41
41
Sep 23, 2013
09/13
by
A. Alonso-Herrero; P. G. Perez-Gonzalez; D. M. Alexander; G. H. Rieke; D. Rigopoulou; E. Le Floc'h; P. Barmby; C. Papovich; J. R. Rigby; F. E. Bauer; W. N. Brandt; E. Egami; S. P. Willner; H. Dole; J. -S. Huang
texts
eye 41
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We investigate the nature of a sample of 92 Spitzer/MIPS 24 micron selected galaxies in the CDFS, showing power law-like emission in the Spitzer/IRAC 3.6-8 micron bands. The main goal is to determine whether the galaxies not detected in X-rays (47% of the sample) are part of the hypothetical population of obscured AGN not detected even in deep X-ray surveys. The majority of the IR power-law galaxies are ULIRGs at z>1, and those with LIRG-like IR luminosities are usually detected in X-rays....
Source: http://arxiv.org/abs/astro-ph/0511507v1
4
4.0
Jun 30, 2018
06/18
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 4
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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
17
17
Jun 28, 2018
06/18
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 17
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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
34
34
Sep 23, 2013
09/13
by
A. Comastri; P. Ranalli; K. Iwasawa; C. Vignali; R. Gilli; I. Georgantopoulos; X. Barcons; W. N. Brandt; H. Brunner; M. Brusa; N. Cappelluti; F. J. Carrera; F. Civano; F. Fiore; G. Hasinger; V. Mainieri; A. Merloni; F. Nicastro; M. Paolillo; S. Puccetti; P. Rosati; J. D. Silverman; P. Tozzi; G. Zamorani; I. Balestra; F. E. Bauer; B. Luo; Y. Q. Xue
texts
eye 34
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We present the first results of the spectroscopy of distant, obscured AGN as obtained with the ultra-deep (~3.3 Ms) XMM-Newton survey in the Chandra Deep Field South (CDFS). One of the primary goals of the project is to characterize the X-ray spectral properties of obscured and heavily obscured Compton-thick AGN over the range of redhifts and luminosities that are relevant in terms of their contribution to the X-ray background. The ultra-deep exposure, coupled with the XMM detector's spectral...
Source: http://arxiv.org/abs/1012.4011v2
58
58
Sep 20, 2013
09/13
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 58
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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
11
11
Jun 27, 2018
06/18
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 11
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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
46
46
Sep 22, 2013
09/13
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 46
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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
5
5.0
Jun 30, 2018
06/18
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 5
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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
38
38
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
texts
eye 38
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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
50
50
Sep 17, 2013
09/13
by
A. E. Hornschemeier; F. E. Bauer; D. M. Alexander; W. N. Brandt; W. L. W. Sargent; M. W. Bautz; C. Conselice; G. P. Garmire; D. P. Schneider; G. Wilson
texts
eye 50
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We have analyzed optically bright, X-ray faint [OBXF; i.e., log(fX/fR) < -2] sources identified in an 178.9 square arcminute area within the Chandra Deep Field-North (CDF-N) 2 Ms survey. We find 43 OBXF sources in this area, comprising ~15% of the X-ray sources above a 0.5--2 keV flux of 2.3e-17 erg cm^-2 s^-1. We present spectroscopic identifications for 42 of the OBXF sources and optical spectra for 25, including 5 previously unpublished redshifts. Deep optical imaging data (either HST or...
Source: http://arxiv.org/abs/astro-ph/0305086v1
59
59
Sep 18, 2013
09/13
by
A. E. Hornschemeier; W. N. Brandt; D. M. Alexander; F. E. Bauer; G. P. Garmire; D. P. Schneider; M. W. Bautz; G. Chartas
texts
eye 59
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We present a statistical X-ray study of spiral galaxies in the Hubble Deep Field-North and its Flanking Fields using the Chandra Deep Field North 1 Ms dataset. We find that approximately L_star galaxies with 0.4 < z < 1.5 have ratios of X-ray to B-band luminosity similar to those in the local Universe, although the data indicate a likely increase in this ratio by a factor of approximately 2-3. We have also determined that typical spiral galaxies at 0.4 < z < 1.5 should be detected...
