ZFOURGE catalogue of AGN candidates: an enhancement of 160μm-derived star-formation rates in active galaxies to $z$ = 3.2
Michael J. Cowley, Lee R. Spitler, Kim-Vy H. Tran, Glen A. Rees, Ivo Labbé, Rebecca J. Allen, Gabriel B. Brammer, Karl Glazebrook, Andrew M. Hopkins, Stéphanie … 展开作者
Michael J. Cowley, Lee R. Spitler, Kim-Vy H. Tran, Glen A. Rees, Ivo Labbé, Rebecca J. Allen, Gabriel B. Brammer, Karl Glazebrook, Andrew M. Hopkins, Stéphanie Juneau, Glenn G. Kacprzak, James R. Mullaney, Themiya Nanayakkara, Casey Papovich, Ryan F. Quadri, Caroline M. S. Straatman, Adam R. Tomczak, Pieter G. van Dokkum
备注：
15 pages, 9 figures, Accepted for publication in MNRAS
We investigate active galactic nuclei (AGN) candidates within the FourStar Galaxy Evolution Survey (ZFOURGE) to determine the impact they have on star-formation in their host galaxies. We first identify a population of radio, X-ray, and infrared-selected AGN by cross-matching the deep $K_{s}$-band imaging of ZFOURGE with overlapping multi-wavelength data. From this, we construct a mass-complete (log(M$_{*}$/M$_{\odot}$) $\ge$ 9.75), AGN luminosity limited sample of 235 AGN hosts over z = 0.2 - 3.2. We compare the rest-frame U - V versus V - J (UVJ) colours and specific star-formation rates (sSFRs) of the AGN hosts to a mass-matched control sample of inactive (non-AGN) galaxies. UVJ diagnostics reveal AGN tend to be hosted in a lower fraction of quiescent galaxies and a higher fraction of dusty galaxies than the control sample. Using 160μm Herschel PACS data, we find the mean specific star-formation rate of AGN hosts to be elevated by 0.34$\pm$0.07 dex with respect to the control sample across all redshifts. This offset is primarily driven by infrared-selected AGN, where the mean sSFR is found to be elevated by as much as a factor of ~5. The remaining population, comprised predominantly of X-ray AGN hosts, is found mostly consistent with inactive galaxies, exhibiting only a marginal elevation. We discuss scenarios that may explain these findings and postulate that AGN are less likely to be a dominant mechanism for moderating galaxy growth via quenching than has previously been suggested.
In order to reproduce the high-mass end of the galaxy mass-distribution, some process must be responsible for the suppression of star-formation in the most massive of galaxies. Commonly Active Galactic Nuclei (AGN) are invoked to fulfil this role, but the exact means by which they do so is still the topic of much debate, with studies finding evidence for both the suppression and enhancement of star-formation in AGN hosts. Using the ZFOURGE and NMBS galaxy surveys, we investigate the host galaxy properties of a mass-limited (M$_{\odot}$ $\ge$ 10$^{10.5}$ M$_{\odot}$), high-luminosity (L$_{1.4}$…
The eJWST active galactic nucleus observation catalogue
Zentrum für Astronomie der Universität Heidelberg, Astronomisches Rechen-Institut（海德堡大学天文中心，天文计算研究所）；European Space Agency (ESA), European Space Astronomy Centre (ESAC)（欧洲空间局（ESA），欧洲空间天文中心（ESAC））；Telespazio UK S.L. for ESA, ESAC（为ESA和ESAC服务的泰雷兹英国有限公司）；Institut de Radioastronomie Millimétrique (IRAM)（毫米波射电天文学研究所（IRAM））；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心（CAB），西班牙国家科学研究委员会-国家航空航天技术研究所）
We present two catalogues of active galactic nucleus (AGN) candidates selected from the latest data of two all-sky surveys -- Data Release 2 (DR2) of the \emph{Gaia} mission and the unWISE catalogue of the \emph{Wide-field Infrared Survey Explorer} (\emph{WISE}). We train a random forest classifier to predict the probability of each source in the \emph{Gaia}-unWISE joint sample being an AGN, $P_{\rm RF}$, based on \emph{Gaia} astrometric and photometric measurements and unWISE photometry. The two catalogues, which we designate C75 and R85, are constructed by applying different $P_{\rm RF}$ thr…
We study the rest-frame ultra-violet sizes of massive (~0.8 x 10^11 M_Sun) galaxies at 3.4<z<4.2, selected from the FourStar Galaxy Evolution Survey (ZFOURGE), by fitting single Sersic profiles to HST/WFC3/F160W images from the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS). Massive quiescent galaxies are very compact, with a median circularized half-light radius r_e = 0.63 +/- 0.18 kpc. Removing 5/16 (31%) sources with signs of AGN activity does not change the result. Star-forming galaxies have r_e = 2.0 +/- 0.60 kpc, 3.2 +/- 1.3 x larger than quiescent galaxies. Qui…
