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
texts
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
2
2.0
Jun 29, 2018
06/18
by
K. I. I. Koljonen; D. M. Russell; J. M. Corral-Santana; M. Armas Padilla; T. Muñoz-Darias; F. Lewis; M. Coriat; F. E. Bauer
texts
eye 2
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We study in detail the evolution of the 2015 outburst of GS 1354-64 (BW Cir) at optical, UV and X-ray wavelengths using Faulkes Telescope South/LCOGT, SMARTS and Swift. The outburst was found to stay in the hard X-ray state, albeit being anomalously luminous with a peak luminosity of L$_{X} >$ 0.15 L$_{Edd}$, which could be the most luminous hard state observed in a black hole X-ray binary. We found that the optical/UV emission is tightly correlated with the X-ray emission, consistent with...
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1602.06414
51
51
Sep 18, 2013
09/13
by
M. P. Muno; F. E. Bauer; F. K. Baganoff; R. M. Bandyopadhyay; G. C. Bower; W. N. Brandt; P. S. Broos; A. Cotera; S. S. Eikenberry; G. P. Garmire; S. D. Hyman; N. E. Kassim; C. C. Lang; T. J. W. Lazio; C. Law; J. C. Mauerhan; M. R. Morris; T. Nagata; S. Nishiyama; S. Park; S. V. Ramirez; S. R. Stolovy; R. Wijnands; Q. D. Wang; Z. Wang; F. Yusef-Zadeh
texts
eye 51
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We present a catalog of 9017 X-ray sources identified in Chandra observations of a 2 by 0.8 degree field around the Galactic center. We increase the number of known X-ray sources in the region by a factor of 2.5. The catalog incorporates all of the ACIS-I observations as of 2007 August, which total 2.25 Msec of exposure. At the distance to the Galactic center (8 kpc), we are sensitive to sources with luminosities >4e32 erg/s (0.5-8.0 keV; 90% confidence) over an area of one square degree,...
Source: http://arxiv.org/abs/0809.1105v1
47
47
Sep 20, 2013
09/13
by
M. P. Muno; F. E. Bauer; R. M. Bandyopadhyay; Q. D. Wang
texts
eye 47
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We present the catalog of X-ray sources detected in a shallow Chandra survey of the inner 2 by 0.8 degrees of the Galaxy, and in two deeper observations of the Radio Arches and Sgr B2. The catalog contains 1352 objects that are highly-absorbed (N_H > 4e22 cm^-2 and are therefore likely to lie near the Galactic center (D~8 kpc), and 549 less-absorbed sources that lie within
Source: http://arxiv.org/abs/astro-ph/0601627v1
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
41
41
Sep 21, 2013
09/13
by
F. E. Bauer; W. N. Brandt; R. M. Sambruna; G. Chartas; G. P. Garmire; S. Kaspi; H. Netzer
texts
eye 41
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We have used the Chandra X-ray Observatory to resolve spatially and spectrally the X-ray emission from the Circinus Galaxy. We report here on the nature of the X-ray emission from the off-nuclear point sources associated with the disk of Circinus. We find that many of the serendipitous X-ray sources are concentrated along the optical disk of the galaxy, but few have optical counterparts within 1" of their X-ray positions down to V=23-25. At 3.8 Mpc, their intrinsic 0.5-10 keV luminosities...
Source: http://arxiv.org/abs/astro-ph/0104035v1
58
58
Sep 23, 2013
09/13
by
D. M. Alexander; G. Chartas; F. E. Bauer; W. N. Brandt; C. Simpson; C. Vignali
texts
eye 58
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We present a ~20 ks Chandra ACIS-S observation of the strongly lensed z=2.285 ultra-luminous infrared galaxy FSC10214+4724. Although this observation achieves the equivalent sensitivity of an up-to ~4 Ms Chandra exposure (when corrected for gravitational lensing), the rest-frame 1.6-26.3 keV emission from FSC10214+4724 is weak (L_X~2E42 erg/s for a lensing boost of ~100); a significant fraction of this X-ray emission appears to be due to vigorous star-formation activity. If FSC10214+4724 hosts...
Source: http://arxiv.org/abs/astro-ph/0411289v1
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
favorite 0
comment 0
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
Jun 29, 2018
06/18
by
Michael J. Koss; R. Assef; M. Balokovic; D. Stern; P. Gandhi; I. Lamperti; D. M. Alexander; D. R. Ballantyne; F. E. Bauer; S. Berney; W. N. Brandt; A. Comastri; N. Gehrels; F. A. Harrison; G. Lansbury; C. Markwardt; C. Ricci; E. Rivers; K. Schawinski; E. Treister; C. Megan Urry
texts
eye 3
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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
Jun 30, 2018
06/18
by
F. E. Bauer; E. Treister; K. Schawinski; S. Schulze; B. Luo; D. M. Alexander; W. N. Brandt; A. Comastri; F. Forster; R. Gilli; D. A. Kann; K. Maeda; K. Nomoto; M. Paolillo; P. Ranalli; D. P. Schneider; O. Shemmer; M. Tanaka; A. Tolstov; N. Tominaga; P. Tozzi; C. Vignali; J. Wang; Y. Xue; G. Yang
texts
eye 4
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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
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
42
42
Sep 19, 2013
09/13
by
N. A. Grogin; C. J. Conselice; E. Chatzichristou; D. M. Alexander; F. E. Bauer; A. E. Hornschemeier; S. Jogee; A. M. Koekemoer; V. G. Laidler; M. Livio; R. A. Lucas; M. Paolillo; S. Ravindranath; E. J. Schreier; B. D. Simmons; C. M. Urry
texts
eye 42
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We investigate morphological structure parameters and local environments of distant moderate-luminosity active galactic nucleus (AGN) host galaxies in the overlap between the HST/ACS observations of the Great Observatories Origins Deep Survey (GOODS) and the two Chandra Deep Fields. We compute near-neighbor counts and BViz asymmetry (A) and concentration (C) indices for ~35,500 GOODS/ACS galaxies complete to z_850 ~ 26.6, including the resolved hosts of 322 X-ray-selected AGNs. Distributions of...
