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42 42

Lower Mass Black Holes in the GOODS? Off-nuclear X-ray Sources

Sep 22, 2013 09/13

by A. E. Hornschemeier; D. M. Alexander; F. E. Bauer; W. N. Brandt; R. Chary; C. Conselice; N. A. Grogin; A. M. Koekemoer; B. Mobasher; M. Paolillo; S. Ravindranath; E. J. Schreier

eye 42

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We have identified a sample of 10 highly reliable off-nuclear (> 2 kpc) X-ray sources at z=0.03-0.25 in late-type host galaxies within the two GOODS fields (i.e., the two Chandra Deep Fields). The combination of the superb spatial resolution and great depth of the HST ACS and Chandra ACIS coverage in the GOODS fields is critical to the identification of these sources. We extend the study of this enigmatic population up to higher redshifts and larger look-back times than has been possible...
Source: http://arxiv.org/abs/astro-ph/0308408v1

Arxiv.org

79 79

A Possible New Population of Sources with Extreme X-Ray / Optical Ratios

Sep 18, 2013 09/13

by Anton M. Koekemoer; D. M. Alexander; F. E. Bauer; J. Bergeron; W. N. Brandt; E. Chatzichristou; S. Cristiani; S. M. Fall; N. A. Grogin; M. Livio; V. Mainieri; L. Moustakas; P. Padovani; P. Rosati; E. J. Schreier; C. M. Urry

eye 79

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We describe a possible new class of X-ray sources that have robust detections in ultra-deep Chandra data, yet have no detections at all in our deep multi-band GOODS Hubble Space Telescope (HST) ACS images, which represent the highest quality optical imaging obtained to date on these fields. These extreme X-ray / Optical ratio sources ("EXO"s) have values of Fx/Fopt at least an order of magnitude above those generally found for other AGN, even those that are harbored by reddened hosts....
Source: http://arxiv.org/abs/astro-ph/0306407v1

Arxiv.org

62 62

X-ray Properties of Lyman Break Galaxies in the Great Observatories Origins Deep Survey

Sep 22, 2013 09/13

by B. D. Lehmer; W. N. Brandt; D. M. Alexander; F. E. Bauer; C. J. Conselice; M. E. Dickinson; M. Giavalisco; N. A. Grogin; A. M. Koekemoer; K. S. Lee; L. A. Moustakas; D. P. Schneider

eye 62

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We constrain the X-ray emission properties of Lyman break galaxies (LBGs) at z ~ 3-6 using the 2 Ms Chandra Deep Field-North and 1 Ms Chandra Deep Field-South. Large samples of LBGs were discovered using HST as part of the Great Observatories Origins Deep Survey (GOODS). Deep optical and X-ray imaging over the GOODS fields have allowed us to place the most significant constraints on the X-ray properties of LBGs to date. Mean X-ray properties of 449, 1734, 629, and 247 LBGs with z ~ 3, 4, 5, and...
Source: http://arxiv.org/abs/astro-ph/0409600v1

Arxiv.org

58 58

Energetic galaxy-wide outflows in high-redshift ultra-luminous infrared galaxies hosting AGN activity

Sep 20, 2013 09/13

by C. M. Harrison; D. M. Alexander; A. M. Swinbank; Ian Smail; S. Alaghband-Zadeh; F. E. Bauer; S. C. Chapman; A. Del Moro; R. C. Hickox; R. J. Ivison; Karin Menendez-Delmestre; J. R. Mullaney; N. P. H. Nesvadba

eye 58

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We present integral field spectroscopy observations, covering the [O III]4959,5007 emission-line doublet of eight high-redshift (z=1.4-3.4) ultra-luminous infrared galaxies (ULIRGs) that host Active Galactic Nuclei (AGN) activity, including known sub-millimetre luminous galaxies (SMGs). The targets have moderate radio luminosities that are typical of high-redshift ULIRGs (L(1.4GHz)=10^(24)-10^(25)W/Hz) and therefore are not radio-loud AGN. We de-couple kinematic components due to the galaxy...
Source: http://arxiv.org/abs/1205.1801v3

Arxiv.org

8 8.0

The host galaxies of X-ray selected Active Galactic Nuclei to z=2.5: Structure, star-formation and their relationships from CANDELS and Herschel/PACS