We presented CAIXA, a Catalogue of AGN in the XMM-Newton Archive, in Bianchi et al. (2009). It consists of all the radio-quiet X-ray unobscured (N$_\mathrm{H}<2\times10^{22}$ cm$^{-2}$) active galactic nuclei (AGN) observed by XMM-Newton in targeted observations, whose data are public as of March 2007. With its 156 sources, this is the largest catalogue of high signal-to-noise X-ray spectra of AGN. All the EPIC pn spectra of the sources in CAIXA were extracted homogeneously and a baseline model was applied in order to derive their basic X-ray properties. These data are complemented by multiwav…
We have newly identified a substantial number of type 1 active galactic nuclei (AGN) featuring weak broad-line regions (BLRs) at z < 0.2 from detailed analysis of galaxy spectra in the Sloan Digital Sky Survey Data Release 7. These objects predominantly show a stellar continuum but also a broad H-alpha emission line, indicating the presence of a low-luminosity AGN oriented so that we are viewing the central engine directly without significant obscuration. These accreting black holes have previously eluded detection due to their weak nature. The new BLR AGNs we found increased the number of kno…
The goal of this work is to search for Active Galactic Nuclei (AGN) in the Galactic disc at very low latitudes with |b| $<$ 2$^\circ$. For this, we studied the five sources from the VVV near-infrared galaxy catalogue that have also WISE counterparts and present variability in the VIrac VAriable Classification Ensemble (VIVACE) catalogue. In the near-infrared colour-colour diagrams, these objects have in general redder colours compared to the rest of the sources in the field. In the mid-infrared ones, they are located in the AGN region, however there is a source that presents the highest inters…
We present a catalogue of local ($z<0.1$) galaxies that contain faint AGN. We select these objects by identifying galaxies that exhibit a significant excess in their radio luminosities, compared to what is expected from the observed levels of star-formation activity in these systems. This is achieved by comparing the optical (spectroscopic) star formation rate (SFR) to the 1.4~GHz luminosity measured from the FIRST survey. The majority of the AGN identified in this study are fainter than those in previous work, such as in the Best and Heckman (2012) catalogue. We show that these faint AGN make…
The joint catalogue of Active Galactic Nuclei selected from optical identifications of X-ray sources was created as a combination of two samples: Hamburg-ROSAT Catalogue (HRC) and Byurakan-Hamburg-ROSAT Catalogue (BHRC). Both are based on optical identifications of X-ray sources from ROSAT catalogues using low-dispersion spectra of Hamburg Quasar Survey (HQS). However, HRC and BHRC contain a number of misidentifications and using the recent optical and multiwavelength (MW) catalogues we have revised both samples excluding false AGN and adding new genuine ones. Thus a new large homogeneous comp…
A complete catalogue of broad-line AGNs and double-peaked emission lines from MaNGA integral-field spectroscopy of 10K galaxies: stellar population of AGNs, supermassive black holes, and dual AGNs
X-rays offer a reliable method to identify Active Galactic Nuclei (AGN). However, in the high-redshift Universe X-ray AGN are poorly sampled due to their relatively low space density and the small areas covered by X-ray surveys. In addition to wide-area X-ray surveys, it is important to have deep optical data in order to locate the optical counterparts and determine their redshifts. In this work, we build a high-redshift ($z\geqslant3.5$) X-ray selected AGN sample in the XMM-XXL northern field using the most updated [0.5-2 keV] catalogue along with a plethora of new spectroscopic and multi-wav…
