Dust and gas content of high-redshift galaxies hosting obscured AGN in the CDF-S
Q. D'Amato, R. Gilli, C. Vignali, M. Massardi, F. Pozzi, G. Zamorani, C. Circosta, F. Vito, J. Fritz, G. Cresci, V. Casasola, F. Calura, A. Feltre, V. Manieri, … 展开作者
Q. D'Amato, R. Gilli, C. Vignali, M. Massardi, F. Pozzi, G. Zamorani, C. Circosta, F. Vito, J. Fritz, G. Cresci, V. Casasola, F. Calura, A. Feltre, V. Manieri, D. Rigopoulou, P. Tozzi, C. Norman
备注：
15 pages, 6 figures, 7 tables. Accepted for publication in A&A
Obscured AGN represent a significant fraction of the entire AGN population, especially at high redshift (~70% at z=3--5). They are often characterized by the presence of large gas and dust reservoirs that are thought to sustain and possibly obscure vigorous star formation processes that make these objects shine at far-IR and sub-mm wavelengths. We exploit ALMA Cycle 4 observations of the continuum (~2.1mm) and high-J CO emission of a sample of six X-ray selected SMGs hosting an obscured AGN at z_spec>2.5 in the 7 Ms CDF-S. We measured the masses and sizes of the dust and molecular gas and we derived the gas density and column density on the basis of a uniform sphere geometry. Finally, we compared the measured column densities with those derived from the Chandra X-ray spectra. We detected both the continuum and line emission for three sources for which we measured both the flux density and size. For the undetected sources, we derived an upper limit on the flux density. We found that the detected galaxies are rich in gas and dust (molecular gas mass in the range <0.5 - 2.7 x 10^10 M_sun for α_CO=0.8 and up to ~2 x 10^11~M_sun for α_CO=6.5, and dust mass <0.9 - 4.9 x 10^8 M_sun) and compact (gas major axis 2.1-3.0 kpc, dust major axis 1.4-2.7 kpc). The column densities associated with the ISM are on the order of 10^(23-24) cm-2, which is comparable with those derived from the X-ray spectra. For the detected sources we also derived dynamical masses in the range 0.8 - 3.7 x 10^10 M_sun. We conclude that the ISM of high redshift galaxies can substantially contribute to nuclear obscuration up to the Compton-thick (>10^24 cm-2) regime. In addition, we found that all the detected sources show a velocity gradient reminding one rotating system, even though two of them show peculiar features in their morphology that can be associated with a chaotic, possibly merging, structure.
We present the properties of X-ray detected dust obscured galaxies (DOGs) in the Chandra Deep Field South. In recent years, it has been proposed that a significant percentage of the elusive Compton-thick (CT) active galactic nuclei (AGN) could be hidden among DOGs. In a previous work, we presented the properties of X-ray detected DOGs by making use of the deepest X-ray observations available at that time, the 2Ms observations of the Chandra deep fields. In that work, we only found a moderate percentage ($<$ 50%) of CT AGN among the DOGs sample, but we were limited by poor photon statistics. In…
In active galactic nuclei (AGN)-galaxy co-evolution models, AGN winds and outflows are often invoked to explain why super-massive black holes and galaxies stop growing efficiently at a certain phase of their lives. They are commonly referred to as the leading actors of feedback processes. Evidence of ultra-fast (v>0.05c) outflows in the innermost regions of AGN has been collected in the past decade by sensitive X-ray observations for sizable samples of AGN, mostly at low redshift. Here we present ultra-deep XMM-Newton and Chandra spectral data of an obscured (Nh~2x10^{23} cm^-2), intrinsically…
We present X-ray spectral analysis of the brightest sources (f_{2-10 keV}>10^{-15}$ cgs) in the Chandra Deep Field North. Our sample consists of 222 sources; for the vast majority (171) either a spectroscopic or a photometric redshift is available. Our goal is to discover the Compton-thick AGN in a direct way i.e. through their X-ray spectra. Compton-thick AGN give away their presence in X-rays either directly through the absorption turnover redshifted in the Chandra passband, or through a flat, reflection-dominated, spectrum. The above selection criteria yield 10 Compton-thick AGN candidates …