Source: http://arxiv.org/abs/astro-ph/0110094v2
9
9.0
Jun 26, 2018
06/18
by
A. Finoguenov; M. Tanaka; M. Cooper; V. Allevato; N. Cappelluti; A. Choi; C. Heymans; F. E. Bauer; F. Ziparo; P. Ranalli; J. Silverman; W. N. Brandt; Y. Q. Xue; J. Mulchaey; L. Howes; C. Schmid; D. Wilman; A. Comastri; G. Hasinger; V. Mainieri; B. Luo; P. Tozzi; P. Rosati; P. Capak; P. Popesso
texts
eye 9
favorite 0
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Ultra-deep observations of ECDF-S with Chandra and XMM-Newton enable a search for extended X-ray emission down to an unprecedented flux of $2\times10^{-16}$ ergs s$^{-1}$ cm$^{-2}$. We present the search for the extended emission on spatial scales of 32$^{\prime\prime}$ in both Chandra and XMM data, covering 0.3 square degrees and model the extended emission on scales of arcminutes. We present a catalog of 46 spectroscopically identified groups, reaching a redshift of 1.6. We show that the...
Topics: Cosmology and Nongalactic Astrophysics, Astrophysics, Astrophysics of Galaxies, High Energy...
Source: http://arxiv.org/abs/1501.03506
40
40
Sep 18, 2013
09/13
by
A. J. Barger; L. L. Cowie; P. Capak; D. M. Alexander; F. E. Bauer; E. Fernandez; W. N. Brandt; G. P. Garmire; A. E. Hornschemeier
texts
eye 40
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We present an optical and NIR catalog for the X-ray sources in the 2 Ms Chandra observation of the Hubble Deep Field-North region. We have high-quality multicolor images of all 503 X-ray point sources and reliable spectroscopic redshifts for 284. We spectroscopically identify six z>1 type II quasars. Our spectroscopic completeness for the R
Source: http://arxiv.org/abs/astro-ph/0306212v1
42
42
Sep 20, 2013
09/13
by
A. J. Barger; L. L. Cowie; P. Capak; D. M. Alexander; F. E. Bauer; W. N. Brandt; G. P. Garmire; A. E. Hornschemeier
texts
eye 42
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Deep Chandra X-ray exposures provide an efficient route for locating optically faint active galactic nuclei (AGN) at high redshifts. We use deep multicolor optical data to search for z>5 AGN in the 2 Ms X-ray exposure of the Chandra Deep Field-North. Of the 423 X-ray sources bright enough (z' 6. The z>5 object is spectroscopically confirmed at z=5.19. Only 31 of the 77 sources with z'>25.2 are undetected in the B or V bands at the 2-sigma level and could lie at z>5. There are too...
Source: http://arxiv.org/abs/astro-ph/0301232v1
4
4.0
Jun 30, 2018
06/18
by
A. Marinucci; G. Matt; S. Bianchi; T. N. Lu; P. Arevalo; M. Baloković; D. Ballantyne; F. E. Bauer; S. E. Boggs; F. E. Christensen; W. W. Craig; P. Gandhi; C. J. Hailey; F. Harrison; S. Puccetti; E. Rivers; D. J. Walton; D. Stern; W. Zhang
texts
eye 4
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We present NuSTAR observations of the bright Seyfert 2 galaxy NGC 2110 obtained in 2012, when the source was at the highest flux level ever observed, and in 2013, when the source was at a more typical flux level. We include archival observations from other X-ray satellites, namely XMM-Newton, Suzaku, BeppoSAX, Chandra and Swift. Simultaneous NuSTAR and Swift broad band spectra (in the 3-80 keV range) indicate a cutoff energy $E_{\rm c}>210$ keV, with no detectable contribution from Compton...
Topics: High Energy Astrophysical Phenomena, Astrophysics
Source: http://arxiv.org/abs/1411.5151
6
6.0
Jun 28, 2018
06/18
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 6
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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
Jun 29, 2018
06/18
by
A. Masini; A. Comastri; M. Baloković; I. Zaw; S. Puccetti; D. R. Ballantyne; F. E. Bauer; S. E. Boggs; W. N. Brandt; M. Brightman; F. E. Christensen; W. W. Craig; P. Gandhi; C. J. Hailey; F. A. Harrison; M. J. Koss; G. Madejski; C. Ricci; E. Rivers; D. Stern; W. W. Zhang
texts
eye 3
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Aims. Study the connection between the masing disk and obscuring torus in Seyfert 2 galaxies. Methods. We present a uniform X-ray spectral analysis of the high energy properties of 14 nearby megamaser Active Galactic Nuclei observed by NuSTAR. We use a simple analytical model to localize the maser disk and understand its connection with the torus by combining NuSTAR spectral parameters with available physical quantities from VLBI mapping. Results. Most of the sources analyzed are heavily...
