We present an analysis of the X-ray point source populations in 182 Chandra images of galaxy clusters at z>0.1 with exposure time >10 ksec, as well as 44 non-cluster fields. Analysis of the number and flux of these sources, using a detailed pipeline to predict the distribution of non-cluster sources in each field, reveals an excess of X-ray point sources associated with the galaxy clusters. A sample of 148 galaxy clusters at 0.1<z<0.9, with no other nearby clusters, show an excess of 230 cluster sources in total, an average of ~1.5 sources per cluster. The lack of optical data for these clusters limits the physical interpretation of this result, as we cannot calculate the fraction of cluster galaxies hosting X-ray sources. However, the fluxes of the excess sources indicate that over half of them are very likely to be AGN, and the radial distribution shows that they are quite evenly distributed over the central 1 Mpc of the cluster, with almost no sources found beyond this radius. We also use this pipeline to successfully reproduce the results of previous studies, particularly the higher density of sources in the central 0.5 Mpc of a few cluster fields, but show that these conclusions are not generally valid for this larger sample of clusters. We conclude that some of these differences may be due to the sample properties, such as the size and redshift of the clusters studied, or a lack of publications for cluster fields with no excess sources. This paper also presents the basic X-ray properties of the galaxy clusters, and in subsequent papers in this series the dependence of the AGN population on these cluster properties will be evaluated.
In addition the properties of over 9500 X-ray point sources in the fields of galaxy clusters are tabulated in a separate catalogue available online.
A Multi-wavelength Survey of AGN in Massive Clusters: AGN Distribution and Host Galaxy Properties
通过在大质量星系团中识别活动星系核所在的星系以及它们周围的场，研究了环境对活动星系核的存在和供给的影响。我们已经通过光变（178）、X射线发射（74）和中红外SEDs（64）在多波长巡天中识别了活动星系核候选者，这些巡天覆盖了以12个星系团为中心的区域，红移为0.5 < z < 0.9。在本文中，我们提出的径向分布的活动星系核在集群研究如何本地环境的影响，活动星系核和它的宿主星系的存在。虽然星系核的径向分布随星系团的不同而不同，但我们发现活动星系核的径向分布一般不同于正常星系。活动星系核的宿主星系也显示出与正常星系不同的颜色分布，许多活动星系核的宿主星系在红色序列和蓝色恒星形成的正常星系之间的“绿色山谷”中显示星系颜色。这一结果与在实地星系研究中发现的结果相似。AGN主机的颜色分布是更明显的干扰集群的小合并，星系骚扰，并与集群子结构的相互作用可能会继续促使恒星形成的主机。然而，我们发现没有主机星系的颜色和星系团半径之间的关系活动星系核主机。这可能表明，与吸积超大质量黑洞相关的过程对宿主星系的恒星形成特性的影响比团内介质和/或局部星系环境更大。
The occurrence of dual active galactic nuclei (AGN) on scales of a few tens of kpc can be used to study merger-induced accretion on massive black holes (MBHs) and to derive clues on MBH mergers, using dual AGN as a parent population of precursors. We investigate the properties of dual AGN in the cosmological simulation Horizon-AGN. We create catalogs of dual AGN selected with distance and luminosity criteria, plus sub-catalogs where further mass cuts are applied. We divide the sample into dual AGN hosted in different galaxies, on the way to a merger, and into those hosted in one galaxy, after …
We perform a comparative study of AGNs in pairs, triplets and groups. To this end we use the Duplancic et al. catalogue of small galaxy systems and consider BPT and WHAN diagnostic diagrams to select optical AGNs. Also we identify mid-IR AGNs by using WISE data. We performed a comparison between the different AGN classification methodologies and study the AGN fraction in pairs, triplets, and groups with four to six members. We also analyse the main properties of Optical and mid-IR AGN hosts and the influence of environment on the active nuclei phenomena in these small galaxy systems. Our resul…
Galaxy mergers are likely to play a role in triggering active galactic nuclei (AGN), but the conditions under which this process occurs are poorly understood. In Paper I, we constructed a sample of spatially offset X-ray AGN that represent galaxy mergers hosting a single AGN. In this paper, we use our offset AGN sample to constrain the parameters that affect AGN observability in galaxy mergers. We also construct dual AGN samples with similar selection properties for comparison. We find that the offset AGN fraction shows no evidence for a dependence on AGN luminosity, while the dual AGN fractio…