(Abridged) Conventional radio surveys of deep fields ordinarily have arc-second scale resolutions often insufficient to reliably separate radio emission in distant galaxies originating from star-formation and AGN-related activity. Very long baseline interferometry (VLBI) can offer a solution by identifying only the most compact radio emitting regions in galaxies at cosmological distances where the high brightness temperatures (in excess of $10^5$ K) can only be reliably attributed to AGN activity. We present the first in a series of papers exploring the faint compact radio population using a n…
This is the second of two papers describing the observations and source catalogues derived from sensitive 3-GHz images of the Lockman Hole North using the Karl G. Jansky Very Large Array. We describe the reduction and cataloguing process, which yielded an image with 8 arcsec resolution and instrumental noise of σ$_{\rm n}$=1.0 μJy beam$^{-1}$ rms (before primary beam corrections) and a catalogue of 558 sources detected above 5σ$_{\rm n}$. We include details of how we estimate source spectral indices across the 2-GHz VLA bandwidth, finding a median index of -0.76$\pm$0.04. Stacking of source sp…
We presented CAIXA, a Catalogue of AGN in the XMM-Newton Archive, in a companion paper. Here, a systematic search for correlations between the X-ray spectral properties and the multiwavelength data was performed for the sources in CAIXA. All the significant (>99.9% confidence level) correlations are discussed along with their physical implications on current models of AGN. Two main correlations are discussed in this paper: a) a very strong anti-correlation between the FWHM of the H$β$ optical line and the ratio between the soft and the hard X-ray luminosity. Although similar anti-correlations …
A catalogue of Type 2 active galactic nuclei in the 6dF Galaxy Survey
University of Melbourne（墨尔本大学）；ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)（三维全天空天体物理学卓越中心）；Research School of Astronomy and Astrophysics (RSAA), Australian National University（澳大利亚国立大学天文与天体物理研究学院）；Centre for Gravitational Astrophysics, Australian National University（澳大利亚国立大学引力天体物理中心）
We present the latest results of a semi-analytic model of galaxy formation, "New Numerical Galaxy Catalogue", which is combined with large cosmological N-body simulations. This model can reproduce statistical properties of galaxies at z < 6.0. We focus on the properties of active galactic nuclei (AGNs) and supermassive black holes, especially on the accretion timescale onto black holes. We find that the number density of AGNs at z < 1.5 and at hard X-ray luminosity 10^{ 44 }< erg/s is underestimated compared with recent observational estimates when we assume the exponentially decreasing accret…
A large fraction of active galactic nuclei (AGN) are "invisible" in extant optical surveys due to either distance or dust-obscuration. The existence of this large population of dust-obscured, infrared-bright AGN is predicted by models of galaxy - supermassive black hole coevolution and is required to explain the observed X-ray and infrared backgrounds. Recently, infrared colour-cuts with WISE have identified a portion of this missing population. However, as the host galaxy brightness relative to that of the AGN increases, it becomes increasingly difficult to differentiate between infrared emis…
We present the results of X-ray spectral analysis of 22 active galactic nuclei (AGNs) with a small scattering fraction selected from the Second XMM-Newton Serendipitous Source Catalogue using hardness ratios. They are candidates of buried AGNs, since a scattering fraction, which is a fraction of scattered emission by the circumnuclear photoionized gas with respect to direct emission, can be used to estimate the size of the opening part of an obscuring torus. Their X-ray spectra are modeled by a combination of a power law with a photon index of 1.5-2 absorbed by a column density of 10^23-24 cm^…
This work presents the catalogue of optical spectral properties for all X-ray selected SPIDERS active galactic nuclei (AGN) up to SDSS DR14. SPIDERS (SPectroscopic IDentification of eROSITA Sources) is an SDSS-IV programme that is currently conducting optical spectroscopy of the counterparts to the X-ray selected sources detected in the ROSAT all-sky survey and the XMM-Newton slew survey in the footprint of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS). The SPIDERS DR14 sample is the largest sample of X-ray selected AGN with optical spectroscopic follow-up to date. The catalogue…
