5
5.0
Feb 14, 2017
02/17
Feb 14, 2017
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
texts
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
5
5.0
Jan 2, 2017
01/17
Jan 2, 2017
by
A. Annuar; D. M. Alexander; P. Gandhi; G. B. Lansbury; D. Asmus; D. R. Ballantyne; F. E. Bauer; S. E. Boggs; P. G. Boorman; W. N. Brandt; M. Brightman; F. E. Christensen; W. W. Craig; D. Farrah; A. D. Goulding; C. J. Hailey; F. A. Harrison; M. J. Koss; S. M. LaMassa; S. S. Murray; C. Ricci; D. J. Rosario; F. Stanley; D. Stern; W. Zhang
texts
eye 5
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NGC 1448 is one of the nearest luminous galaxies ($L_{8-1000\mu m} >$ 10$^{9} L_{\odot}$) to ours ($z$ $=$ 0.00390), and yet the active galactic nucleus (AGN) it hosts was only recently discovered, in 2009. In this paper, we present an analysis of the nuclear source across three wavebands: mid-infrared (MIR) continuum, optical, and X-rays. We observed the source with the Nuclear Spectroscopic Telescope Array (NuSTAR), and combined this data with archival Chandra data to perform broadband...
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1701.00497
3
3.0
Dec 19, 2016
12/16
Dec 19, 2016
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
texts
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
5
5.0
Nov 10, 2016
11/16
Nov 10, 2016
by
B. Luo; W. N. Brandt; Y. Q. Xue; B. Lehmer; D. M. Alexander; F. E. Bauer; F. Vito; G. Yang; A. R. Basu-Zych; A. Comastri; R. Gilli; Q. -S. Gu; A. E. Hornschemeier; A. Koekemoer; T. Liu; V. Mainieri; M. Paolillo; P. Ranalli; P. Rosati; D. P. Schneider; O. Shemmer; I. Smail; M. Sun; P. Tozzi; C. Vignali; J. -X. Wang
texts
eye 5
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We present X-ray source catalogs for the $\approx7$ Ms exposure of the Chandra Deep Field-South (CDF-S), which covers a total area of 484.2 arcmin$^2$. Utilizing WAVDETECT for initial source detection and ACIS Extract for photometric extraction and significance assessment, we create a main source catalog containing 1008 sources that are detected in up to three X-ray bands: 0.5-7.0 keV, 0.5-2.0 keV, and 2-7 keV. A supplementary source catalog is also provided including 47 lower-significance...
Topics: Astrophysics, High Energy Astrophysical Phenomena, Cosmology and Nongalactic Astrophysics,...
Source: http://arxiv.org/abs/1611.03501
9
9.0
Sep 15, 2016
09/16
Sep 15, 2016
by
C. Ricci; R. J. Assef; D. Stern; R. Nikutta; D. M. Alexander; D. Asmus; D. R. Ballantyne; F. E. Bauer; A. W. Blain; S. Boggs; P. G. Boorman; W. N. Brandt; M. Brightman; C. S. Chang; C. -T. J. Chen; F. E. Christensen; A. Comastri; W. W. Craig; T. Díaz-Santos; P. R. Eisenhardt; D. Farrah; P. Gandhi; C. J. Hailey; F. A. Harrison; H. D. Jun; M. J. Koss; S. LaMassa; G. B. Lansbury; C. B. Markwardt; M. Stalevski; F. Stanley; E. Treister; C. -W. Tsai; D. J. Walton; J. W. Wu; L. Zappacosta; W. W. Zhang
texts
eye 9
favorite 0
comment 0
Hot, Dust-Obscured Galaxies (Hot DOGs), selected from the WISE all sky infrared survey, host some of the most powerful Active Galactic Nuclei (AGN) known, and might represent an important stage in the evolution of galaxies. Most known Hot DOGs are at $z> 1.5$, due in part to a strong bias against identifying them at lower redshift related to the selection criteria. We present a new selection method that identifies 153 Hot DOG candidates at $z\sim 1$, where they are significantly brighter and...
Topics: Astrophysics, High Energy Astrophysical Phenomena, Cosmology and Nongalactic Astrophysics,...
Source: http://arxiv.org/abs/1609.04808
4
4.0
Apr 26, 2016
04/16
Apr 26, 2016
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
texts
eye 4
favorite 0
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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
4
4.0
Feb 19, 2016
02/16
Feb 19, 2016
by
Y. Q. Xue; B. Luo; W. N. Brandt; D. M. Alexander; F. E. Bauer; B. D. Lehmer; G. Yang
texts
eye 4
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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
Topics: Astrophysics, High Energy Astrophysical Phenomena, Cosmology and Nongalactic Astrophysics,...