It is widely assumed that long-wavelength infrared (IR) emission from cold dust (T~20-40K) is a reliable tracer of star formation even in the presence of a bright active galactic nucleus (AGN). Based on radiative transfer (RT) models of clumpy AGN tori, hot dust emission from the torus contributes negligibly to the galaxy spectral energy distribution (SED) at $λ\ga100$ \micron. However, these models do not include AGN heating of host-galaxy-scale diffuse dust, which may have far-IR (FIR) colors comparable to cold diffuse dust heated by stars. To quantify the contribution of AGN heating to host…
Simulations expect an enhanced star-formation and active galactic nuclei (AGN) activity during galaxy mergers, which can lead to formation of binary/dual AGN. AGN feedback can enhance or suppress star-formation. We have carried out a pilot study of a sample of 10 dual nuclei galaxies with AstroSat's Ultraviolet Imaging Telescope (UVIT). Here, we present the initial results for two sample galaxies (Mrk 739, ESO 509) and deep multi-wavelength data of another galaxy (Mrk 212). UVIT observations have revealed signatures of positive AGN feedback in Mrk 739 and Mrk 212, and negative feedback in ESO …
A systematic study of AGN feedback in a disk galaxy I: global overview
Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；University of Chinese Academy of Sciences（中国科学院大学）；Fudan University（复旦大学）；Peking University（北京大学）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Nanjing University（南京大学）
We have modelled the line ratios and the continuum spectral energy distribution (SED) of the short gamma-ray burst GRB100628A host galaxy complex. The results suggest that an active galactic nucleus (AGN) and a star-burst (SB) coexist in Nicuesa Guelbenzu et al.'s 'galaxy C'. The AGN spectrum is explained by a relatively strong flux. Two of the observed regions (blobs) are located in the ISM, outside the AGN photoionization cones. The strongest Hb line flux calculated by a SB dominated model was found in the tidal tail of galaxy C, while the strongest Hb line flux calculated by an AGN dominate…
Measuring the star-forming properties of AGN hosts is key to our understanding of galaxy formation and evolution. However, this topic remains debated, partly due to the difficulties in separating the infrared (i.e. 1--1000 $μ$m) emission into AGN and star-forming components. Taking advantage of archival far-infrared data from Herschel, we present a new set of AGN and galaxy infrared templates, and introduce the spectral energy distribution fitting code IRAGNSEP. Both can be used to measure infrared host galaxy properties, free of AGN contamination. To build these, we used a sample of 100 local…
A systematic study of AGN feedback in a disk galaxy using MACER. III. High Gas Fractions in AGN Hosts
Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；University of Chinese Academy of Sciences（中国科学院大学）；Fudan University（复旦大学）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学天体物理与天文卡弗里研究所）；Peking University（北京大学）
We present results from the MOSFIRE Deep Evolution Field (MOSDEF) survey on the identification, selection biases, and host galaxy properties of 55 X-ray, IR and optically-selected active galactic nuclei (AGN) at $1.4 < z < 3.8$. We obtain rest-frame optical spectra of galaxies and AGN and use the BPT diagram to identify optical AGN. We examine the uniqueness and overlap of the AGN identified at different wavelengths. There is a strong bias against identifying AGN at any wavelength in low mass galaxies, and an additional bias against identifying IR AGN in the most massive galaxies. AGN hosts sp…
We present a joint analysis of the rest-frame ultraviolet (UV) luminosity functions of continuum-selected star-forming galaxies and galaxies dominated by active galactic nuclei (AGNs) at $z \sim$ 4. These 3,740 $z \sim$ 4 galaxies are selected from broad-band imaging in nine photometric bands over 18 deg$^2$ in the \textit{Spitzer}/HETDEX Exploratory Large Area Survey (SHELA) field. The large area and moderate depth of our survey provide a unique view of the intersection between the bright end of the galaxy UV luminosity function (M$_{AB}<-$22) and the faint end of the AGN UV luminosity functi…