Identification of high-redshift X-ray active galactic nuclei in the 4XMM-DR11 serendipitous catalogue using DES data: Comparative analysis with optically-selected QSOs
We present a catalogue of bulgeless galaxies, which includes 19225 objects selected in four of the deepest, largest multi-wavelength datasets available -- COSMOS, AEGIS, GEMS and GOODS -- at intermediate redshift ($0.4 \leq z \leq 1.0$). The morphological classification was provided by the Advanced Camera for Surveys General Catalogue (ACS-GC), which used publicly available data obtained with the ACS instrument on the Hubble Space Telescope. Rest-frame photometric quantities were derived using kcorrect. We analyse the properties of the sample and the evolution of pure-disc systems with redshif…
Announcing the release v6.4 of the Milliquas (Million Quasars) quasar catalogue which presents all published quasars to 11 December 2019, including SDSS-DR16. Its totals are 757,991 type-I QSOs/AGN and approx 1.1M high-confidence (80%+ likelihood) quasar candidates from SDSS-based & AllWISE photometric quasar catalogs, plus all-sky radio/X-ray associated candidates available only here. Type-II and Bl Lac objects are also included, plus candidates/galaxies with double radio lobes (so calculated), bringing the total count to 1,968,377. Gaia-DR2 astrometry is given for most objects. The catalogue…
We investigated the archival ground-based VLBI images of the extragalactic radio sources included in both the {\it Wilkinson Microwave Anisotropy Probe (WMAP)} and the {\it Planck} catalogues, and selected 49 bright and compact sources as potential targets for space Very Long Baseline Interferometry (VLBI) observations at mm wavelengths. These sources have a flat radio continuum spectrum between 33 and 94~GHz. They are identified as core-dominated active galactic nuclei (AGN), located at declinations above $-40\degr$, and have never been observed with ground-based VLBI at 86~GHz. The radio pro…
Active Galactic Nuclei (AGNs) are characterized by emission of radiation over more than 10 orders of magnitude in frequency. Therefore, the execution of extensive surveys of the sky, with different types of detectors, is providing the attractive possibility to identify and to investigate the properties of AGNs on very large statistical samples. Thanks to the large spectroscopic surveys that allow detailed investigation of many of these sources, we have the opportunity to place new constraints on the nature and evolution of AGNs and to investigate their relations with the host systems. In this …
Mid-IR colour selection techniques have proved to be very efficient in finding AGN. This is because the AGN heats the surrounding dust producing warm mid-IR colours. Using the WISE 3.6, 4.5 and 12 $μm$ colours, the largest sample of IR selected AGN has already been produced containing 1.4 million AGN over the whole sky. Here, we explore the X-ray properties of this AGN sample by cross-correlating it with the subsample of the 3XMM X-ray catalogue that has available X-ray spectra and at the same time optical spectroscopy from SDSS. Our goal is to find rare luminous obscured AGN. Our final sample…
(Abridged) We present simultaneous optical--to--X-ray spectral energy distributions (SEDs) from Swift's X-ray and UV--optical telescopes (XRT and UVOT) for a well-selected sample of 26 low-redshift (z<0.1) AGN from the Swift/BAT 9-month catalogue, the largest well-studied, hard X-ray selected survey of local AGN to date. Our subsample consists of AGN with low intrinsic X-ray absorption (N_H<10^22 cm^-2) and minimal spectral complexity, to more accurately recover the intrinsic accretion luminosity in these sources. We perform a correction for host galaxy contamination in all available UVOT filt…
OzSSy1: The Australian Southern Seyfert-1 Spectroscopic Atlas and Catalogue at z < 0.1
Research School of Astronomy and Astrophysics (RSAA), Australian National University（澳大利亚国立大学天体物理与天文研究学院）；Centre for Gravitational Astrophysics (CGA), Australian National University（澳大利亚国立大学引力天体物理中心）；School of Physics, University of Melbourne（墨尔本大学物理学院）；Commonwealth Scientific and Industrial Research Organisation (CSIRO), Space & Astronomy（联邦科学与工业研究组织空间与天文部）