Source: http://arxiv.org/abs/1602.06299
14
14
Nov 13, 2015
11/15
Nov 13, 2015
by
J. R. Mullaney; A. Del-Moro; J. Aird; D. M. Alexander; F. M. Civano; R. C. Hickox; G. B. Lansbury; M. Ajello; R. Assef; D. R. Ballantyne; M. Balokovic; F. E. Bauer; W. N. Brandt; S. E. Boggs; M. Brightman; F. E. Christensen; A. Comastri; W. W. Craig; M. Elvis; K. Forster; P. Gandhi; B. W. Grefenstette; C. J. Hailey; F. A. Harrison; M. Koss; S. M. LaMassa; B. Luo; K. K. Madsen; S. Puccetti; C. Saez; D. Stern; E. Treister; C. M. Urry; D. R. Wik; L. Zappacosta; W. Zhang
texts
eye 14
favorite 1
comment 0
We present initial results and the source catalog from the NuSTAR survey of the Extended Chandra Deep Field South (hereafter, ECDFS) - currently the deepest contiguous component of the NuSTAR extragalactic survey program. The survey covers the full ~30 arcmin x 30 arcmin area of this field to a maximum depth of ~360 ks (~220 ks when corrected for vignetting at 3-24 keV), reaching sensitivity limits of ~1.3 x 10^-14 erg/cm2/s (3-8 keV), ~3.4 x 10^-14 erg/cm2/s (8-24 keV) and ~3.0 x 10^-14...
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1511.04186
9
9.0
Nov 13, 2015
11/15
Nov 13, 2015
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....
texts
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
10
10.0
Nov 13, 2015
11/15
Nov 13, 2015
by
J. Aird; D. M. Alexander; D. R. Ballantyne; F. Civano; A. Del-Moro; R. C. Hickox; G. B. Lansbury; J. R. Mullaney; F. E. Bauer; W. N. Brandt; A. Comastri; A. C. Fabian; P. Gandhi; F. A. Harrison; B. Luo; D. Stern; E. Treister; L. Zappacosta; M. Ajello; R. Assef; S. E. Boggs; M. Brightman; F. E. Christensen; W. W. Craig; M. Elvis; K. Forster; M. Balokovic; B. W. Grefenstette; C. J. Hailey; M. Koss; S. M. LaMassa; K. K. Madsen; S. Puccetti; C. Saez; C. M. Urry; D. R. Wik; W. Zhang
texts
eye 10
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comment 0
We present the first direct measurements of the rest-frame 10-40 keV X-ray luminosity function (XLF) of Active Galactic Nuclei (AGNs) based on a sample of 94 sources at 0.1 < z
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1511.04184
7
7.0
Nov 13, 2015
11/15
Nov 13, 2015
by
F. Civano; R. C. Hickox; S. Puccetti; A. Comastri; J. R. Mullaney; L. Zappacosta; S. M. LaMassa; J. Aird; D. M. Alexander; D. R. Ballantyne; F. E. Bauer; W. N. Brandt; S. E. Boggs; F. E. Christensen; W. W. Craig; A. Del-Moro; M. Elvis; K. Forster; P. Gandhi; B. W. Grefenstette; C. J. Hailey; F. A. Harrison; G. B. Lansbury; B. Luo; K. Madsen; C. Saez; D. Stern; E. Treister; M. C. Urry; D. R. Wik; W. Zhang
texts
eye 7
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comment 0
To provide the census of the sources contributing to the X-ray background peak above 10 keV, NuSTAR is performing extragalactic surveys using a three-tier "wedding cake" approach. We present the NuSTAR survey of the COSMOS field, the medium sensitivity and medium area tier, covering 1.7 deg2 and overlapping with both Chandra and XMM-Newton data. This survey consists of 121 observations for a total exposure of ~3 Ms. To fully exploit these data, we developed a new detection strategy,...
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1511.04185
8
8.0
Nov 11, 2015
11/15
Nov 11, 2015
by
A. Marinucci; S. Bianchi; G. Matt; D. M. Alexander; M. Balokovic; F. E. Bauer; W. N. Brandt; P. Gandhi; M. Guainazzi; F. A. Harrison; K. Iwasawa; M. Koss; K. K. Madsen; F. Nicastro; S. Puccetti; C. Ricci; D. Stern; D. J. Walton
texts
eye 8
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We present a NuSTAR and XMM-Newton monitoring campaign in 2014/2015 of the Compton-thick Seyfert 2 galaxy, NGC 1068. During the August 2014 observation, we detect with NuSTAR a flux excess above 20 keV ($32\pm6 \%$) with respect to the December 2012 observation and to a later observation performed in February 2015. We do not detect any spectral variation below 10 keV in the XMM-Newton data. The transient excess can be explained by a temporary decrease of the column density of the obscuring...
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1511.03503
3
3.0
Oct 30, 2015
10/15
Oct 30, 2015
by
C. M. Harrison; D. M. Alexander; J. R. Mullaney; J. P. Stott; A. M. Swinbank; V. Arumugam; F. E. Bauer; R. G. Bower; A. J. Bunker; R. M. Sharples
texts
eye 3
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We present the first results from the KMOS AGN Survey at High redshift (KASHz), a VLT/KMOS integral-field spectroscopic survey of z>0.6 AGN. We present galaxy-integrated spectra of 89 X-ray AGN (Lx=10^42-10^45 erg/s), for which we observed [O III] (z=1.1-1.7) or Halpha emission (z=0.6-1.1). The targets have X-ray luminosities representative of the parent AGN population and we explore the emission-line luminosities as a function of X-ray luminosity. For the [O III] targets, ~50 per cent have...