We present spatially resolved kinematic measurements of stellar and ionized gas components of dwarf galaxies in the stellar mass range $10^{8.5} - 10^{10} M_{\odot}$, selected from SDSS DR7 and DR8 and followed-up with Keck/LRIS spectroscopy. We study the potential effects of active galactic nuclei (AGN) on galaxy-wide gas kinematics by comparing rotation curves of 26 galaxies containing AGN, and 19 control galaxies with no optical or infrared signs of AGN. We find a strong association between AGN activity and disturbed gas kinematics in the host galaxies. While star forming galaxies in this s…
We investigate what shapes the infrared luminosity function of local galaxies by comparing it to the local infrared AGN luminosity function. The former corresponds to emission from dust heated by stars and AGN, whereas the latter includes emission from AGN-heated dust only. Our results show that infrared emission from AGN starts mixing into the galaxy luminosity function in the luminous infrared galaxy (LIRG) regime and becomes significant in the ultraluminous infrared galaxy (ULIRG) regime, with the luminosity above which local ULIRGs become AGN-dominated being in the log(LIR/Lsun)~12.2-12.7 …
Double-peaked narrow emission lines in active galactic nucleus (AGN) spectra can be produced by AGN outflows, rotation, or dual AGNs, which are AGN pairs in ongoing galaxy mergers. Consequently, double-peaked narrow AGN emission lines are useful tracers of the coevolution of galaxies and their supermassive black holes, as driven by AGN feedback and AGN fueling. We investigate this concept further with follow-up optical longslit observations of a sample of 95 Sloan Digital Sky Survey (SDSS) galaxies that have double-peaked narrow AGN emission lines. Based on a kinematic analysis of the longslit…
We present an analysis of the radial distribution of Active Galactic Nuclei (AGN) in $2300$ galaxy clusters from the Massive and Distant Clusters of {\it WISE} Survey (MaDCoWS). MaDCoWS provides the largest coverage of the extragalactic sky for a cluster sample at $z\sim1$. We use literature catalogs of AGN selected via optical, mid-infrared (MIR), and radio data, and by optical-to-MIR (OIR) color. Stacking the radial distribution of AGN within the $6\arcmin$ of the centers of MaDCoWS galaxy clusters, we find a distinct overdensity of AGN within $1\arcmin$ of the galaxy cluster center for AGN …
Measurement of black hole mass for low-$z$ ($z\leq 0.8$) Active Galactic Nuclei (AGNs) is difficult due to the strong contribution from host galaxy stellar light necessitating detailed spectral decomposition to estimate the AGN luminosity. Here, we present an empirical relation to estimate host galaxy stellar luminosity from the optical spectra of AGNs at $z\leq 0.8$. The spectral data were selected from the fourteenth data release of the Sloan Digital Sky Survey (SDSS-DR14) quasar catalog having a signal-to-noise ratio at 5100 Å(SNR$_{5100}$) $>$10 containing 11415 quasars. The median total l…
We explore host galaxy properties and environment of a sample of Type 1 and 2 active galactic nuclei (AGN) taken from the COSMOS2015 catalog, within 0.3 $\leq z \leq$ 1.1 selected for their emission in X-rays, optical spectra and SED signatures. We find different properties of host galaxies of distinct AGNs: Type 1 AGNs reside in blue, star-forming and less massive host galaxies compared to Type 2. The majority of the AGNs have intermediate X-ray luminosities, $10^{42}\leq L_X<10^{44}$ \ergs, while only a few have X-ray luminosities ($L_X > 10^{44}$ \ergs) as those observed in QSOs. Non-parame…
Recent deep surveys have unravelled a population of faint active galactic nuclei (AGN) in the high redshift Universe, leading to various discussions on their nature and their role during the Epoch of Reionization. We use cosmological radiation-hydrodynamics simulations of a bright galaxy at z = 6 ($M_\star \gtrsim 10^{10} M_\odot$) hosting an actively growing super-massive black hole to study the properties of these objects. In particular, we study how the black hole and the galaxy co-evolve and what is the relative contribution of the AGN and of the stellar populations to the luminosity budge…