An understanding of the relationship between radio-loud active galaxies and their large-scale environments is essential for realistic modelling of radio-galaxy evolution and environmental impact, for understanding AGN triggering and life cycles, and for calibrating galaxy feedback in cosmological models. We use the LOFAR Two-Metre Sky Survey (LoTSS) Data Release 1 catalogues to investigate this relationship. We cross-matched 8,745 radio-loud AGN with 0.08<z<0.4, selected from LoTSS, with two Sloan Digital Sky Survey cluster catalogues, and find that only 10 percent of LoTSS AGN in this redshif…
In the context of the upcoming SRG/eROSITA survey, we present an N-body simulation-based mock catalogue for X-ray selected AGN samples. The model reproduces the observed hard X-ray AGN luminosity function (XLF) and the soft X-ray logN-logS from redshift 0 to 6. The XLF is reproduced to within $\pm5\%$ and the logN-logS to within $\pm20\%$. We develop a joint X-ray -- optical extinction and classification model. We adopt a set of empirical spectral energy distributions to predict observed magnitudes in the UV, optical and NIR. With the latest eROSITA all sky survey sensitivity model, we create …
We present the Large Area Radio Galaxy Evolution Spectroscopic Survey (LARGESS), a spectroscopic catalogue of radio sources designed to include the full range of radio AGN populations out to redshift z = 0.8. The catalogue covers roughly 800 square degrees of sky, and provides optical identifications for 19,179 radio sources from the 1.4 GHz Faint Images of the Radio Sky at Twenty-cm (FIRST) survey down to an optical magnitude limit of i_mod < 20.5 in Sloan Digital Sky Survey (SDSS) images. Both galaxies and point-like objects are included, and no colour cuts are applied. In collaboration with…
We investigate the clustering and dark halo properties for the narrow-line active galactic nuclei (AGN) in the SDSS, particularly examining the joint dependence on galaxy mass and color. AGN in galaxies with blue colors or massive red galaxies with M*>~10^{10.5}Msun are found to show almost identical clustering amplitudes at all scales to control galaxies of the same mass, color and structural parameters. This suggests AGN activity in blue galaxies or massive red galaxies is regulated by internal processes, with no correlation with environment. The antibias of AGN at scales between ~100kpc and…
We study the host galaxy properties of active galactic nuclei (AGN) that have been detected in X-rays in the nearby Universe ($\rm z<0.2$). For that purpose, we use the catalogue provided by the ROSAT-2RXS in the 0.1-2.4\,keV energy band, one of the largest X-ray datasets with spectroscopic observations. Our sample consists of $\sim 900$ X-ray AGN. The catalogue provides classification of the sources into type 1 and 2, based on optical spectra. $\sim 25\%$ of the AGN are type 2. We use the available optical, near-IR and mid-IR photometry to construct SEDs. We measure the stellar mass ($M_*$) a…
The variability of the X-ray spectra of active galactic nuclei (AGN) usually includes a change of the spectral slope. This has been investigated for a small sample of local AGNs by Sobolewska and Papadakis, who found that slope variations are well correlated with flux variations, and that spectra are typically steeper in the bright phase (softer when brighter behaviour). Not much information is available for the spectral variability of high-luminosity AGNs and quasars. In order to investigate this phenomenon, we use data from the XMM-Newton Serendipitous Source Catalogue, Data Release 5, which…
Compton-thick AGN Characterisation in a Multi-wavelength Context: Insights from the 70-Month \textit{SWIFT}/BAT Catalogue
Radio Cosmology Research Lab, Centre for Astronomy and Astrophysics Research, Faculty of Science, Universiti Malaya（马来亚大学理学院天体物理学与天文学研究中心射电宇宙学实验室）；Centre of Foundation, Language and Malaysian Studies, Universiti Malaya-Wales（马来亚-威尔士大学基础、语言与马来西亚研究中心）；National Centre for Particle Physics (NCPP), Universiti Malaya（马来亚大学国家粒子物理中心）；National Astronomical Observatory of Japan, National Institutes of Natural Sciences (NINS)（日本国立天文台，国立自然科学研究所）；Department of Astronomical Science, SOKENDAI (The Graduate University of Advanced Studies)（尖端研究大学院大学天体科学系）；Natural Science Laboratory, Toyo University（东洋大学自然科学实验室）；Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia（马来西亚国民科技大学理学院应用物理系）