Topics: Astrophysics, Astrophysics of Galaxies, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1511.00008
6
6.0
Oct 15, 2015
10/15
Oct 15, 2015
by
S. Puccetti; A. Comastri; F. E. Bauer; W. N. Brandt; F. Fiore; F. A. Harrison; B. Luo; D. Stern; C. M. Urry; D. M. Alexander; A. Annuar; P. Arévalo; M. Baloković; S. E. Boggs; M. Brightman; F. E. Christensen; W. W. Craig; P. Gandhi; C. J. Hailey; M. J. Koss; S. La Massa; A. Marinucci; C. Ricci; D. J. Walton; L. Zappacosta; W. Zhang
texts
eye 6
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We present a broad-band (~0.3-70 keV) spectral and temporal analysis of NuSTAR observations of the luminous infrared galaxy NGC 6240, combined with archival Chandra, XMM-Newton and BeppoSAX data. NGC 6240 is a galaxy in a relatively early merger state with two distinct nuclei separated by ~1."5. Previous Chandra observations have resolved the two nuclei, showing that they are both active and obscured by Compton-thick material. Although they cannot be resolved by NuSTAR, thanks to the...
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1510.04477
20
20
Sep 10, 2015
09/15
Sep 10, 2015
by
A. Annuar; P. Gandhi; D. M. Alexander; G. B. Lansbury; P. Arévalo; D. R. Ballantyne; M. Baloković; F. E. Bauer; S. E. Boggs; W. N. Brandt; M. Brightman; F. E. Christensen; W. W. Craig; A. Del Moro; C. J. Hailey; F. A. Harrison; R. C. Hickox; G. Matt; S. Puccetti; C. Ricci; J. R. Rigby; D. Stern; D. J. Walton; L. Zappacosta; W. Zhang
texts
eye 20
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We present two NuSTAR observations of the local Seyfert 2 active galactic nucleus (AGN) and an ultraluminous X-ray source (ULX) candidate in NGC 5643. Together with archival data from Chandra, XMM-Newton and Swift-BAT, we perform a high-quality broadband spectral analysis of the AGN over two decades in energy ($\sim$0.5-100 keV). Previous X-ray observations suggested that the AGN is obscured by a Compton-thick (CT) column of obscuring gas along our line-of-sight. However, the lack of...
Topics: High Energy Astrophysical Phenomena, Astrophysics
Source: http://arxiv.org/abs/1509.03322
16
16
Jun 16, 2015
06/15
Jun 16, 2015
by
G. B. Lansbury; P. Gandhi; D. M. Alexander; R. J. Assef; J. Aird; A. Annuar; D. R. Ballantyne; M. Balokovic; F. E. Bauer; S. E. Boggs; W. N. Brandt; M. Brightman; F. E. Christensen; F. Civano; A. Comastri; W. W. Craig; A. Del Moro; B. W. Grefenstette; C. J. Hailey; F. A. Harrison; R. C. Hickox; M. Koss; S. M. LaMassa; B. Luo; S. Puccetti; D. Stern; E. Treister; C. Vignali; L. Zappacosta; W. W. Zhang
texts
eye 16
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The intrinsic column density (NH) distribution of quasars is poorly known. At the high obscuration end of the quasar population and for redshifts z 1.5e24 cm^-2) type 2 quasars (CTQSO2s); five new NuSTAR observations are reported herein, and four have been previously published. The candidate CTQSO2s lie at z ~ 90 net source counts at 8-24 keV). For these NuSTAR-detected sources direct (i.e., X-ray spectral) constraints on the intrinsic AGN properties are feasible, and we measure column...
Topics: High Energy Astrophysical Phenomena, Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1506.05120
12
12
Apr 13, 2015
04/15
Apr 13, 2015
by
A. Del Moro; D. M. Alexander; F. E. Bauer; E. Daddi; D. D. Kocevski; D. H. McIntosh; F. Stanley; W. N. Brandt; D. Elbaz; C. M. Harrison; B. Luo; J. R. Mullaney; Y. Q. Xue
texts
eye 12
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We present the infrared (IR) and X-ray properties of a sample of 33 mid-IR luminous quasars ($\nu$L(6 micron)>6x10$^{44}$ erg/s) at redshift z~1-3, identified through detailed spectral energy distribution analyses of distant star-forming galaxies, using the deepest IR data from Spitzer and Herschel in the GOODS-Herschel fields. The aim is to constrain the fraction of obscured, and Compton-thick (CT, N$_H$>1.5x10$^{24}$ cm$^{-2}$) quasars at the peak era of nuclear and star-formation...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1504.03329
11
11
Apr 2, 2015
04/15
Apr 2, 2015
by
C. Saez; B. D. Lehmer; F. E. Bauer; D. Stern; A. Gonzales; I. Rreza; D. M. Alexander; Y. Matsuda; J. E. Geach; F. A. Harrison; T. Havashino
texts
eye 11
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We present VLT VIMOS, Keck DEIMOS and Keck LRIS multi-object spectra of 367 sources in the field of the z ~ 3.09 protocluster SSA22. Sources are spectroscopically classified via template matching, allowing new identifications for 206 extragalactic sources, including 36 z > 2 Lyman-break galaxies (LBGs) and Lyman-\alpha\ emitters (LAEs), 8 protocluster members, and 94 X-ray sources from the ~ 400 ks Chandra deep survey of SSA22. Additionally, in the area covered by our study, we have...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1504.00737
4
4.0
Oct 24, 2014
10/14
Oct 24, 2014
by
G. Yang; Y. Q. Xue; B. Luo; W. N. Brandt; D. M. Alexander; F. E. Bauer; W. Cui; X. Kong; B. D. Lehmer; J. -X. Wang; X. -B. Wu; F. Yuan; Y. -F. Yuan; H. Y. Zhou
texts
eye 4
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We derive photometric redshifts (\zp) for sources in the entire ($\sim0.4$ deg$^2$) Hawaii-Hubble Deep Field-North (\hdfn) field with the EAzY code, based on point spread function-matched photometry of 15 broad bands from the ultraviolet (\bandu~band) to mid-infrared (IRAC 4.5 $\mu$m). Our catalog consists of a total of 131,678 sources. We evaluate the \zp~quality by comparing \zp~with spectroscopic redshifts (\zs) when available, and find a value of normalized median absolute deviation...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1410.6860
3
3.0
Oct 15, 2014
10/14
Oct 15, 2014
by
C. M. Harrison; A. P. Thomson; D. M. Alexander; F. E. Bauer; A. C. Edge; M. T. Hogan; J. R. Mullaney; A. M. Swinbank
texts
eye 3
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comment 0
We present multi-frequency (1-8 GHz) VLA data, combined with VIMOS IFU data and HST imaging, of a z=0.085 radio-quiet type 2 quasar (with L(1.4GHz)~5e23 W/Hz and L(AGN)~2e45 erg/s). Due to the morphology of its emission-line region, the target (J1430+1339) has been referred to as the Teacup AGN in the literature. We identify "bubbles" of radio emission that are extended ~10-12 kpc to both the east and west of the nucleus. The edge of the brighter eastern bubble is co-spatial with an...