Topics: Astrophysics, High Energy Astrophysical Phenomena, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1602.03185
3
3.0
Jun 29, 2018
06/18
by
A. Masini; A. Comastri; S. Puccetti; M. Baloković; P. Gandhi; M. Guainazzi; F. E. Bauer; S. E. Boggs; P. G. Boorman; M. Brightman; F. E. Christensen; W. W. Craig; D. Farrah; C. J. Hailey; F. A. Harrison; M. J. Koss; S. M. LaMassa; C. Ricci; D. Stern; D. J. Walton; W. W. Zhang
texts
eye 3
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Aims. We study the long-term variability of the well-known Seyfert 2 galaxy Mrk 1210 (a.k.a. UGC 4203, or the Phoenix galaxy). Methods. The source was observed by many X-ray facilities in the last 20 years. Here we present a NuSTAR observation and put the results in context of previously published observations. Results. NuSTAR observed Mrk 1210 in 2012 for 15.4 ks. The source showed Compton-thin obscuration similar to that observed by Chandra, Suzaku, BeppoSAX and XMM-Newton over the past two...
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1609.00374
66
66
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
texts
eye 66
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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
7
7.0
Jun 30, 2018
06/18
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
texts
eye 7
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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
2
2.0
Jun 29, 2018
06/18
by
B. D. Lehmer; A. R. Basu-Zych; S. Mineo; W. N. Brandt; R. T. Eufrasio; T. Fragos; A. E. Hornschemeier; B. Luo; Y. Q. Xue; F. E. Bauer; M. Gilfanov; P. Ranalli; D. P. Schneider; O. Shemmer; P. Tozzi; J. R. Trump; C. Vignali; J. -X. Wang; M. Yukita; A. Zezas
texts
eye 2
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We present measurements of the evolution of normal-galaxy X-ray emission from $z \approx$ 0-7 using local galaxies and galaxy samples in the 6 Ms Chandra Deep Field-South (CDF-S) survey. The majority of the CDF-S galaxies are observed at rest-frame energies above 2 keV, where the emission is expected to be dominated by X-ray binary (XRB) populations; however, hot gas is expected to provide small contributions to the observed- frame < 1 keV emission at $z < 1$. We show that a single...
Topics: Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1604.06461
39
39
Sep 19, 2013
09/13
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 39
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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
46
46
Sep 18, 2013
09/13
by
B. D. Lehmer; D. M. Alexander; J. E. Geach; Ian Smail; A. Basu-Zych; F. E. Bauer; S. C. Chapman; Y. Matsuda; C. A. Scharf; M. Volonteri; T. Yamada
texts
eye 46
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We present results from a new ultra-deep 400 ks Chandra observation of the SSA22 protocluster at z = 3.09. We have studied the X-ray properties of 234 z ~ 3 Lyman break galaxies (LBGs; protocluster and field) and 158 z = 3.09 Ly-alpha emitters (LAEs) in SSA22 to measure the influence of the high-density protocluster environment on the accretion activity of supermassive black holes (SMBHs) in these UV-selected star forming populations. We detect individually X-ray emission from active galactic...
Source: http://arxiv.org/abs/0809.5058v1
50
50
Sep 21, 2013
09/13
by
B. D. Lehmer; W. N. Brandt; A. E. Hornschemeier; D. M. Alexander; F. E. Bauer; A. M. Koekemoer; D. P. Schneider; A. T. Steffen
texts
eye 50
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We analyze a population of intermediate-redshift (z ~ 0.05-0.3), off-nuclear X-ray sources located within optically-bright galaxies in the Great Observatories Origins Deep Survey (GOODS) and Galaxy Evolution from Morphology and SEDs (GEMS) fields. A total of 24 off-nuclear source candidates are classified using deep Chandra exposures from the Chandra Deep Field-North, Chandra Deep Field-South, and Extended Chandra Deep Field-South; 15 of these are newly identified. These sources have average...
Source: http://arxiv.org/abs/astro-ph/0602001v1
47
47
Sep 18, 2013
09/13
by
B. D. Lehmer; W. N. Brandt; D. M. Alexander; E. F. Bell; A. E. Hornschemeier; D. H. McIntosh; F. E. Bauer; R. Gilli; V. Mainieri; D. P. Schneider; J. D. Silverman; A. T. Steffen; P. Tozzi; C. Wolf
texts
eye 47
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We report on the X-ray evolution over the last ~9 Gyr of cosmic history (i.e., since z = 1.4) of late-type galaxy populations in the Chandra Deep Field-North and Extended Chandra Deep Field-South (CDF-N and E-CDF-S, respectively; jointly CDFs) survey fields. Our late-type galaxy sample consists of 2568 galaxies, which were identified using rest-frame optical colors and HST morphologies. We utilized X-ray stacking analyses to investigate the X-ray emission from these galaxies, emphasizing the...