Since its launch in 1999, the XMM-\textit{Newton} mission has compiled the largest catalogue of serendipitous X-ray sources, with the 3XMM being the third version of this catalogue. This is because of the combination of a large effective area (5000 $\rm cm^2$ at 1 keV) and a wide field of view (30 arcmin). The 3XMM-DR6 catalogue contains about 470,000 unique X-ray sources over an area of 982 $\rm deg^2$. A significant fraction of these (100,178 sources) have reliable optical, near/mid-IR counterparts in the SDSS, PANSTARRS, VIDEO, UKIDSS and WISE surveys. In a previous paper we have presented …
Active galactic nuclei (AGNs) are known to cover an extremely broad range of radio luminosities and the spread of their radio-loudness is very large at any value of the Eddington ratio. This implies very diverse jet production efficiencies which can result from the spread of the black hole spins and magnetic fluxes. Magnetic fluxes can be developed stochastically in the innermost zones of accretion discs, or can be advected to the central regions prior to the AGN phase. In the latter case there could be systematic differences between the properties of galaxies hosting radio-loud (RL) and radio…
Identifying Active Galactic Nuclei (AGNs) through their X-ray emission is efficient, but necessarily biased against X-ray-faint objects. We aim to characterize this bias by comparing X-ray-selected AGNs to the ones identified through optical variability and mid-IR colours. We present a catalogue of AGNs selected through optical variability using all publicly available z-band Hubble Space Telescope images in the GOODS-South field. For all objects in the catalogue, we compute X-ray upper limits or discuss detections in the deepest available 7 Ms Chandra Deep Field South images and present the Sp…
The X-ray spectra of active galactic nuclei (AGN) unveil properties of matter around the super massive black hole (SMBH). We investigate the X-ray spectra of AGN focusing on Compton reflection and fluorescence, important processes of interaction between primary radiation and circum-nuclear material. Unresolved emission lines (most notably the Fe line) in the X-ray spectra of AGN indicate that this material is located far away from the SMBH. Contributions from the inner accretion disk, affected by relativistic effects, have also been detected in several cases. We studied the average X-ray spect…
We discuss whether modern machine learning methods can be used to characterize the physical nature of the large number of objects sampled by the modern multi-band digital surveys. In particular, we applied the MLPQNA (Multi Layer Perceptron with Quasi Newton Algorithm) method to the optical data of the Sloan Digital Sky Survey - Data Release 10, investigating whether photometric data alone suffice to disentangle different classes of objects as they are defined in the SDSS spectroscopic classification. We discuss three groups of classification problems: (i) the simultaneous classification of ga…
Aims.The main purpose of this study is to investigate aspects regarding the validity of the active galactic nucleus (AGN) unification paradigm (UP). In particular, we focus on the AGN host galaxies, which according to the UP should show no systematic differences depending on the AGN classification. Methods.For the purpose of this study, we used (a) the spectroscopic Sloan Digital Sky Survey (SDSS) Data Release (DR) 14 catalogue, in order to select and classify AGNs using emission line diagnostics, up to a redshift of z=0.2, and (b) the Galaxy Zoo Project catalogue, which classifies SDSS galaxi…
We investigate the relationship between the black hole accretion rate (BHAR) and star-formation rate (SFR) for Milky Way (MW) and Andromeda (M31)-mass progenitors from z = 0.2 - 2.5. We source galaxies from the Ks-band selected ZFOURGE survey, which includes multi-wavelenth data spanning 0.3 - 160um. We use decomposition software to split the observed SEDs of our galaxies into their active galactic nuclei (AGN) and star-forming components, which allows us to estimate BHARs and SFRs from the infrared (IR). We perform tests to check the robustness of these estimates, including a comparison to BH…