Topics: Astrophysics of Galaxies, High Energy Astrophysical Phenomena, Astrophysics, Cosmology and...
Source: http://arxiv.org/abs/1410.4198
8
8.0
Sep 17, 2014
09/14
Sep 17, 2014
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;...
texts
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
6
6.0
Aug 22, 2014
08/14
Aug 22, 2014
by
M. Baloković; A. Comastri; F. A. Harrison; D. M. Alexander; D. R. Ballantyne; F. E. Bauer; S. E. Boggs; W. N. Brandt; M. Brightman; F. E. Christensen; W. W. Craig; A. Del Moro; P. Gandhi; C. J. Hailey; M. Koss; G. B. Lansbury; B. Luo; G. M. Madejski; A. Marinucci; G. Matt; C. B. Markwardt; S. Puccetti; C. S. Reynolds; G. Risaliti; E. Rivers; D. Stern; D. J. Walton; W. W. Zhang
texts
eye 6
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We present X-ray spectral analyses for three Seyfert 2 active galactic nuclei, NGC 424, NGC 1320, and IC 2560, observed by NuSTAR in the 3-79 keV band. The high quality hard X-ray spectra allow detailed modeling of the Compton reflection component for the first time in these sources. Using quasi-simultaneous NuSTAR and Swift/XRT data, as well as archival XMM-Newton data, we find that all three nuclei are obscured by Compton-thick material with column densities in excess of ~5 x $10^{24}$...
Topics: Astrophysics of Galaxies, High Energy Astrophysical Phenomena, Astrophysics
Source: http://arxiv.org/abs/1408.5414
8
8.0
Aug 15, 2014
08/14
Aug 15, 2014
by
B. Luo; W. N. Brandt; D. M. Alexander; D. Stern; S. H. Teng; P. Arévalo; F. E. Bauer; S. E. Boggs; F. E. Christensen; A. Comastri; W. W. Craig; D. Farrah; P. Gandhi; C. J. Hailey; F. A. Harrison; M. Koss; P. Ogle; S. Puccetti; C. Saez; A. E. Scott; D. J. Walton; W. W. Zhang
texts
eye 8
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comment 0
We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z=0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z 330 times weaker than expected for typical quasars. Our results from a pilot NuSTAR study of two low-redshift BAL quasars, a Chandra stacking analysis of a sample of high-redshift BAL quasars, and a NuSTAR spectral analysis of the local BAL quasar Mrk 231 have already suggested the existence...
Topics: Astrophysics of Galaxies, High Energy Astrophysical Phenomena, Astrophysics
Source: http://arxiv.org/abs/1408.3633
8
8.0
Jul 7, 2014
07/14
Jul 7, 2014
by
P. Gandhi; G. B. Lansbury; D. M. Alexander; D. Stern; P. Arévalo; D. R. Ballantyne; M. Baloković; F. E. Bauer; S. E. Boggs; W. N. Brandt; M. Brightman; F. E. Christensen; A. Comastri; W. W. Craig; A. Del Moro; M. Elvis; A. C. Fabian; C. J. Hailey; F. A. Harrison; R. C. Hickox; M. Koss; S. M. LaMassa; B. Luo; G. M. Madejski; A. F. Ptak; S. Puccetti; S. H. Teng; C. M. Urry; D. J. Walton; W. W. Zhang
texts
eye 8
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We present Nustar 3-40 keV observations of the optically selected Type 2 quasar (QSO2) SDSS J1034+6001 or Mrk 34. The high-quality hard X-ray spectrum and archival XMM-Newton data can be fitted self-consistently with a reflection-dominated continuum and strong Fe Kalpha fluorescence line with equivalent-width >1 keV. Prior X-ray spectral fitting below 10 keV showed the source to be consistent with being obscured by Compton-thin column densities of gas along the line-of-sight, despite...
Topics: Astrophysics of Galaxies, High Energy Astrophysical Phenomena, Astrophysics, Cosmology and...