Jun 30, 2018 06/18

by D. J. Rosario; D. H. McIntosh; A. van der Wel; J. Kartaltepe; P. Lang; P. Santini; S. Wuyts; D. Lutz; M. Rafelski; C. Villforth; D. M. Alexander; F. E. Bauer; E. F. Bell; S. Berta; W. N. Brandt; C. J. Conselice; A. Dekel; S. M. Faber; H. C. Ferguson; R. Genzel; N. A. Grogin; D. D. Kocevski; A. M. Koekemoer; D. C. Koo; J. M. Lotz; B. Magnelli; R. Maiolino; M. Mozena; J. R. Mullaney; C. J. Papovich; P. Popesso; L. J. Tacconi; J. R. Trump; S. Avadhuta; R. Bassett; A. Bell; M. Bernyk; F. Bournaud;...

eye 8

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We study the relationship between the structure and star-formation rate (SFR) of X-ray selected low and moderate luminosity active galactic nuclei (AGNs) in the two Chandra Deep Fields, using Hubble Space Telescope imaging from the Cosmic Assembly Near Infrared Extragalactic Legacy Survey (CANDELS) and deep far-infrared maps from the PEP+GOODS-Herschel survey. We derive detailed distributions of structural parameters and FIR luminosities from carefully constructed control samples of galaxies,...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1409.5122

Arxiv.org

112 112

The Mean Star Formation Rate of X-ray selected Active Galaxies and its Evolution from z=2.5: Results from PEP-Herschel

Jul 20, 2013 07/13

by D. J. Rosario; P. Santini; D. Lutz; L. Shao; R. Maiolino; D. M. Alexander; B. Altieri; P. Andreani; H. Aussel; F. E. Bauer; S. Berta; A. Bongiovanni; W. N. Brandt; M. Brusa; J. Cepa; A. Cimatti; T. J. Cox; E. Daddi; D. Elbaz; A. Fontana; N. M. Förster Schreiber; R. Genzel; A. Grazian; E. Le Floch; B. Magnelli; V. Mainieri; H. Netzer; R. Nordon; I. Pérez Garcia; A. Poglitsch; P. Popesso; F. Pozzi; L. Riguccini; G. Rodighiero; M. Salvato; M. Sanchez-Portal; E. Sturm; L. J. Tacconi; I....

eye 112

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(Abridged) We study relationships between the SFR and the nuclear properties of X-ray selected AGNs out to z=2.5, using far-IR data in three extragalactic deep fields as part of the PACS Evolutionary Probe (PEP) program. Guided by studies of intrinsic infra-red AGN SEDs, we show that the majority of the FIR emission in AGNs is produced by cold dust heated by star-formation. We uncover characteristic redshift-dependent trends between the mean FIR luminosity (L_fir) and accretion luminosity...
Source: http://arxiv.org/abs/1203.6069v2

Arxiv.org

49 49

Reliable Identification of Compton-thick Quasars at z~2: Spitzer Mid-IR spectroscopy of HDF-oMD49

Sep 18, 2013 09/13

by D. M. Alexander; R. R. Chary; A. Pope; F. E. Bauer; W. N. Brandt; E. Daddi; M. Dickinson; D. Elbaz; N. A. Reddy

eye 49

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Many models that seek to explain the origin of the unresolved X-ray background predict that Compton-thick Active Galactic Nuclei (AGNs) are ubiquitious at high redshift. However, few distant Compton-thick AGNs have been reliably identified to date. Here we present Spitzer-IRS spectroscopy and 3.6-70um photometry of a z=2.2 optically identified AGN (HDF-oMD49) that is formally undetected in the 2Ms Chandra Deep Field-North (CDF-N) survey. The Spitzer-IRS spectrum and spectral energy distribution...
Source: http://arxiv.org/abs/0803.0636v4

Arxiv.org

46 46

Multiwavelength study of massive galaxies at z~2. II. Widespread Compton thick AGN and the concurrent growth of black holes and bulges

Sep 18, 2013 09/13

by E. Daddi; D. M. Alexander; M. Dickinson; R. Gilli; A. Renzini; D. Elbaz; A. Cimatti; R. Chary; D. Frayer; F. E. Bauer; W. N. Brandt; M. Giavalisco; N. A. Grogin; M. Huynh; J. Kurk; M. Mignoli; G. Morrison; A. Pope; S. Ravindranath

eye 46

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Approximately 20-30% of 1.46.2 keV. The stacked X-ray spectrum rises steeply at >10 keV, suggesting that these sources host Compton-thick Active Galactic Nuclei (AGNs) with column densities N_H~10^{24} cm^-2 and an average, unobscured X-ray luminosity L_{2-8 keV}~(1-4)x10^43 erg/s. Their sky density(~3200 deg^-2) and space density (~2.6x10^-4 Mpc^-3) are twice those of X-ray detected AGNs at z~2, and much larger than those of previously-known Compton thick sources at similar redshifts. The...
Source: http://arxiv.org/abs/0705.2832v2

