass function but have different amounts of scatter in stellar mass at fixed halo mass, sigma_logM. Using this approach, we find sigma_logM=0.18^{+0.01}_{-0.02}. This value includes both intrinsic scatter as well as random errors in the stellar masses. To partially remove the latter, we use repeated spectra to estimate statistical errors on the stellar masses, yielding an upper limit to the intrinsic scatter of 0.16 dex., 11 pages, 10 figures, submitted to ApJ

We use 80922 galaxies in the Galaxy And Mass Assembly (GAMA) survey to measure the galaxy luminosity function (LF) in different environments over the redshift range 0.04, Comment: 23 pages, 17 figures. Accepted for publication in MNRAS

The galaxy stellar mass function (GSMF) at high-z provides key information on star-formation history and mass assembly in the young Universe. We aimed to use the unique combination of deep optical/NIR/MIR imaging provided by HST, Spitzer and the VLT in the CANDELS-UDS, GOODS-South, and HUDF fields to determine the GSMF over the redshift range 3.54. These results confirm the unique synergy of the CANDELS+HUDF, HUGS, and SEDS surveys for the discovery and study of moderate/low-mass galaxies at high redshifts., Comment: 26 pages, 23 figures. Accepted for publication on A&A

We use a highly complete subset of the GAMA-II redshift sample to fully describe the stellar mass dependence of close-pairs and mergers between 10^8 Msun and 10^12 Msun. Using the analytic form of this fit we investigate the total stellar mass accreting onto more massive galaxies across all mass ratios. Depending on how conservatively we select our robust merging systems, the fraction of mass merging onto more massive companions is 2.0%-5.6%. Using the GAMA-II data we see no significant evidence for a change in the close-pair fraction between redshift $z = 0.05-0.2$. However, we find a systematically higher fraction of galaxies in similar mass close-pairs compared to published results over a similar redshift baseline. Using a compendium of data and the function $\gamma_M =A(1+z)m$ to predict the major close-pair fraction, we find fitting parameters of $A = 0.021 \pm 0.001$ and $m = 1.53 \pm 0.08$, which represents a higher low-redshift normalisation and shallower power-law slope than recent literature values. We find that the relative importance of in-situ star-formation versus galaxy merging is inversely correlated, with star-formation dominating the addition of stellar material below Mstar and merger accretion events dominating beyond Mstar. We find mergers have a measurable impact on the whole extent of the GSMF, manifest as a deepening of the dip in the GSMF over the next Gyr and an increase in Mstar by as much as 0.01-0.05 dex., Comment: Accepted for publication in MNRAS: 25 Pages, 21 Figures, 3 Tables

We measure the mass functions for generically red and blue galaxies, using a z < 0.12 sample of log M* > 8.7 field galaxies from the Galaxy And Mass Assembly (GAMA) survey. Our motivation is that, as we show, the dominant uncertainty in existing measurements stems from how 'red' and 'blue' galaxies have been selected/defined. Accordingly, we model our data as two naturally overlapping populations, each with their own mass function and colour-mass relation, which enables us characterise the two populations without having to specify a priori which galaxies are 'red' and 'blue'. Our results then provide the means to derive objective operational definitions for the terms 'red' and 'blue', which are based on the phenomenology of the colour-mass diagrams. Informed by this descriptive modelling, we show that: 1.) after accounting for dust, the stellar colours of 'blue' galaxies do not depend strongly on mass; 2.) the tight, flat 'dead sequence' does not extend much below log M* ~ 10.5; instead, 3.) the stellar colours of 'red' galaxies vary rather strongly with mass, such that lower mass 'red' galaxies have bluer stellar populations; 4.) below log M* ~ 9.3, the 'red' population dissolves into obscurity, and it becomes problematic to talk about two distinct populations; as a consequence, 5.) it is hard to meaningfully constrain the shape, including the possibility of an upturn, of the 'red' galaxy mass function below log M* ~ 9. Points 1-4 provide meaningful targets for models of galaxy formation and evolution to aim for., Accepted by MNRAS - 16 figures, 42 pages including 1 appendix - all results will be made available online via MNRAS, source code can be provided on request