Source: http://arxiv.org/abs/1407.1844
8
8.0
May 8, 2014
05/14
May 8, 2014
by
B. D Lehmer; M. Berkeley; A. Zezas; D. M. Alexander; A. Basu-Zych; F. E. Bauer; W. N. Brandt; T. Fragos; A. E. Hornschemeier; V. Kalogera; A. Ptak; G. R. Sivakoff; P. Tzanavaris; M. Yukita
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eye 8
favorite 0
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We present direct constraints on how the formation of low-mass X-ray binary (LMXB) populations in galactic fields depends on stellar age. In this pilot study, we utilize Chandra and Hubble Space Telescope (HST) data to detect and characterize the X-ray point source populations of three nearby early-type galaxies: NGC 3115, 3379, and 3384. The luminosity-weighted stellar ages of our sample span 3-10 Gyr. X-ray binary population synthesis models predict that the field LMXBs associated with...
Topics: Astrophysics of Galaxies, High Energy Astrophysical Phenomena, Astrophysics
Source: http://arxiv.org/abs/1405.2069
7
7.0
Mar 11, 2014
03/14
Mar 11, 2014
by
A. Del Moro; J. R. Mullaney; D. M. Alexander; A. Comastri; F. E. Bauer; E. Treister; D. Stern; F. Civano; P. Ranalli; C. Vignali; J. A. Aird; D. R. Ballantyne; M. Baloković; S. E. Boggs; W. N. Brandt; F. E. Christensen; W. W. Craig; P. Gandhi; R. Gilli; C. J. Hailey; F. A. Harrison; R. C. Hickox; S. M. LaMassa; G. B. Lansbury; B. Luo; S. Puccetti; M. Urry; W. W. Zhang
texts
eye 7
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We report NuSTAR observations of NuSTAR J033202-2746.8, a heavily obscured, radio-loud quasar detected in the Extended Chandra Deep Field-South, the deepest layer of the NuSTAR extragalactic survey (~400 ks, at its deepest). NuSTAR J033202-2746.8 is reliably detected by NuSTAR only at E>8 keV and has a very flat spectral slope in the NuSTAR energy band (Gamma=0.55^{+0.62}_{-0.64}; 3-30 keV). Combining the NuSTAR data with extremely deep observations by Chandra and XMM-Newton (4 Ms and 3 Ms,...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1403.2491
6
6.0
Feb 19, 2014
02/14
Feb 19, 2014
by
Stacy H. Teng; W. N. Brandt; F. A. Harrison; B. Luo; D. M. Alexander; F. E. Bauer; S. E. Boggs; F. E. Christensen; A. Comastri; W. W. Craig; A. C. Fabian; D. Farrah; F. Fiore; P. Gandhi; B. W. Grefenstette; C. J. Hailey; R. C. Hickox; K. K. Madsen; A. F. Ptak; J. R. Rigby; G. Risaliti; C. Saez; D. Stern; S. Veilleux; D. J. Walton; D. R. Wik; W. W. Zhang
texts
eye 6
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We present high-energy (3--30 keV) {\it NuSTAR} observations of the nearest quasar, the ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5--8 keV) data from {\it Chandra}. The source was detected, though at much fainter levels than previously reported, likely due to contamination in the large apertures of previous non-focusing hard X-ray telescopes. The full band (0.5--30 keV) X-ray spectrum suggests the active galactic nucleus...
Topics: High Energy Astrophysical Phenomena, Astrophysics
Source: http://arxiv.org/abs/1402.4811
9
9.0
Feb 11, 2014
02/14
Feb 11, 2014
by
G. B. Lansbury; D. M. Alexander; A. Del Moro; P. Gandhi; R. J. Assef; D. Stern; J. Aird; D. R. Ballantyne; M. Balokovic; F. E. Bauer; S. E. Boggs; W. N. Brandt; F. E. Christensen; W. W. Craig; M. Elvis; B. W. Grefenstette; C. J. Hailey; F. A. Harrison; R. C. Hickox; M. Koss; S. M. LaMassa; B. Luo; J. R. Mullaney; S. H. Teng; C. M. Urry; W. W. Zhang
texts
eye 9
favorite 0
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We present NuSTAR hard X-ray (3-79 keV) observations of three Type 2 quasars at z ~ 0.4-0.5, optically selected from the Sloan Digital Sky Survey (SDSS). Although the quasars show evidence for being heavily obscured Compton-thick systems on the basis of the 2-10 keV to [OIII] luminosity ratio and multiwavelength diagnostics, their X-ray absorbing column densities (N_H) are poorly known. In this analysis: (1) we study X-ray emission at >10 keV, where X-rays from the central black hole are...
Topics: Astrophysics of Galaxies, High Energy Astrophysical Phenomena, Astrophysics
Source: http://arxiv.org/abs/1402.2666
112
112
Feb 5, 2013
02/13
Feb 5, 2013
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....
texts
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
49
49
Oct 26, 2012
10/12
Oct 26, 2012
by
F. Vito; C. Vignali; R. Gilli; A. Comastri; K. Iwasawa; W. N. Brandt; D. M. Alexander; M. Brusa; B. Lehmer; F. E. Bauer; D. P. Schneider; Y. Q. Xue; B. Luo
texts
eye 49
favorite 0
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We present results from a spectral analysis of a sample of high-redshift (z>3) X-ray selected AGN in the 4 Ms Chandra Deep Field South (CDF-S), the deepest X-ray survey to date. The sample is selected using the most recent spectroscopic and photometric information available in this field. It consists of 34 sources with median redshift z=3.7, 80 median net counts in the 0.5-7 keV band and median rest-frame absorption-corrected luminosity $L_{2-10 \rmn{keV}}\approx1.5\times10^{44}\rmn{erg}...