We use the Wide-field Infrared Survey Explorer (WISE) and the Sloan Digital Sky Survey (SDSS) to confirm a connection between dust-obscured active galactic nuclei (AGNs) and galaxy merging. Using a new, volume-limited (z <= 0.08) catalog of visually-selected major mergers and galaxy-galaxy interactions from the SDSS, with stellar masses above 2x10^10 Msun, we find that major mergers (interactions) are 5-17 (3-5) times more likely to have red [3.4]-[4.6] colors associated with dust-obscured or `dusty' AGNs, compared to non-merging galaxies with similar masses. Using published fiber spectral dia…
AIMS. This work addresses the AGN IR-selection dependency on intrinsic source luminosity and obscuration, in order to identify and charaterise biases which could affect conclusions in studies. METHODS. We study IR-selected AGN in the Chandra Deep Field South (CDFS) survey and in the Cosmological Survey (COSMOS). The AGN sample is divided into low and high X-ray luminosity classes, and into unobscured (type-1) and obscured (type-2) classes by means of X-ray and optical spectroscopy data. Specifically in the X-rays regime, we adopt the intrinsic luminosity taking into account the estimated colum…
The standard AGN-galaxy co-evolutionary scenario predicts a phase of deeply buried supermassive black hole growth coexisting with a starburst (SB) before feedback phenomena deplete the cold molecular gas reservoir of the galaxy and an optically luminous QSO is revealed ('SB-QSO evolutionary sequence'). The aim of this work is to measure the cold gas reservoir of three highly obscured QSOs to test if their gas fraction is similar to that of sub-millimeter galaxies (SMGs), as expected by some models, and place these measurements in the context of the SB-QSO framework. We target CO(1-0) transitio…
Combined observations from UV to IR wavelengths are necessary to fully account for the star-formation in galaxy clusters. Low mass (log M/Msun<10) galaxies are typically not individualy detected, particularly at higher redshifts (z~1-2) where galaxy clusters are undergoing rapid transitions from hosting mostly active, dust-obscured star-forming galaxies to quiescent, passive galaxies. To account for these undetected galaxies, we measure the total light emerging from GALEX/NUV stacks of galaxy clusters between z=0.5-1.6. Combined with existing measurements from Spitzer, WISE, and Herschel, we s…
We present new data for four candidate obscured Compton-Thick (CT) quasars at z $\sim$1-2.5 observed with SINFONI VLT spectrograph in AO mode. These sources were selected from a 24$μ$m Spitzer MIPS survey of the COSMOS field, on the basis of red mid-infrared-to-optical and optical-to-near-infrared colours, with the intention of identifying active galactic nuclei (AGNs) in dust enshrouded environments, where most of the black hole mass is assembled in dust enshrouded environments. Near infrared spectra were analyzed in order to check for emission line features and to search for broad components…
Local Heavily Obscured Active Galaxies Observed With Chandra (I): Spectral Properties of the Nuclear and Extended X-ray Emission
INAF Osservatorio Astronomico di Roma（罗马天文台）；Center for Astrophysics | Harvard & Smithsonian（哈佛-史密森天体物理中心）；NASA Goddard Space Flight Center（戈达德太空飞行中心）；Astronomical Observatory of the Jagiellonian University（亚盖隆大学天文台）；NASA Marshall Space Flight Center（马歇尔太空飞行中心）
The physical parameters of galaxies and/or AGNs can be derived by fitting their multi-band spectral energy distributions (SEDs). By using CIGALE code, we perform multi-band SED fitting (from ultraviolet to infrared) for 791 X-ray sources (518 AGNs and 273 normal galaxies) in the 7 Ms Chandra Deep Field-south survey (CDFS). We consider the contributions from AGNs and adopt more accurate redshifts than published before. Therefore, more accurate star formation rates (SFRs) and stellar masses (M$_*$) are derived. We classify the 518 AGNs into type-I and type-II based on their optical spectra and t…