Source: http://arxiv.org/abs/0803.3620v2
47
47
Sep 20, 2013
09/13
by
B. D. Lehmer; W. N. Brandt; D. M. Alexander; E. F. Bell; D. H. McIntosh; F. E. Bauer; G. Hasinger; V. Mainieri; T. Miyaji; D. P. Schneider; A. T. Steffen
texts
eye 47
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We investigate the evolution over the last 6.3 Gyr of cosmic time (i.e., since z ~ 0.7) of the average X-ray properties of early-type galaxies within the Extended Chandra Deep Field-South (E-CDF-S). Our early-type galaxy sample includes 539 objects with red-sequence colors and Sersic indices larger than n = 2.5, which were selected jointly from the COMBO-17 (Classifying Objects by Medium-Band Observations in 17 Filters) and GEMS (Galaxy Evolution from Morphologies and SEDs) surveys. We utilize...
Source: http://arxiv.org/abs/astro-ph/0612003v1
60
60
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
texts
eye 60
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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
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46
Sep 20, 2013
09/13
by
B. D. Lehmer; W. N. Brandt; D. M. Alexander; F. E. Bauer; D. P. Schneider; P. Tozzi; J. Bergeron; G. P. Garmire; R. Giacconi; R. Gilli; G. Hasinger; A. E. Hornschemeier; A. M. Koekemoer; V. Mainieri; T. Miyaji; M. Nonino; P. Rosati; J. D. Silverman; G. Szokoly; C. Vignali
texts
eye 46
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We present Chandra point-source catalogs for the Extended Chandra Deep Field-South (E-CDF-S) survey. The E-CDF-S consists of four contiguous 250 ks Chandra observations covering an approximately square region of total solid angle ~0.3 deg^2, which flank the existing ~1 Ms Chandra Deep Field-South (CDF-S). The survey reaches sensitivity limits of 1.1 X 10^-16 erg/cm^2/s and 6.7 X 10^-16 erg/cm^2/s for the 0.5-2.0 keV and 2-8 keV bands, respectively. We detect 762 distinct X-ray point sources...
Source: http://arxiv.org/abs/astro-ph/0506607v2
47
47
Sep 21, 2013
09/13
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 47
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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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74
Sep 17, 2013
09/13
by
B. Luo; W. N. Brandt; A. T. Steffen; F. E. Bauer
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eye 74
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Luminous X-ray outbursts with variability amplitudes as high as ~1000 have been detected from a small number of galactic nuclei. These events are likely associated with transient fueling of nuclear supermassive black holes. In this paper, we constrain X-ray outbursts with harder spectra, higher redshifts, and lower luminosities than have been studied previously. We performed a systematic survey of 24668 optical galaxies in the Chandra Deep Fields to search for such X-ray outbursts; the median...
Source: http://arxiv.org/abs/0711.2517v1
7
7.0
Jun 30, 2018
06/18
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
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eye 7
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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
45
45
Sep 21, 2013
09/13
by
B. Luo; W. N. Brandt; J. D. Silverman; I. V. Strateva; F. E. Bauer; P. Capak; J. Kartaltepe; B. D. Lehmer; V. Mainieri; M. Salvato; G. Szokoly; D. P. Schneider; C. Vignali
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eye 45
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We report the discovery of the most-distant double-peaked emitter, CXOECDFS J033115.0-275518, at z=1.369. A Keck/DEIMOS spectrum shows a clearly double-peaked broad Mg II $\lambda2799$ emission line, with FWHM 11000 km/s for the line complex. The line profile can be well fit by an elliptical relativistic Keplerian disk model. This is one of a handful of double-peaked emitters known to be a luminous quasar, with excellent multiwavelength coverage and a high-quality X-ray spectrum. CXOECDFS...