Source: http://arxiv.org/abs/1209.4193v2
49
49
Oct 9, 2012
10/12
Oct 9, 2012
by
A. Del Moro; D. M. Alexander; J. R. Mullaney; E. Daddi; M. Pannella; F. E. Bauer; A. Pope; M. Dickinson; D. Elbaz; P. D. Barthel; M. A. Garrett; W. N. Brandt; V. Charmandaris; R. R. Chary; K. Dasyra; R. Gilli; R. C. Hickox; H. S. Hwang; R. J. Ivison; S. Juneau; E. Le Floc'h; B. Luo; G. E. Morrison; E. Rovilos; M. T. Sargent; Y. Q. Xue
texts
eye 49
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We present here a new spectral energy distribution (SED) fitting approach that we adopt to select radio-excess sources amongst distant star-forming galaxies in the GOODS-Herschel (North) field and to reveal the presence of hidden, highly obscured AGN. Through extensive SED analysis of 458 galaxies with radio 1.4 GHz and mid-IR 24 um detections using some of the deepest Chandra X-ray, Spitzer and Herschel infrared, and VLA radio data available to date, we have robustly identified a sample of 51...
Source: http://arxiv.org/abs/1210.2521v1
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58
Sep 24, 2012
09/12
Sep 24, 2012
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
texts
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
36
36
Sep 3, 2012
09/12
Sep 3, 2012
by
Y. Q. Xue; S. X. Wang; W. N. Brandt; B. Luo; D. M. Alexander; F. E. Bauer; A. Comastri; A. C. Fabian; R. Gilli; B. D. Lehmer; D. P. Schneider; C. Vignali; M. Young
texts
eye 36
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Using the 4 Ms Chandra Deep Field-South (CDF-S) survey, we have identified a sample of 6845 X-ray undetected galaxies that dominates the unresolved ~ 20-25% of the 6-8 keV cosmic X-ray background (XRB). This sample was constructed by applying mass and color cuts to sources from a parent catalog based on GOODS-South HST z-band imaging of the central 6'-radius area of the 4 Ms CDF-S. The stacked 6-8 keV detection is significant at the 3.9 sigma level, but the stacked emission was not detected in...
Source: http://arxiv.org/abs/1209.0467v1
59
59
May 8, 2012
05/12
May 8, 2012
by
A. D. Goulding; D. M. Alexander; F. E. Bauer; W. R. Forman; R. C. Hickox; C. Jones; J. R. Mullaney; M. Trichas
texts
eye 59
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We explore the origin of mid-infrared (mid-IR) dust extinction in all 20 nearby (z < 0.05) bona-fide Compton-thick (N_H > 1.5 x 10^24 cm^-2) AGN with hard energy (E > 10 keV) X-ray spectral measurements. We accurately measure the silicate absorption features at lambda~9.7um in archival low-resolution (R~57-127) Spitzer Infrared Spectrograph (IRS) spectroscopy, and show that only a minority (~45%) of nearby Compton-thick AGN have strong Si-absorption features (S_9.7 =...
Source: http://arxiv.org/abs/1205.1800v1
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50
Apr 9, 2012
04/12
Apr 9, 2012
by
B. D. Lehmer; Y. Q. Xue; W. N. Brandt; D. M. Alexander; F. E. Bauer; M. Brusa; A. Comastri; R. Gilli; A. E. Hornschemeier; B. Luo; M. Paolillo; A. Ptak; O. Shemmer; D. P. Schneider; P. Tozzi; C. Vignali
texts
eye 50
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We present 0.5-2 keV, 2-8 keV, 4-8 keV, and 0.5-8 keV cumulative and differential number counts (logN-logS) measurements for the recently completed ~4 Ms Chandra Deep Field-South (CDF-S) survey, the deepest X-ray survey to date. We implement a new Bayesian approach, which allows reliable calculation of number counts down to flux limits that are factors of ~1.9-4.3 times fainter than the previously deepest number-counts investigations. In the soft band, the most sensitive bandpass in our...
Source: http://arxiv.org/abs/1204.1977v1
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42
Mar 23, 2012
03/12
Mar 23, 2012
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
texts
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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47
Jan 20, 2012
01/12
Jan 20, 2012
by
M. Young; W. N. Brandt; Y. Q. Xue; M. Paolillo; D. M. Alexander; F. E. Bauer; B. D. Lehmer; B. Luo; O. Shemmer; D. P. Schneider; C. Vignali
texts
eye 47
favorite 1
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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...