Probing Heavily Obscured AGN in Major Galaxy Mergers Using the mm-X-ray Correlation
Pontificia Universidad Católica de Chile（智利天主教 Pontificia 大学）；Universidad de Tarapacá（塔拉帕卡大学）；National Radio Astronomy Observatory（美国国家射电天文台）；University of Virginia（弗吉尼亚大学）；Osaka University（大阪大学）；RIKEN Cluster for Pioneering Research（理化学研究所先锋研究集群）；Clemson University（克莱姆森大学）
We present improved point-source catalogs for the 2 Ms Chandra Deep Field-North (CDF-N) and the 250 ks Extended Chandra Deep Field-South (E-CDF-S), implementing a number of recent improvements in Chandra source-cataloging methodology. For the CDF-N/E-CDF-S, we provide a main catalog that contains 683/1003 X-ray sources detected with wavdetect at a false-positive probability threshold of $10^{-5}$ that also satisfy a binomial-probability source-selection criterion of $P<0.004$/$P<0.002$. Such an approach maximizes the number of reliable sources detected: a total of 196/275 main-catalog sources …
We present the multiwavelength properties of 266 cataloged radio sources identified with 20 and 6 cm VLA deep observations of the CDFS at a flux density limit of 42 μJy at the field centre at 1.4 GHz. These new observations probe the faint end of both the star formation and radio galaxy/AGN population. X-ray data, including upper limits, turn out to be a key factor in establishing the nature of faint radio sources. We find that, while the well-known flattening of the radio number counts below 1 mJy is mostly due to star forming galaxies, these sources and AGN make up an approximately equal fra…
We explore the gas ionization and kinematics, as well as the optical--IR spectral energy distributions for UGC 11185, a nearby pair of merging galaxies hosting obscured active galactic nuclei (AGNs), also known as SDSS J181611.72+423941.6 and J181609.37+423923.0 (J1816NE and J1816SW, $z \approx 0.04$). Due to the wide separation between these interacting galaxies ($\sim 23$ kpc), observations of these objects provide a rare glimpse of the concurrent growth of supermassive black holes at an early merger stage. We use BPT line diagnostics to show that the full extent of the narrow line emission …
We present a detailed X-ray spectral analysis of 1152 AGNs selected in the Chandra Deep Fields (CDFs), in order to identify highly obscured AGNs ($N_{\rm H} > 10^{23}\ \rm cm^{-2}$). By fitting spectra with physical models, 436 (38%) sources with $L_{\rm X} > 10^{42}\ \rm erg\ s^{-1}$ are confirmed to be highly obscured, including 102 Compton-thick (CT) candidates. We propose a new hardness-ratio measure of the obscuration level which can be used to select highly obscured AGN candidates. The completeness and accuracy of applying this method to our AGNs are 88% and 80%, respectively. The observ…
AGN Feedback: The impact of galactic-scale radio jets on the interstellar medium in starbursting obscured AGN
INAF – Istituto di Astrofisica Spaziale e Fisica Cosmica Milano（意大利国家天体物理研究所空间天体物理学与宇宙学米兰分院）；Associated Universities, Inc.（联合大学公司）；William H. Miller III Department of Physics and Astronomy, Johns Hopkins University（约翰斯·霍普金斯大学威廉·H·米勒三世物理与天文系）；MIT Haystack Observatory（麻省理工学院海斯塔克天文台）
We present a detailed spectral analysis of the brightest Active Galactic Nuclei (AGN) identified in the 7Ms Chandra Deep Field South (CDF-S) survey over a time span of 16 years. Using a model of an intrinsically absorbed power-law plus reflection, with possible soft excess and narrow Fe K$α$ line, we perform a systematic X-ray spectral analysis, both on the total 7Ms exposure and in four different periods with lengths of 2-21 months. With this approach, we not only present the power-law slopes, column densities $N_H$, observed fluxes, and absorption-corrected 2-10~keV luminosities $L_X$ for ou…
Back to basics: Little Red Dots as galaxies and dust-obscured AGNs in a synthetic NIRCam sky simulated with L-GalaxiesBH