Arxiv.org

9 9.0

The NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-ray Background

Jun 28, 2018 06/18

by F. A. Harrison; J. Aird; F. Civano; G. Lansbury; J. R. Mullaney; D. R. Ballantyne; D. M. Alexander; D. Stern; M. Ajello; D. Barret; F. E. Bauer; M. Balokovic; W. N. Brandt; M. Brightman; S. E. Boggs; F. E. Christensen; A. Comastri; W. W. Craig; A. Del Moro; K. Forster; P. Gandhi; P. Giommi; B. W. Grefenstette; C. J. Hailey; R. C. Hickox; A. Hornstrup; T. Kitaguchi; J. Koglin; B. Luo; K. K. Madsen; P. H. Mao; H. Miyasaka; K. Mori; M. Perri; M. Pivovaroff; S. Puccetti; V. Rana; E. Treister; D....

eye 9

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We present the 3-8 keV and 8-24 keV number counts of active galactic nuclei (AGN) identified in the NuSTAR extragalactic surveys. NuSTAR has now resolved 33-39% of the X-ray background in the 8-24 keV band, directly identifying AGN with obscuring columns up to approximately 1e25 /cm2. In the softer 3-8 keV band the number counts are in general agreement with those measured by XMM-Newton and Chandra over the flux range 5e-15 < S(3 - 8 keV)/(erg/cm2/s) < 1e-12 probed by NuSTAR. In the hard...
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1511.04183

Arxiv.org

5 5.0

A New, Faint Population of X-ray Transients

Jun 30, 2018 06/18

by F. E. Bauer; E. Treister; K. Schawinski; S. Schulze; B. Luo; D. M. Alexander; W. N. Brandt; A. Comastri; F. Forster; R. Gilli; D. A. Kann; K. Maeda; K. Nomoto; M. Paolillo; P. Ranalli; D. P. Schneider; O. Shemmer; M. Tanaka; A. Tolstov; N. Tominaga; P. Tozzi; C. Vignali; J. Wang; Y. Xue; G. Yang

eye 5

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We report on the detection of a remarkable new fast high-energy transient found in the Chandra Deep Field-South, robustly associated with a faint ($m_{\rm R}=27.5$ mag, $z_{\rm ph}$$\sim$2.2) host in the CANDELS survey. The X-ray event is comprised of 115$^{+12}_{-11}$ net 0.3-7.0 keV counts, with a light curve characterised by a $\approx$100 s rise time, a peak 0.3-10 keV flux of $\approx$5$\times$10$^{-12}$ erg s$^{-1}$ cm$^{-2}$, and a power-law decay time slope of $-1.53\pm0.27$. The...
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1702.04422

Arxiv.org

3 3.0

The NuSTAR Serendipitous Survey: The 40 month Catalog and the Properties of the Distant High Energy X-ray Source Population

Jun 29, 2018 06/18

by G. B. Lansbury; D. Stern; J. Aird; D. M. Alexander; C. Fuentes; F. A. Harrison; E. Treister; F. E. Bauer; J. A. Tomsick; M. Balokovic; A. Del Moro; P. Gandhi; M. Ajello; A. Annuar; D. R. Ballantyne; S. E. Boggs; N. Brandt; M. Brightman; C. J. Chen; F. E. Christensen; F. Civano; A. Comastri; W. W. Craig; K. Forster; B. W. Grefenstette; C. J. Hailey; R. Hickox; B. Jiang; H. Jun; M. Koss; S. Marchesi; A. D. Melo; J. R. Mullaney; G. Noirot; S. Schulze; D. J. Walton; L. Zappacosta; W. Zhang

eye 3

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We present the first full catalog and science results for the NuSTAR serendipitous survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ~20Ms of effective exposure time over 331 fields, with an areal coverage of 13 sq deg, and 497 sources detected in total over the 3-24 keV energy range. There are 276 sources with spectroscopic redshifts and classifications, largely resulting from our extensive campaign of ground-based spectroscopic followup....
Topics: Astrophysics, High Energy Astrophysical Phenomena, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1612.06389

Arxiv.org

92 92

Star formation in AGN hosts in GOODS-N

Jul 19, 2013 07/13

by L. Shao; D. Lutz; R. Nordon; R. Maiolino; D. M. Alexander; B. Altieri; P. Andreani; H. Aussel; F. E. Bauer; S. Berta; A. Bongiovanni; W. N. Brandt; M. Brusa; A. Cava; J. Cepa; A. Cimatti; E. Daddi; H. Dominguez-Sanchez; D. Elbaz; N. M. Forster Schreiber; N. Geis; R. Genzel; A. Grazian; C. Gruppioni; G. Magdis; B. Magnelli; V. Mainieri; A. M. Perez Garcia; A. Poglitsch; P. Popesso; F. Pozzi; L. Riguccini; G. Rodighiero; E. Rovilos; A. Saintonge; M. Salvato; M. Sanchez Portal; P. Santini; E....