Source: http://arxiv.org/abs/1201.4391v1
58
58
Sep 7, 2011
09/11
Sep 7, 2011
by
J. R. Mullaney; M. Pannella; E. Daddi; D. M. Alexander; D. Elbaz; R. C. Hickox; F. Bournaud; B. Altieri; H. Aussel; D. Coia; H. Dannerbauer; K. Dasyra; M. Dickinson; H. S. Hwang; J. Kartaltepe; R. Leiton; G. Magdis; B. Magnelli; P. Popesso; I. Valtchanov; F. E. Bauer; W. N. Brandt; A. Del Moro; D. J. Hanish; R. J. Ivison; S. Juneau; B. Luo; D. Lutz; M. T. Sargent; D. Scott; Y. Q. Xue
texts
eye 58
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We present a study of the infrared properties of X-ray selected, moderate luminosity (Lx=10^{42}-10^{44}ergs/s) active galactic nuclei (AGNs) up to z~3, to explore the links between star formation in galaxies and accretion onto their central black holes. We use 100um and 160um fluxes from GOODS-Herschel -the deepest survey yet undertaken by the Herschel telescope- and show that in >94 per cent of cases these fluxes are dominated by the host. We find no evidence of any correlation between the...
Source: http://arxiv.org/abs/1106.4284v3
51
51
Aug 16, 2011
08/11
Aug 16, 2011
by
D. A. Rafferty; W. N. Brandt; D. M. Alexander; Y. Q. Xue; F. E. Bauer; B. D. Lehmer; B. Luo; C. Papovich
texts
eye 51
favorite 0
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We present an analysis of deep multiwavelength data for z ~ 0.3-3 starburst galaxies selected by their 70 um emission in the Extended-Chandra Deep Field-South and Extended Groth Strip. We identify active galactic nuclei (AGNs) in these infrared sources through their X-ray emission and quantify the fraction that host an AGN. We find that the fraction depends strongly on both the mid-infrared color and rest-frame mid-infrared luminosity of the source, rising to ~ 50-70% at the warmest colors and...
Source: http://arxiv.org/abs/1108.3229v1
138
138
Jul 15, 2011
07/11
Jul 15, 2011
by
B. Luo; W. N. Brandt; Y. Q. Xue; D. M. Alexander; M. Brusa; F. E. Bauer; A. Comastri; A. C. Fabian; R. Gilli; B. D. Lehmer; D. A. Rafferty; D. P. Schneider; C. Vignali
texts
eye 138
favorite 0
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(abridged) We identify a numerically significant population of heavily obscured AGNs at z~0.5-1 in the Chandra Deep Field-South (CDF-S) and Extended Chandra Deep Field-South by selecting 242 X-ray undetected objects with infrared-based star formation rates (SFRs) substantially higher (a factor of 3.2 or more) than their SFRs determined from the UV after correcting for dust extinction. An X-ray stacking analysis of 23 candidates in the central CDF-S region using the 4 Ms Chandra data reveals a...
Source: http://arxiv.org/abs/1107.3148v1
52
52
Jun 7, 2011
06/11
Jun 7, 2011
by
D. M. Alexander; F. E. Bauer; W. N. Brandt; E. Daddi; R. C. Hickox; B. D. Lehmer; B. Luo; Y. Q. Xue; M. Young; A. Comastri; A. Del Moro; A. C. Fabian; R. Gilli; A. D. Goulding; V. Mainieri; J. R. Mullaney; M. Paolillo; D. A. Rafferty; D. P. Schneider; O. Shemmer; C. Vignali
texts
eye 52
favorite 0
comment 0
We use the 4Ms CDF-S survey to place direct X-ray constraints on the ubiquity of z~2 heavily obscured AGNs in K 1E43 erg/s) heavily obscured and Compton-thick AGNs at z~2. Our space-density constraints are conservative lower limits but they are already consistent with the range of predictions from X-ray background models.
Source: http://arxiv.org/abs/1106.1443v1
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57
May 27, 2011
05/11
May 27, 2011
by
Y. Q. Xue; B. Luo; W. N. Brandt; F. E. Bauer; B. D. Lehmer; P. S. Broos; D. P. Schneider; D. M. Alexander; M. Brusa; A. Comastri; A. C. Fabian; R. Gilli; G. Hasinger; A. E. Hornschemeier; A. Koekemoer; T. Liu; V. Mainieri; M. Paolillo; D. A. Rafferty; P. Rosati; O. Shemmer; J. D. Silverman; I. Smail; P. Tozzi; C. Vignali
texts
eye 57
favorite 1
comment 0
[abridged] We present point-source catalogs for the 4Ms Chandra Deep Field-South (CDF-S), which is the deepest Chandra survey to date and covers an area of 464.5 arcmin^2. We provide a main source catalog, which contains 740 X-ray point sources that are detected with wavdetect at a false-positive probability threshold of 1E-5 and also satisfy a binomial-probability source-selection criterion of P
Source: http://arxiv.org/abs/1105.5643v1
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41
Sep 20, 2010
09/10
Sep 20, 2010
by
B. D. Lehmer; D. M. Alexander; F. E. Bauer; W. N. Brandt; A. D. Goulding; L. P. Jenkins; A. Ptak; T. P. Roberts
texts
eye 41
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We present new Chandra observations that complete a sample of seventeen (17) luminous infrared galaxies (LIRGs) with D < 60 Mpc and low Galactic column densities of N_H < 5 X 10^20 cm^-2. The LIRGs in our sample have total infrared (8-1000um) luminosities in the range of L_IR ~ (1-8) X 10^11 L_sol. The high-resolution imaging and X-ray spectral information from our Chandra observations allow us to measure separately X-ray contributions from active galactic nuclei (AGNs) and normal galaxy...