Donostia International Physics Centre (DIPC)（多诺斯蒂亚国际物理中心）；University of the Basque Country UPV/EHU（巴斯克国立大学）；Como Lake Center for AstroPhysics, University of Insubria（因斯布鲁克大学科莫湖天体物理中心）；Dipartimento di Fisica “G. Occhialini”, Università degli Studi di Milano-Bicocca（米兰比可卡大学 G. Occhialini 物理系）；INFN, Sezione di Milano-Bicocca（意大利国家核物理研究所米兰比可卡分部）；Key Laboratory for Computational Astrophysics, National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台计算天体物理学重点实验室）；School of Astronomy and Space Sciences, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天文与天体物理研究所）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（加泰罗尼亚高等研究学院，西班牙国家科研委员会））
Capitalizing on the all-sky coverage of {\it WISE}, and the 35\% and 50\% sky coverage from SDSS and Pan-STARRS, respectively, we explore the efficacy of $m_{R}$ (optical) - $m_{3.4 μm}$ (mid-infrared), hereafter $R-W1$, as a color diagnostic to identify obscured supermassive black hole accretion in wide-area X-ray surveys. We use the $\sim$16.5 deg$^2$ Stripe 82 X-ray survey data as a test-bed to compare $R-W1$ with $R-K$, an oft-used obscured AGN selection criterion, and examine where different classes of objects lie in this parameter space. Most stars follow a well-defined path in $R-K$ vs.…
In contrast to massive, bulge hosting galaxies, very few supermassive black holes (SMBHs) are known in either low mass, or bulgeless galaxies. Such a population could provide clues to the origins of SMBHs and to secular pathways for their growth. Using the all-sky Wide-Field Infrared Survey Explorer (WISE) survey, and bulge-to-disk decompositions from the Sloan Digital Sky Survey (SDSS) Data Release 7, we report the discovery of a population of local (z<0.3) bulgeless disk galaxies with extremely red mid-infrared colors highly suggestive of a dominant active galactic nucleus (AGN), despite hav…
We present X-ray spectra of 185 bright sources detected in the XMM-Newton deep survey of the Chandra Deep Field South, combining the three EPIC cameras. The 2-10 keV flux limit of the sample is 2e-15 erg/s/cm2. The sources are distributed over a redshift range of z=0.1-3.8. Eleven new X-ray redshift measurements are included. A spectral analysis was performed using a simple model to obtain absorbing column densities, rest-frame 2-10 keV luminosities and Fe K line properties of 180 sources at z>0.4. Obscured AGN are found to be more abundant toward higher redshifts. Using the XMM-Newton data al…
In deep X-ray surveys, active galactic nuclei (AGNs) with a broad range of luminosities have been identified. However, cosmologically distant low-luminosity AGN (LLAGN, $L_{\mathrm{X}} \lesssim 10^{42}$ erg s$^{-1}$) identification still poses a challenge due to significant contamination from host galaxies. Based on the 7 Ms Chandra Deep Field-South (CDF-S) survey, the longest timescale ($\sim 17$ years) deep X-ray survey to date, we utilize an X-ray variability selection technique to search for LLAGNs that remain unidentified among the CDF-S X-ray sources. We find 13 variable sources from 110…
The most accepted scenario for the evolution of massive galaxies across cosmic time predicts a regulation based on the interplay between AGN feedback, which injects large amounts of energy in the host environment, and galaxy mergers, being able to trigger massive star formation events and accretion onto the supermassive black holes. Interacting systems hosting AGN are useful laboratories to get key insights into both phenomena. In this context, we present the analysis of the optical spectral properties of IRAS 20210+1121 (I20210), a merging system at $z = 0.056$. According to X-ray data, this …
We have carried out an extensive X-ray spectral analysis of a sample of galaxies exhibiting molecular outflows (MOX sample), to characterize the X-ray properties and investigate the effect of AGN on the dynamical properties of the molecular outflows. We find that the X-ray bolometric correction $(L_{2-10\rm keV}/L_{\rm AGN})$ of these sources ranges from $\sim10^{-4.5}$ to $10^{-0.5}$, with $\sim 70\%$ of the sources below $10^{-2}$, implying a weak X-ray emission relative to the AGN bolometric luminosity ($L_{\rm AGN}$). However, the upper limit on the $2-10\rm keV$ luminosity ($L_{\rm 2-10 k…