Source: http://arxiv.org/abs/0901.2929v1
4
4.0
Jun 29, 2018
06/18
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
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eye 4
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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
136
136
Jul 20, 2013
07/13
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
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eye 136
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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
47
47
Sep 20, 2013
09/13
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
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eye 47
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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
4
4.0
Jun 29, 2018
06/18
by
C. C. Thöne; A. de Ugarte Postigo; G. Leloudas; C. Gall; Z. Cano; K. Maeda; S. Schulze; S. Campana; K. Wiersema; J. Groh; J. de la Rosa; F. E. Bauer; D. Malesani; J. Maund; N. Morrell; Y. Beletsky
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eye 4
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Very massive stars in the final phases of their lives often show unpredictable outbursts that can mimic supernovae, so-called, "SN impostors", but the distinction is not always straigthforward. Here we present observations of a luminous blue variable (LBV) in NGC 2770 in outburst over more than 20 years that experienced a possible terminal explosion as type IIn SN in 2015, named SN 2015bh. This possible SN or "main event" was preceded by a precursor peaking $\sim$ 40 days...
Topics: Astrophysics, High Energy Astrophysical Phenomena, Solar and Stellar Astrophysics
Source: http://arxiv.org/abs/1606.09025
2
2.0
Jun 30, 2018
06/18
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
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eye 2
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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
56
56
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
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eye 56
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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
2
2.0
Jun 28, 2018
06/18
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
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eye 2
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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
46
46
Sep 22, 2013
09/13
by
C. Meunier; F. E. Bauer; V. V. Dwarkadas; B. Koribalski; B. Emonts; R. W. Hunstead; D. Campbell-Wilson; C. Stockdale; S. J. Tingay
texts
eye 46
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We present archival radio observations of SN1996cr from ATCA and MOST, and model its radio lightcurves using X-ray constrained hydrodynamical simulations of the interaction between the SN ejecta and the CSM. The early radio data show signs of free-free absorption (FFA), which decreases gradually and is minimal above 1.4 GHz after day ~3000. FFA optical depth constraints provide estimates of the CSM free electron density, which allows insight into the ionisation of SN1996cr's CSM and offers a...
Source: http://arxiv.org/abs/1302.5432v1
5
5.0
Jun 29, 2018
06/18
by
C. Ricci; F. E. Bauer; E. Treister; C. Romero-Canizales; P. Arevalo; K. Iwasawa; G. C. Privon; D. B. Sanders; K. Schawinski; D. Stern; M. Imanishi
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eye 5
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We report the detection of a heavily obscured Active Galactic Nucleus (AGN) in the luminous infrared galaxy (LIRG) NGC 6286, identified in a 17.5 ks NuSTAR observation. The source is in an early merging stage, and was targeted as part of our ongoing NuSTAR campaign observing local luminous and ultra-luminous infrared galaxies in different merger stages. NGC 6286 is clearly detected above 10 keV and, by including the quasi-simultaneous Swift/XRT and archival XMM-Newton and Chandra data, we find...
Topics: Astrophysics, High Energy Astrophysical Phenomena, Cosmology and Nongalactic Astrophysics,...
Source: http://arxiv.org/abs/1601.05800
8
8.0
Jun 29, 2018
06/18
by
C. Ricci; F. E. Bauer; P. Arevalo; S. Boggs; W. N. Brandt; F. E. Christensen; W. W. Craig; P. Gandhi; C. J. Hailey; F. A. Harrison; M. Koss; C. B. Markwardt; D. Stern; E. Treister; W. W. Zhang
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eye 8
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We present the results of five NuSTAR observations of the type 2 active galactic nucleus (AGN) in IC 751, three of which were performed simultaneously with XMM-Newton or Swift/XRT. We find that the nuclear X-ray source underwent a clear transition from a Compton-thick ($N_{\rm\,H}\simeq 2\times 10^{24}\rm\,cm^{-2}$) to a Compton-thin ($N_{\rm\,H}\simeq 4\times 10^{23}\rm\,cm^{-2}$) state on timescales of $\lesssim 3$ months, which makes IC 751 the first changing-look AGN discovered by NuSTAR....
Topics: Astrophysics, High Energy Astrophysical Phenomena, Cosmology and Nongalactic Astrophysics,...
Source: http://arxiv.org/abs/1602.00702
7
7.0
Jun 29, 2018
06/18
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 7
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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
2
2.0
Jun 29, 2018
06/18
by
C. Ricci; Y. Ueda; M. J. Koss; B. Trakhtenbrot; F. E. Bauer; P. Gandhi
texts
eye 2
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Heavily obscured accretion is believed to represent an important stage in the growth of supermassive black holes, and to play an important role in shaping the observed spectrum of the Cosmic X-ray Background (CXB). Hard X-ray (E$>$10 keV) selected samples are less affected by absorption than samples selected at lower energies, and are therefore one of the best ways to detect and identify Compton-thick (CT, $\log N_{\rm\,H}\geq 24$) Active Galactic Nuclei (AGN). In this letter we present the...