Mapping the average AGN luminosity across galaxy populations and over time encapsulates important clues on the interplay between supermassive black hole (SMBH) and galaxy growth. This paper presents the demography, mean power and cosmic evolution of radio AGN across star-forming galaxies (SFGs) of different stellar masses (${M_{*}}$). We exploit deep VLA-COSMOS 3 GHz data to build the rest-frame 1.4 GHz AGN luminosity functions at 0.1$\leq$$z$$\leq$4.5 hosted in SFGs. Splitting the AGN luminosity function into different ${M_{*}}$ bins reveals that, at all redshifts, radio AGN are both more fre…
Changing-look Active Galactic Nuclei (CL-AGNs) are a subset of AGNs in which the broad Balmer emission lines appear or disappear within a few years. We use the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey to identify five CL-AGNs. The 2-D photometric and kinematic maps reveal common features as well as some unusual properties of CL-AGN hosts as compared to the AGN hosts in general. All MaNGA CL-AGNs reside in the star-forming main sequence, similar to MaNGA non-changing-look AGNs (NCL-AGNs). The $80\% \pm 16\%$ of our CL-AGNs do possess pseudo-bulge features, and follow t…
The co-evolution between central supermassive black holes (BH), their host galaxies, and dark matter halos is still a matter of intense debate. Present theoretical models suffer from large uncertainties and degeneracies, for example, between the fraction of accreting sources and their characteristic accretion rate. In recent work we showed that Active Galactic Nuclei (AGN) clustering represents a powerful tool to break degeneracies when analysed in terms of mean BH mass, and that AGN bias at fixed stellar mass is largely independent of most of the input parameters, such as the AGN duty cycle a…
The interplay between cosmic gas accretion on to galaxies and galaxy mergers drives the observed morphological diversity of galaxies. By comparing the state-of-the-art hydrodynamical cosmological simulations Horizon-AGN and Horizon-noAGN, we unambiguously identify the critical role of active galactic nuclei (AGN) in setting up the correct galaxy morphology for the massive end of the population. With AGN feedback, typical kinematic and morpho-metric properties of galaxy populations as well as the galaxy-halo mass relation are in much better agreement with observations. Only AGN feedback allows …
Post starburst E+A galaxies show indications of a powerful starburst that was quenched abruptly. Their disturbed, bulge-dominated morphologies suggest that they are merger remnants. The more massive E+A galaxies are suggested to be quenched by AGN feedback, yet little is known about AGN-driven winds in this short-lived phase. We present spatially-resolved IFU spectroscopy by the Keck Cosmic Web Imager of SDSS J003443.68+251020.9, at z=0.118. The system consists of two galaxies, the larger of which is a post starburst E+A galaxy hosting an AGN. Our modelling suggests a 400 Myrs starburst, with …
Using a Karl G. Jansky Very Large Array (VLA) L-band (1-2 GHz) survey covering $\sim100$\,deg$^2$ of the Stripe 82 field, we have obtained a catalogue of 2716 radio AGN. For these AGN, we investigate the impact of galaxy density on 1.4 GHz radio luminosity ($L_{1.4}$). We determine their close environment densities using the surface density parameter, $Σ_N,$ for $N=2$ and $N=5,$ which we bin by redshift to obtain a pseudo-3D galaxy density measure. Matching the radio AGN to sources without radio detections in terms of redshift, $K-$band magnitude and ($g-K$)-colour index, we obtain samples of …
The question of whether galaxy mergers are linked to the triggering of active galactic nuclei (AGN) continues to be a topic of considerable debate. The issue can be broken down into two distinct questions: 1) Can galaxy mergers trigger AGN? 2) Are galaxy mergers the dominant AGN triggering mechanism? A complete picture of the AGN-merger connection requires that both of these questions are addressed with the same dataset. In previous work, we have shown that galaxy mergers selected from the Sloan Digital Sky Survey (SDSS) show an excess of both optically-selected, and mid-IR colour-selected AGN…
We present a comparative study of X-ray and IR AGNs at $z\approx2$ to highlight the important AGN selection effects on the distributions of host galaxy properties. Compared with non-AGN star-forming galaxies (SFGs) on the main sequence, X-ray AGNs have similar median star formation (SF) properties, but their incidence (q$_{\rm{AGN}}$) is higher among galaxies with either enhanced or suppressed SF, and among galaxies with larger stellar mass surface density, regardless if it is measured within half-light radius ($Σ_e$) or central 1kpc ($Σ_{\rm{1kpc}}$). Unlike X-ray AGNs, IR AGNs are less massi…