We aim to constrain the evolution of AGN as a function of obscuration using an X-ray selected sample of $\sim2000$ AGN from a multi-tiered survey including the CDFS, AEGIS-XD, COSMOS and XMM-XXL fields. The spectra of individual X-ray sources are analysed using a Bayesian methodology with a physically realistic model to infer the posterior distribution of the hydrogen column density and intrinsic X-ray luminosity. We develop a novel non-parametric method which allows us to robustly infer the distribution of the AGN population in X-ray luminosity, redshift and obscuring column density, relying …
In the hierarchical model of structure formation, giant elliptical galaxies form through merging processes within the highest density peaks known as protoclusters. While high-redshift radio galaxies usually pinpoint the location of these environments, we have recently discovered at z~2-3 three Enormous (>200 kpc) Lyman-Alpha Nebulae (ELANe) that host multiple AGN and that are surrounded by overdensities of Lyman-alpha Emitters (LAE). These regions are prime candidates of massive protoclusters in the early stages of assembly. To characterize the star-forming activity within these rare structure…
We present a linear clustering model of cosmic infrared background (CIB) anisotropies at large scales that is used to measure the cosmic star formation rate density up to redshift 6, the effective bias of the CIB and the mass of dark-matter halos hosting dusty star-forming galaxies. This is achieved using the Planck CIB auto- and cross-power spectra (between different frequencies) and CIBxCMB lensing cross-spectra measurements, as well as external constraints (e.g. on the CIB mean brightness). We recovered an obscured star formation history which agrees well with the values derived from infrar…
We present a study of the redshift evolution of the projected correlation function of 593 X-ray selected AGN with I_AB<23 and spectroscopic redshifts z<4, extracted from the 0.5-2 keV X-ray mosaic of the 2.13 deg^2 XMM-COSMOS survey. We introduce a method to estimate the average bias of the AGN sample and the mass of AGN hosting halos, solving the sample variance using the halo model and taking into account the growth of the structure over time. We find evidence of a redshift evolution of the bias factor for the total population of XMM-COSMOS AGN from b(z=0.92)=2.30 +/- 0.11 to b(z=1.94)=4.37 …
We report ALMA Cycle 0 observations at 1.3mm of LESS J033229.4-275619 (XID403), an Ultraluminous Infrared Galaxy at $z=4.75$ in the Chandra Deep Field South hosting a Compton-thick QSO. The source is not resolved in our data at a resolution of $\sim$0.75 arcsec, placing an upper-limit of 2.5 kpc to the half-light radius of the continuum emission from heated-dust. After deconvolving for the beam size, however, we found a $\sim3σ$ indication of an intrinsic source size of $0.27\pm0.08$ arcsec (Gaussian FWHM), which would correspond to $r_{half}\sim0.9\pm0.3$ kpc. We build the far-IR SED of XID40…
We exploit EAGLE, a cosmological hydrodynamical simulation, to reproduce the selection of the observed sub-millimeter (submm) galaxy population by selecting the model galaxies at $z \geq 1$ with mock submm fluxes $S_{850} \geq 1$ mJy. There is a reasonable agreement between the galaxies within this sample and the properties of the observed submm population, such as their star formation rates (SFRs) at $z<3$, redshift distribution and many integrated galaxy properties. We find that the bulk of the $S_{850} \geq 1$ mJy model population is at $z = 2.5$, and that they are massive galaxies ($M_* \s…
We carry out a blind search of 3mm continuum sources using the ALMA Science Archive to derive the first galaxy number counts at this wavelength. The analyzed data are drawn from observations towards three extragalactic legacy fields: COSMOS, CDF-S, and the UDS comprising more than 130 individual ALMA Band 3 pointings and an effective survey area of ~200 sq. arcmin with a continuum sensitivity that allows for the direct detection of unlensed Dusty Star-Forming Galaxies (DSFGs) dust emission beyond the epoch of reionization. We present a catalog of 16 sources detected at >5sigma with flux densit…