Source: http://arxiv.org/abs/1009.3943v1
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45
Sep 10, 2010
09/10
Sep 10, 2010
by
J. D. Silverman; V. Mainieri; M. Salvato; G. Hasinger; J. Bergeron; P. Capak; G. Szokoly; A. Finoguenov; R. Gilli; P. Rosati; P. Tozzi; C. Vignali; D. M. Alexander; W. N. Brandt; B. D. Lehmer; B. Luo; D. Rafferty; Y. Q. Xue; I. Balestra; F. E. Bauer; M. Brusa; A. Comastri; J. Kartaltepe; A. M. Koekemoer; T. Miyaji; D. P. Schneider; E. Treister; L. Wisotski; M. Schramm
texts
eye 45
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We present the results of a program to acquire high-quality optical spectra of X-ray sources detected in the E-CDF-S and its central area. New spectroscopic redshifts are measured for 283 counterparts to Chandra sources with deep exposures (t~2-9 hr per pointing) using multi-slit facilities on both the VLT and Keck thus bringing the total number of spectroscopically-identified X-ray sources to over 500 in this survey field. We provide a comprehensive catalog of X-ray sources detected in the...
Source: http://arxiv.org/abs/1009.1923v1
73
73
Jul 8, 2010
07/10
Jul 8, 2010
by
Y. Q. Xue; W. N. Brandt; B. Luo; D. A. Rafferty; D. M. Alexander; F. E. Bauer; B. D. Lehmer; D. P. Schneider; J. D. Silverman
texts
eye 73
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[Abridged] We extend color-magnitude relations for moderate-luminosity X-ray AGN hosts and non-AGN galaxies through the galaxy formation epoch in the Chandra Deep Fields. We utilized analyses of color-magnitude diagrams (CMDs) to assess the role of moderate-luminosity AGNs in galaxy evolution. First, we confirm some previous results and extend them to higher redshifts, e.g., there is no apparent color bimodality for AGN hosts from z~0-2, but non-AGN galaxy color bimodality exists up to z~3;...
Source: http://arxiv.org/abs/1007.1453v1
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35
Jun 23, 2010
06/10
Jun 23, 2010
by
S. I. Raimundo; A. C. Fabian; F. E. Bauer; D. M. Alexander; W. N. Brandt; B. Luo; R. V. Vasudevan; Y. Q. Xue
texts
eye 35
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The presence of absorbing gas around the central engine of Active Galactic Nuclei (AGN) is a common feature of these objects. Recent work has looked at the effect of the dust component of the gas, and how it enhances radiation pressure such that dusty gas can have a lower effective Eddington limit than ionised gas. In this work, we use multi-wavelength data and X-ray spectra from the 2 Ms exposures of the Chandra Deep Field North and Chandra Deep Field South surveys, to characterise the AGN in...
Source: http://arxiv.org/abs/1006.4436v1
92
92
May 14, 2010
05/10
May 14, 2010
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....
texts
eye 92
favorite 0
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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
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48
Mar 2, 2010
03/10
Mar 2, 2010
by
B. Luo; W. N. Brandt; Y. Q. Xue; M. Brusa; D. M. Alexander; F. E. Bauer; A. Comastri; A. Koekemoer; B. D. Lehmer; V. Mainieri; D. A. Rafferty; D. P. Schneider; J. D. Silverman; C. Vignali
texts
eye 48
favorite 0
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[Abridged] We present reliable multiwavelength identifications and high-quality photometric redshifts for the 462 X-ray sources in the ~2 Ms Chandra Deep Field-South. Source identifications are carried out using deep optical-to-radio multiwavelength catalogs, and are then combined to create lists of primary and secondary counterparts for the X-ray sources. We identified reliable counterparts for 446 (96.5%) of the X-ray sources, with an expected false-match probability of ~6.2%. A...
Source: http://arxiv.org/abs/1002.3154v2
50
50
Dec 21, 2009
12/09
Dec 21, 2009
by
F. E. Bauer; Lin Yan; A. Sajina; D. M. Alexander
texts
eye 50
favorite 0
comment 0
We report X-ray constraints for 20 of 52 high-z ULIRGs identified in the Spitzer xFLS to constrain their obscuration. Notably, decomposition of Spitzer-IRS spectra for the 52 objects already indicates that most are weak-PAH ULIRGs dominated by hot-dust continua, characteristic of AGN. Given their redshifts, they have AGN bolometric luminosities of ~1e45-1e47 erg/s comparable to powerful QSOs. This, coupled with their high IR-to-optical ratios and often significant silicate absorption, strongly...
Source: http://arxiv.org/abs/0912.4267v1
58
58
Jun 23, 2009
06/09
Jun 23, 2009
by
J. E. Geach; D. M. Alexander; B. D. Lehmer; Ian Smail; Y. Matsuda; S. C. Chapman; C. A. Scharf; R. J. Ivison; M. Volonteri; T. Yamada; A. W. Blain; R. G. Bower; F. E. Bauer; A. Basu-Zych
texts
eye 58
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We present the results of a 400ks Chandra survey of 29 extended Ly-alpha emitting nebulae (Ly-alpha Blobs, LABs) in the z=3.09 proto-cluster in the SSA22 field. We detect luminous X-ray counterparts in five LABs, implying a large fraction of active galactic nuclei (AGN) in LABs, f_AGN = 17% down to L_2-32keV ~ 10^44 erg/s. All of the AGN appear to be heavily obscured, with spectral indices implying obscuring column densities of N_H > 10^23 cm^-2. The AGN fraction should be considered a lower...
Source: http://arxiv.org/abs/0904.0452v3