We present a comparative study of active galactic nuclei (AGN) between galaxy pairs and isolated galaxies with the final data release of the MaNGA integral field spectroscopic survey. We build a sample of 391 kinematic galaxy pairs within the footprint of the survey and select AGN using the survey's spectra. We use the comoving volume densities of the AGN samples to quantify the effects that tidal interactions have on the triggering of nuclear accretion. Our hypothesis is that the pair sample contains AGN that are triggered by not only stochastic accretion but also tidally induced accretion an…
In studies of the connection between active galactic nuclei (AGN) and their host galaxies there is widespread disagreement on some key aspects stemming largely from a lack of understanding of the nature of the full underlying AGN population. Recent attempts to probe this connection utilize both observations and simulations to correct for a missed population, but presently are limited by intrinsic biases and complicated models. We take a simple simulation for galaxy evolution and add a new prescription for AGN activity to connect galaxy growth to dark matter halo properties and AGN activity to …
We investigated the properties of AGN environments, particularly environments where the association of luminous galaxies (LGs) is found within 4~Mpc from AGNs with redshifts of 0.8 -- 1.1. For comparison, three additional AGN environments, (namely, AGNs of all types, type~1 AGNs with X-ray and/or radio detection, and type~2 AGNs) and an environment of blue $M_{*}$, characteristic luminosity of the Schechter function, galaxies were investigated. The cross-correlation function with the surrounding galaxies was measured and compared between the AGN and blue galaxy samples. We also compared the di…
Forward modeling of the full galaxy SED is a powerful technique, providing self-consistent constraints on stellar ages, dust properties, and metallicities. However, the accuracy of these results is contingent on the accuracy of the model. One significant source of uncertainty is the contribution of obscured AGN, as they are relatively common and can produce substantial mid-IR (MIR) emission. Here we include emission from dusty AGN torii in the Prospector SED-fitting framework, and fit the UV-IR broadband photometry of 129 nearby galaxies. We find that 10% of the fitted galaxies host an AGN con…
Compared with numerous X-ray dominant active galactic nuclei (AGNs) without emission-line signatures in their optical spectra, the X-ray selected AGNs with optical emission lines are probably still in the high-accretion phase of black hole growth. This paper presents an investigation on the fraction of these X-ray detected AGNs with optical emission-line spectra in 198 galaxy groups at $z<1$ in a rest frame 0.1-2.4 keV luminosity range 41.3 <log(L_X/erg s-1) < 44.1 within the COSMOS field, as well as its variations with redshift and group richness. For various selection criteria of member gala…
Among the many processes involved in galaxy evolution, those of bar formation, quenching, and feedback from an active galactic nucleus (AGN) seem to be connected, however, the nature of these relations remains unclear. In this work, we aim to elucidate them by studying the formation of a barred galaxy in a major merger of two disks in the IllustrisTNG simulations. This merger involves a coalescence of two supermassive black holes and a sudden switch to the kinetic mode of AGN feedback implemented in the simulations, which leads to the removal of the gas from the inner part of the galaxy, follo…
Active galactic nucleus (AGN) feedback provides the link between the central black hole and its host galaxy. We assume AGN feedback driven by radiation pressure on dust, which sweeps up the ambient dusty gas into an outflowing shell, and consider feedback-triggered star formation in the outflow. An upper limit to the characteristic size of galaxies may be defined by the critical radius beyond which radiation pressure on dust is no longer able to drive the shell. The corresponding enclosed mass may be compared with the host galaxy bulge mass. We show that the resulting relation between characte…