We present ALMA observations at 107.291 GHz (band 3) and 214.532 GHz (band 6) of GMASS 0953, a star-forming galaxy at z=2.226 hosting an obscured AGN that has been proposed as a progenitor of compact quiescent galaxies (QG). We measure for the first time the size of the dust and molecular gas emission of GMASS 0953 that we find to be extremely compact ($\sim$1 kpc). This result, coupled with a very high ISM density (n$\sim$10$^{5.5}$ cm$^{-3}$), a low gas mass fraction ($\sim$0.2) and a short gas depletion timescale ($\sim$150 Myr) imply that GMASS 0953 is experiencing an episode of intense st…
NGC 1266 is a lenticular galaxy (S0) hosting an active galactic nucleus (AGN), and known to contain a large amount of shocked gas. We compare the luminosity ratio of mid-\emph{J} CO lines to IR continuum with star-forming galaxies (SFGs), and then model the CO spectral line energy distribution (SLED). We confirm that in the mid- and high-\emph{J} regions ($J_{\rm up}$ = 4--13), the C-type shock ($v_{\rm s}$ = 25 km s$^{-1}$, $n_{\rm H}$ = $5\times10^{4}$ cm$^{-3}$) can reproduce the CO observations well. The galaxy spectral energy distribution (SED) is constructed and modeled by the code {\tt …
The 4 Ms Chandra Deep Field-South (CDF-S) and other deep X-ray surveys have been highly effective at selecting active galactic nuclei (AGN). However, cosmologically distant low-luminosity AGN (LLAGN) have remained a challenge to identify due to significant contribution from the host galaxy. We identify long-term X-ray variability (~month-years, observed frame) in 20 of 92 CDF-S galaxies spanning redshifts z~0.08-1.02 that do not meet other AGN selection criteria. We show that the observed variability cannot be explained by X-ray binary populations or ultraluminous X-ray sources, so the variabi…
The discovery over the last several decades of moderate luminosity AGNs in disk-dominated galaxies - which show no "classical" bulges - suggests that secular mechanisms represent an important growth pathway for supermassive black holes in these systems. We present new follow-up NuSTAR observations of the optically-elusive AGNs in two bulgeless galaxies, NGC 4178 and J0851+3926. NGC 4178 was originally reported as hosting an AGN based on the detection of [Ne V] mid-infrared emission detected by Spitzer, and based on Chandra X-ray imaging it has since been argued to host either a heavily obscure…
Sparks: The Magellan/FIRE survey from starburst to post-starburst
Kavli Institute for Particle Astrophysics & Cosmology, Stanford University（斯坦福大学卡弗里粒子天体物理与宇宙学研究所）；Center for Decoding the Universe, Stanford University（斯坦福大学解码宇宙中心）；Department of Astrophysical Sciences, Princeton University（普林斯顿大学天体物理科学系）；Department of Astronomy and Astrophysics, University of California Santa Cruz（加州大学圣克鲁兹分校天文与天体物理系）；Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU)（宇宙物理与数学卡弗里研究所）；Division of Science, National Astronomical Observatory of Japan（日本国立天文台科学部）；Department of Physics and Astronomy, University of California, Riverside（加州大学河滨分校物理与天文系）；Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理研究所）
We have performed a search over 3440 deg$^2$ of Epoch 1 (2017-2019) of the Very Large Array Sky Survey to identify unobscured quasars in the optical ($0.2 < z < 3.2$) and obscured active galactic nuclei (AGN) in the infrared that have brightened dramatically in the radio over the past one to two decades. These sources would have been previously classified as "radio-quiet" quasars based on upper limits from the Faint Images of the Radio Sky at Twenty Centimeters survey (1993-2011), but they are now consistent with "radio-loud" quasars ($L_{\rm 3\,GHz} = 10^{40 - 42} \,\, {\rm erg} \,{\rm s}^{-1…