eye 92

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Sensitive Herschel far-infrared observations can break degeneracies that were inherent to previous studies of star formation in high-z AGN hosts. Combining PACS 100 and 160um observations of the GOODS-N field with 2Msec Chandra data, we detect ~20% of X-ray AGN individually at >3sig. The host far-infrared luminosity of AGN with L2-10~10^43erg/s increases with redshift by an order of magnitude from z=0 to z~1. In contrast, there is little dependence of far-infrared luminosity on AGN...
Source: http://arxiv.org/abs/1005.2562v1

Arxiv.org

4 4.0

A New Population of Compton-Thick AGN Identified Using the Spectral Curvature Above 10 keV

Jun 29, 2018 06/18

by Michael J. Koss; R. Assef; M. Balokovic; D. Stern; P. Gandhi; I. Lamperti; D. M. Alexander; D. R. Ballantyne; F. E. Bauer; S. Berney; W. N. Brandt; A. Comastri; N. Gehrels; F. A. Harrison; G. Lansbury; C. Markwardt; C. Ricci; E. Rivers; K. Schawinski; E. Treister; C. Megan Urry

eye 4

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We present a new metric that uses the spectral curvature (SC) above 10 keV to identify Compton-thick AGN in low-quality Swift BAT X-ray data. Using NuSTAR, we observe nine high SC-selected AGN. We find that high-sensitivity spectra show the majority are Compton-thick (78% or 7/9) and the remaining two are nearly Compton-thick (NH~5-8x10^23 cm^-2). We find the SC_bat and SC_nustar measurements are consistent, suggesting this technique can be applied to future telescopes. We tested the SC method...
Topics: Astrophysics, High Energy Astrophysical Phenomena, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1604.07825

Arxiv.org

44 44

AGN Host Galaxies at z~0.4-1.3 : Bulge-dominated and Lacking Merger-AGN Connection

Sep 19, 2013 09/13

by N. A. Grogin; C. J. Conselice; E. Chatzichristou; D. M. Alexander; F. E. Bauer; A. E. Hornschemeier; S. Jogee; A. M. Koekemoer; V. G. Laidler; M. Livio; R. A. Lucas; M. Paolillo; S. Ravindranath; E. J. Schreier; B. D. Simmons; C. M. Urry

eye 44

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We investigate morphological structure parameters and local environments of distant moderate-luminosity active galactic nucleus (AGN) host galaxies in the overlap between the HST/ACS observations of the Great Observatories Origins Deep Survey (GOODS) and the two Chandra Deep Fields. We compute near-neighbor counts and BViz asymmetry (A) and concentration (C) indices for ~35,500 GOODS/ACS galaxies complete to z_850 ~ 26.6, including the resolved hosts of 322 X-ray-selected AGNs. Distributions of...
Source: http://arxiv.org/abs/astro-ph/0507091v1

Arxiv.org

42 42

Enhanced star formation rates in AGN hosts with respect to inactive galaxies from PEP-Herschel observations

Sep 18, 2013 09/13

by P. Santini; D. J. Rosario; L. Shao; D. Lutz; R. Maiolino; D. M. Alexander; B. Altieri; P. Andreani; H. Aussel; F. E. Bauer; S. Berta; A. Bongiovanni; W. N. Brandt; M. Brusa; J. Cepa; A. Cimatti; E. Daddi; D. Elbaz; A. Fontana; N. M. Forster Schreiber; R. Genzel; A. Grazian; E. Le Floc'h; B. Magnelli; V. Mainieri; R. Nordon; A. M. Perez Garcia; A. Poglitsch; P. Popesso; F. Pozzi; L. Riguccini; G. Rodighiero; M. Salvato; M. Sanchez-Portal; E. Sturm; L. J. Tacconi; I. Valtchanov; S. Wuyts

eye 42

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We compare the average star formation (SF) activity in X-ray selected AGN hosts with mass-matched control inactive galaxies,including star forming and quiescent sources, at 0.510sigma) for bright AGNs. However, when comparing to star forming galaxies only, AGN hosts are broadly consistent with the locus of their `main sequence'. We investigate the relative far-IR luminosity distributions of active and inactive galaxies, and find a higher fraction of PACS detected, hence normal and highly star...
Source: http://arxiv.org/abs/1201.4394v3

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