[abridged] Building upon a previous study, we define a method to blindly identify galaxies that underwent, and may still be undergoing, a fast downfall of their star-formation activity, that is, a more than 80% drop in star-formation rate (SFR) occurring in less than 500 Myr. Modeling galaxies' SED with a delayed-$τ$ star formation history (SFH), with and without allowing an instantaneous SFR drop within the last hundreds Myr, we isolate 102 candidates out of a subsample of 6,680 galaxies classified as star-forming from the UVJ criterion in the ZFOURGE catalogues. These galaxies are mostly loc…
We use AGN with $\rm L_{X} \sim 10^{42.5-44}\,erg\,s^{-1}$, from the COSMOS-Legacy survey that lie within the UltraVISTA region and cross match them with the LEGA-C catalogue. The latter provides measurements of the calcium break, D$_n$4000, and H$_δ$ Balmer line that allow us to study the stellar populations of AGN and compare them with a galaxy reference catalogue. Our samples consist of 69 AGN and 2176 non-AGN systems, within $\rm 0.6<z<1.3$, that satisfy the same photometric selection criteria. We construct the SEDs of both population and use the CIGALE code to investigate the effect of th…
Deep far-UV observations of the ELAIS N1 field using AstroSat: Source catalogue, spectral energy distribution modelling and star formation
Indian Institute of Technology Indore（印度印多尔理工学院）；Max Planck Institute for Solar System Research（马克斯·普朗克太阳系研究所）；Inter-University Centre for Astronomy and Astrophysics（大学间天文学与天体物理学中心）
With the aim of providing the complete demography of galaxies in the local Universe, including their nuclear properties, we present SPRING, a complete census of local galaxies limited to the spring quarter of the Northern sky (10h< RA <16h; 0< Dec <65). The SPRING catalogue is a flux- and volume-limited sample (r < 17.7 mag, cz < 10000 km/s) of 30597 galaxies, including the Virgo, Coma and A1367 clusters. To inspect possible secular and environmental dependencies of the various nuclear excitation properties (SF vs. AGN), we perform a multidimensional analysis by dividing the sample according t…
We look to provide a detailed description of the SPectroscopic IDentification of ERosita Sources (SPIDERS) survey, an SDSS-IV programme aimed at obtaining spectroscopic classification and redshift measurements for complete samples of sufficiently bright X-ray sources. We describe the SPIDERS X-ray Point Source Spectroscopic Catalogue, considering its store of 11,092 observed spectra drawn from a parent sample of 14,759 ROSAT and XMM sources over an area of 5,129 deg$^2$ covered in SDSS-IV by the eBOSS survey. This programme represents the largest systematic spectroscopic observation of an X-ra…
We report the virial measurements of the BH mass of a sample of 17 type 2 AGN, drawn from the Swift/BAT 70-month 14-195 keV hard X-ray catalogue, where a faint BLR component has been measured via deep NIR (0.8-2.5 $μ$m) spectroscopy. We compared the type 2 AGN with a control sample of 33 type 1 AGN. We find that the type 2 AGN BH masses span the 5$<$ log(M$_{BH}$ /M$_{\odot}$) $< $7.5 range, with an average log(M$_{BH}$/M$_{\odot}$) = 6.7, which is $\sim$ 0.8 dex smaller than found for type 1 AGN. If type 1 and type 2 AGN of the same X-ray luminosity log($L_{14-195}$/erg s$^{-1}$) $\sim$ 43.5 …
Virial-based methods for estimating active supermassive black hole masses are now commonly used on extremely large spectroscopic quasar catalogues. Most spectral analyses, though, do not pay enough attention to a detailed continuum decomposition. To understand how this affects virial mass estimate results, we test the influence of host galaxy light on them, along with Balmer continuum component. A detailed fit with the new spectroscopic analysis software QSFit demonstrated that the presence or absence of continuum components do not affect significantly the virial-based results for our sample. …