Aims. We perform clustering measurements of 800 X-ray selected Chandra COSMOS Legacy (CCL) Type 2 AGN with known spectroscopic redshift to probe the halo mass dependence on AGN host galaxy properties, such as galaxy stellar mass Mstar, star formation rate (SFR) and specific black hole accretion rate (BHAR), in the redshift range z = [0 - 3]. Methods. We split the sample of AGN with known spectroscopic redshits according to Mstar, SFR and specific BHAR, while matching the distributions in terms of the other parameters, including redshift. We measure the projected two-point correlation function …
In a previous work, we have proposed a sub-grid model of active galactic nucleus (AGN) feedback by taking into account the state-of-the-art AGN physics, and used that model to study the effect of AGN feedback on the evolution of an isolated elliptical galaxy by performing two dimensional high-resolution (i.e., the Bondi radius is well resolved) simulations. In that work, typical values of model parameters were adopted. In the present work, we extend that study by exploring the effects of uncertainties of parameter values. Such a study is also useful for us to understand the respective roles of…
We use zoom simulations to show how merger-driven disruption of the gas disc in a galaxy provides its central active galactic nucleus (AGN) with fuel to drive outflows that entrain and expel a significant fraction of the circumgalactic medium (CGM). This in turn suppresses replenishment of the interstellar medium, causing the galaxy to quench up to several Gyr after the merger. We start by performing a zoom simulation of a present-day star-forming disc galaxy with the EAGLE galaxy formation model. Then, we re-simulate the galaxy with controlled changes to its initial conditions, using the gene…
We compare the predictions of Horizon-AGN, a hydro-dynamical cosmological simulation that uses an adaptive mesh refinement code, to observational data in the redshift range 0<z<6. We study the reproduction, by the simulation, of quantities that trace the aggregate stellar-mass growth of galaxies over cosmic time: luminosity and stellar-mass functions, the star formation main sequence, rest-frame UV-optical-near infrared colours and the cosmic star-formation history. We show that Horizon-AGN, which is not tuned to reproduce the local Universe, produces good overall agreement with these quantiti…
Most galaxies in clusters have supermassive black holes at their center, and a fraction of those supermassive black holes show strong activity. These active galactic nuclei(AGNs) are an important probe of environmental dependence of galaxy evolution, intra-cluster medium, and cluster-scale feedback. We investigated AGN fraction in one of the largest samples of X-ray selected clusters from the ROSAT and their immediate surrounding field regions below z < 0.5. We found lower average AGN fraction in clusters, (2.37+-0.39)% than for the fields (5.12+-0.16)%. The lower AGN fractions in clusters wer…
We investigated the variation in the fraction of optical active galactic nuclei (AGN) hosts with stellar mass, as well as their local and global environments. Our sample is composed of cluster members and field galaxies at $z \le 0.1$ and we consider only strong AGN. We find a strong variation in the AGN fraction ($F_{AGN}$) with stellar mass. The field population comprises a higher AGN fraction compared to the global cluster population, especially for objects with log $M_* > 10.6$. Hence, we restricted our analysis to more massive objects. We detected a smooth variation in the $F_{AGN}$ with …
Low mass galaxy cluster systems and groups play an essential role in upcoming cosmological studies such as those to be carried out with eROSITA. Though the effects of active galactic nuclei (AGNs) and merging processes are of special importance to quantify biases like selection effects or deviations from hydrostatic equilibrium, they are poorly understood on the galaxy group scale. We present an analysis of recent deep Chandra and XMM-Newton integrations of NGC741, which provides an excellent example of a group with multiple concurrent phenomena: both an old central radio galaxy and a spectacu…