We present a new deep determination of the spectroscopic LF within the virial radius of the nearby and massive Abell\,85 (A85) cluster down to the dwarf regime (M* + 6) using VLT/VIMOS spectra for $\sim 2000$ galaxies with m$_r \leq 21$ mag and $\langle \mu_{e,r} \rangle \leq 24$ mag arcsec$^{-2}$. The resulting LF from 438 cluster members is best modelled by a double Schechter function due to the presence of a statistically significant upturn at the faint-end. The amplitude of this upturn ($\alpha_{f} = -1.58^{+0.19}_{-0.15}$), however, is much smaller than that of the SDSS composite photometric cluster LF by Popesso et al. 2006, $\alpha_{f} \sim$ -2. The faint-end slope of the LF in A85 is consistent, within the uncertainties, with that of the field. The red galaxy population dominates the LF at low luminosities, and is the main responsible for the upturn. The fact that the slopes of the spectroscopic LFs in the field and in a cluster as massive as A85 are similar suggests that the cluster environment does not play a major role in determining the abundance of low-mass galaxies., Comment: 6 pages, 4 figures, accepted at MNRAS letter

We report the morphological classification of 3727 galaxies from the Galaxy and Mass Assembly survey with M_r < -17.4 mag and in the redshift range 0.025 < z < 0.06 (2.1 x 10^5 Mpc^3 ) into E, S0-Sa, SB0-SBa, Sab-Scd, SBab-SBcd, Sd-Irr and little blue spheroid classes. Approximately 70% of galaxies in our sample are disk dominated systems, with the remaining ~30% spheroid dominated. We establish the robustness of our classifications, and use them to derive morphological-type luminosity functions and luminosity densities in the ugrizYJHK passbands, improving on prior studies that split by global colour or light profile shape alone. We find that the total galaxy luminosity function is best described by a double-Schechter function while the constituent morphological-type luminosity functions are well described by a single-Schechter function. These data are also used to derive the star-formation rate densities for each Hubble class, and the attenuated and unattenuated (corrected for dust) cosmic spectral energy distributions, i.e., the instantaneous energy production budget. While the observed optical/near-IR energy budget is dominated 58:42 by galaxies with a significant spheroidal component, the actual energy production rate is reversed, i.e., the combined disk dominated populations generate ~1.3x as much energy as the spheroid dominated populations. On the grandest scale, this implies that chemical evolution in the local Universe is currently confined to mid-type spiral classes like our Milky Way., 27 pages, 22 figures, accepted for publication in MNRAS (see MNRAS version for high-quality figures)

We use the Herschel ATLAS (H-ATLAS) Phase I data to study the conditional luminosity function of far-IR (250 um) selected galaxies in optically-selected galaxy groups from the GAMA spectroscopic survey, as well as environmental effects on the far-IR-to-optical colour. We applied two methods, which gave consistent results for the far-IR conditional luminosity functions. The direct matching method matches H-ATLAS sources to GAMA/SDSS galaxies, then links the optical counterparts to GAMA groups. The stacking method counts the number of far-IR sources within the projected radii of GAMA groups, subtracting the local background. We investigated the dependence of the far-IR (250 um) luminosity function on group mass in the range 10d12 < M_h < 10d14Msun/h and on redshift in the range 0 < z < 0.4, using a sample of 3000 groups containing H-ATLAS sources with GAMA redshifts over an area of 126 sq. deg. We find that the characteristic 250 um luminosity, L^*(250), increases with group mass up to M_h ~ 10d13Msun/h, but is roughly constant above this, while it increases with redshift at high group masses, but less so at low masses. We also find that the group far-IR luminosity-to-mass ratio L(250)/M_h increases with redshift and is higher in low-mass groups. We estimate that around 70% of the 250 um luminosity density in the local universe is contributed by groups with M_h > 10d12Msun/h. We also find that the far-IR-to-optical colours of H-ATLAS galaxies are independent of group mass over the range 10d12 < M_h, 19 pages, accepted version (MNRAS)