Contrary to expectations from scenarios of black hole growth driven by galaxy interactions and mergers, dual active galactic nuclei (AGN) with kiloparsec separations are rarely observed and are very difficult to identify, in particular at high redshifts (i.e. z>2). Focussing on the recently discovered dual AGN system LBQS 0302-0019 at z=3.29, we seek to identify further group members in its environment and to understand their formation history through deep high-angular-resolution imaging. We present deep Hubble Space Telescope (HST) Wide-field Camera 3 near-infrared imaging of LBQS 0302-0019. …
We present narrow- and medium-band HST imaging, with additional supporting ground-based data, for 8 galaxies identified as hosting fading AGN. These have AGN-ionized gas projected >10 kpc from the nucleus, and significant shortfall of ionizing radiation between the distant gas and the AGN, indicating fading AGN on ~50,000-year timescales. Every system shows evidence of ongoing or past interactions; a similar sample of obscured AGN with extended ionized clouds shares this incidence of disturbances. Several systems show multiple dust lanes in different orientations, broadly fit by differentially…
We present six galaxies at z~2 that show evidence of Lyman continuum (LyC) emission based on the newly acquired UV imaging of the Hubble Deep UV legacy survey (HDUV) conducted with the WFC3/UVIS camera on the Hubble Space Telescope (HST). At the redshift of these sources, the HDUV F275W images partially probe the ionizing continuum. By exploiting the HST multi-wavelength data available in the HDUV/GOODS fields, models of the UV spectral energy distributions, and detailed Monte Carlo simulations of the intergalactic medium absorption, we estimate the absolute ionizing photon escape fractions of…
The analysis of the cluster environment is a valuable instrument to investigate the origin of AGN and star-forming galaxies gas fuelling and trigger mechanisms. To this purpose, we present a detailed analysis of the point-like X-ray sources in the Bullet cluster field. Thanks to $\sim600$ ks Chandra observations, we produced a catalogue of 381 X-ray point sources up to a distance of $\sim$1.5 virial radius and with flux limits $\sim1\times10^{-16}$ and $\sim8\times10^{-16}$ erg cm$^{-2}$ s$^{-1}$ in the 0.5-2 keV and 2-10 keV bands, respectively. We found a strong (up to a factor 1.5-2) and si…
We present a catalog of physical properties for galaxies hosting active galactic nuclei (AGN) detected by the Wide-field Infrared Survey Explorer (WISE). By fitting broadband spectral energy distributions of sources in the WISE AGN Catalog (Assef et al. 2018) with empirical galaxy and AGN templates, we derive photometric redshifts, AGN bolometric luminosities, measures of AGN obscuration, host galaxy stellar masses, and host galaxy star formation rates (SFRs) for 695,273 WISE AGN. The wide-area nature of this catalog significantly augments the known number of obscured AGN out to redshifts of z…
XDCP0044.0-2033 is the most massive galaxy cluster known at z>1.5 and its core shows a high density of galaxies which are experiencing mergers and hosting nuclear activity. We present a multi-wavelength study of a region located 157 kpc from the center of this galaxy cluster, for which we have photometric and spectroscopic multi-wavelength observations (high resolution HST images in F105W, F140W and F160W bands, NIR KMOS data in H and YJ bands and Chandra ACIS-S X-ray data). Our main goal is to investigate the environmental effects acting on the galaxies inhabiting this high density region. We…
The nature of galaxies selected at submillimeter wavelengths (SMGs, S_850 > 3 mJy), some of the bolometrically most luminous objects at high redshifts, is still elusive. In particular their star formation histories and source of emission are not accurately constrained. In this paper we introduce a new approach to analyse the SMG data. Namely, we present the first self-consistent UV-to-radio spectral energy distribution fits of 76 SMGs with spectroscopic redshifts using all photometric datapoints from ultraviolet to radio simultaneously. We find that they are highly star-forming (median star fo…