Topics: Astrophysics, High Energy Astrophysical Phenomena, Cosmology and Nongalactic Astrophysics,...
Source: http://arxiv.org/abs/1603.04852
4
4.0
Jun 30, 2018
06/18
by
C. Ricci.; F. E. Bauer; E. Treister; K. Schawinski; G. C. Privon; L. Blecha; P. Arevalo; L. Armus; F. Harrison; L. C. Ho; K. Iwasawa; D. B. Sanders; D. Stern
texts
eye 4
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Mergers of galaxies are thought to cause significant gas inflows to the inner parsecs, which can activate rapid accretion onto supermassive black holes (SMBHs), giving rise to Active Galactic Nuclei (AGN). During a significant fraction of this process, SMBHs are predicted to be enshrouded by gas and dust. Studying 52 galactic nuclei in infrared-selected local Luminous and Ultra-luminous infrared galaxies in different merger stages in the hard X-ray band, where radiation is less affected by...
Topics: Cosmology and Nongalactic Astrophysics, Astrophysics of Galaxies, Astrophysics, High Energy...
Source: http://arxiv.org/abs/1701.04825
5
5.0
Jun 30, 2018
06/18
by
C. Romero-Cañizales; R. Herrero-Illana; M. A. Pérez-Torres; A. Alberdi; E. Kankare; F. E. Bauer; S. D. Ryder; S. Mattila; J. E. Conway; R. J. Beswick; T. W. B. Muxlow
texts
eye 5
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We report radio observations of two stripped-envelope supernovae (SNe), 2010O and 2010P, which exploded within a few days of each other in the luminous infrared galaxy Arp 299. Whilst SN 2010O remains undetected at radio frequencies, SN 2010P was detected (with an astrometric accuracy better than 1 milli arcsec in position) in its optically thin phase in epochs ranging from ~1 to ~3yr after its explosion date, indicating a very slow radio evolution and a strong interaction of the SN ejecta with...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1403.1036
9
9.0
Jun 27, 2018
06/18
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 9
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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
62
62
Sep 23, 2013
09/13
by
C. Saez; G. Chartas; W. N. Brandt; B. D. Lehmer; F. E. Bauer; X. Dai; G. P. Garmire
texts
eye 62
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We present results from a statistical analysis of 173 bright radio-quiet AGNs selected from the Chandra Deep Field-North and Chandra Deep Field-South surveys (hereafter, CDFs) in the redshift range of 0.1 < z < 4. We find that the X-ray power-law photon index (Gamma) of radio-quiet AGNs is correlated with their 2-10 keV rest-frame X-ray luminosity (L_X) at the > 99.5 percent confidence level in two redshift bins, 0.3 < z < 0.96, and 1.5 < z < 3.3 and is slightly less...
Source: http://arxiv.org/abs/0801.3599v1
67
67
Sep 19, 2013
09/13
by
C. Vignali; D. M. Alexander; F. E. Bauer; W. N. Brandt; A. E. Hornschemeier; G. P. Garmire; D. P. Schneider
texts
eye 67
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Understanding the nature of Extremely Red Objects [EROs; (I-K)>=4] is one of the most challenging issues in observational cosmology. Here we report on the X-ray constraints provided by the 2 Ms Chandra Deep Field-North Survey (CDF-N). X-ray emission has been detected from 11 out of 36 EROs (approx 30%). Five of these have hard X-ray emission and appear to be obscured AGNs, while non-AGN emission (star formation or normal elliptical galaxy emission) is likely to be the dominant source of...
Source: http://arxiv.org/abs/astro-ph/0209415v1
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44
Sep 18, 2013
09/13
by
C. Vignali; F. E. Bauer; D. M. Alexander; W. N. Brandt; A. E. Hornschemeier; D. P. Schneider; G. P. Garmire
texts
eye 44
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We present X-ray spectral analyses of the three z>4 Active Galactic Nuclei (AGNs) thus far spectroscopically identified in the Chandra Deep Field-North Survey, at redshifts of 5.186, 4.424, and 4.137. These analyses are made possible by the extremely deep exposure (2 Ms) and the low Chandra background. The rest-frame 2.5-40 keV spectra are the first for optically faint (two of the three sources have I>24) z>4 AGNs. The z=5.186 quasar is well fitted by a power-law model with photon...
Source: http://arxiv.org/abs/astro-ph/0210552v1