A key challenge in understanding the feedback mechanism of AGN in Brightest Cluster Galaxies (BCGs) is the inherent rarity of catching an AGN during its strong outburst phase. This is exacerbated by the ambiguity of differentiating between AGN and clusters in X-ray observations. If there is evidence for an AGN then the X-ray emission is commonly assumed to be dominated by the AGN emission, introducing a selection effect against the detection of AGN in BCGs. In order to recover these 'missing' clusters, we systematically investigate the colour-magnitude relation around some ~3500 ROSAT All Sky …
We present a combined morphological and X-ray analysis of Was 49, an isolated, dual AGN system notable for the presence of a dominant AGN Was 49b in the disk of the primary galaxy Was 49a, at a projected radial distance of 8 kpc from the nucleus. Using X-ray data from Chandra, NuSTAR, and Swift, we find that this AGN has a bolometric luminosity of L_bol ~ 2 x 10^45 erg/s, with a black hole mass of M_BH=1.3^{+2.9}_{-0.9} x 10^8 M_Sol. Despite its large mass, our analysis of optical data from the Discovery Channel Telescope shows that the supermassive black hole is hosted by a stellar counterpar…
We present the results of a study of the AGN density in a homogeneous and well-studied sample of 167 bona fide X-ray galaxy clusters ($0.1<z<0.5$) from the XXL Survey. The results can provide evidence of the physical mechanisms that drive AGN and galaxy evolution within clusters. The XXL cluster sample mostly comprises poor and moderately rich structures ($M=10^{13} - 4\times10^{14} M_{\rm o}$). Our aim is to statistically study the demographics of cluster AGNs as a function of cluster mass and host galaxy position. To investigate the effect of the environment on AGN activity, we computed the …
We present an analysis of the X-ray Active Galactic Nucleus (AGN) population in a sample of seven massive galaxy clusters in the redshift range $0.35<z<0.45$. We utilize high-quality Chandra X-ray imaging to robustly identify AGN and precisely determine cluster masses and centroids. Follow-up VIMOS optical spectroscopy allows us to determine which AGN are cluster members. Studying the subset of AGN with 0.5-8 keV luminosities $>6.8\times10^{42}~\mathrm{erg~s^{-1}}$, within $r\leq2r_{500}$ (approximately the virial radius), we find that the cluster AGN space density scales with cluster mass as …
We report evidence for star formation quenching in the central 8.6 kpc region of the jellyfish galaxy JO201 which hosts an active galactic nucleus, while undergoing strong ram pressure stripping. The ultraviolet imaging data of the galaxy disk reveal a region with reduced flux around the center of the galaxy and a horse shoe shaped region with enhanced flux in the outer disk. The characterization of the ionization regions based on emission line diagnostic diagrams shows that the region of reduced flux seen in the ultraviolet is within the AGN-dominated area. The CO J$_{2-1}$ map of the galaxy …
[Abridged] We combine extensive spatially-resolved multi-wavelength observations, taken as part of the Close AGN Reference Survey (CARS), for the edge-on disc galaxy HE1353-1917 to characterize the impact of the AGN on its host galaxy via outflows and radiation. Multi-color broad-band photometry is combined with spatially-resolved optical, NIR and sub-mm and radio observations taken with VLT/MUSE, Gemini-N/NIFS, ALMA and the VLA to map the physical properties and kinematics of the multi-phase inter-stellar medium (ISM). We detect a biconical extended narrow-line region (ENLR) ionized by the lu…
Galaxy mergers are key events in galaxy evolution, often causing massive starbursts and fueling active galactic nuclei (AGN). In these highly dynamic systems, it is not yet precisely known how much starbursts and AGN respectively contribute to the total luminosity, at what interaction stages they occur, and how long they persist. Here we estimate the fraction of the bolometric infrared (IR) luminosity that can be attributed to AGN by measuring and modeling the full ultraviolet to far-infrared spectral energy distributions (SEDs) in up to 33 broad bands for 24 merging galaxies with the Code for…