Source: http://arxiv.org/abs/astro-ph/0507091v1
7
7.0
Jun 29, 2018
06/18
by
M. Aravena; R. Decarli; F. Walter; R. Bouwens; P. A. Oesch; C. L. Carilli; F. E. Bauer; E. Da Cunha; E. Daddi; J. Gónzalez-López; R. J. Ivison; D. A. Riechers; Ian Smail; A. M. Swinbank; A. Weiss; T. Anguita; R. Bacon; E. Bell; F. Bertoldi; P. Cortes; P. Cox; J. Hodge; E. Ibar; H. Inami; L. Infante; A. Karim; B. Magnelli; K. Ota; G. Popping; P. van der Werf; J. Wagg; Y. Fudamoto
texts
eye 7
favorite 0
comment 0
We present a search for [CII] line and dust continuum emission from optical dropout galaxies at $z>6$ using ASPECS, our ALMA Spectroscopic Survey in the Hubble Ultra-Deep Field (UDF). Our observations, which cover the frequency range $212-272$ GHz, encompass approximately the range $6$4.5 $\sigma$, two of which correspond to blind detections with no optical counterparts. At this significance level, our statistical analysis shows that about 60\% of our candidates are expected to be spurious....
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1607.06772
4
4.0
Jun 29, 2018
06/18
by
M. Aravena; R. Decarli; F. Walter; E. Da Cunha; F. E. Bauer; C. L. Carilli; E. Daddi; D. Elbaz; R. J. Ivison; D. A. Riechers; I. Smail; A. M. Swinbank; A. Weiss; T. Anguita; R. J. Assef; E. Bell; F. Bertoldi; R. Bacon; R. Bouwens; P. Cortes; P. Cox; J. Gónzalez-López; J. Hodge; E. Ibar; H. Inami; L. Infante; A. Karim; O. Le Fèvre; B. Magnelli; K. Ota; G. Popping; K. Sheth; P. van der Werf; J. Wagg
texts
eye 4
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We present an analysis of a deep (1$\sigma$=13 $\mu$Jy) cosmological 1.2-mm continuum map based on ASPECS, the ALMA Spectroscopic Survey in the Hubble Ultra Deep Field. In the 1 arcmin$^2$ covered by ASPECS we detect nine sources at $>3.5\sigma$ significance at 1.2-mm. Our ALMA--selected sample has a median redshift of $z=1.6\pm0.4$, with only one galaxy detected at z$>$2 within the survey area. This value is significantly lower than that found in millimeter samples selected at a higher...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1607.06769
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
42
42
Sep 18, 2013
09/13
by
R. M. Bandyopadhyay; J. C. A. Miller-Jones; K. M. Blundell; F. E. Bauer; Ph. Podsiadlowski; A. J. Gosling; Q. D. Wang; E. Pfahl; S. Rappaport
texts
eye 42
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We present near-IR imaging of a sample of the faint, hard X-ray sources discovered in the 2001 Chandra ACIS-I survey towards the Galactic Centre (GC) (Wang et al. 2002). These ~800 discrete sources represent an important and previously undetected population within the Galaxy. From our VLT observations of 77 X-ray sources, we identify candidate K-band counterparts to 75% of the Chandra sources in our sample. The near-IR magnitudes and colours of the majority of candidate counterparts are...
Source: http://arxiv.org/abs/astro-ph/0509346v1
7
7.0
Jun 27, 2018
06/18
by
Michael J. Koss; C. Romero-Canizales; L. Baronchelli; S. H. Teng; M. Balokovic; S. Puccetti; F. E. Bauer; P. Arevalo; R. Assef; D. R. Ballantyne; W. N. Brandt; M. Brightman; A. Comastri; P. Gandhi; F. A. Harrison; B. Luo; K. Schawinski; D. Stern; E. Treister
texts
eye 7
favorite 0
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We present new NuSTAR and Chandra observations of NGC 3393, a galaxy reported to host the smallest separation dual AGN resolved in the X-rays. While past results suggested a 150 pc separation dual AGN, three times deeper Chandra imaging, combined with adaptive optics and radio imaging suggest a single, heavily obscured, radio-bright AGN. Using VLA and VLBA data, we find an AGN with a two-sided jet rather than a dual AGN and that the hard X-ray, UV, optical, NIR, and radio emission are all from...
Topics: High Energy Astrophysical Phenomena, Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1505.03524
48
48
Sep 21, 2013
09/13
by
M. A. Worsley; A. C. Fabian; F. E. Bauer; D. M. Alexander; W. N. Brandt; B. D. Lehmer
texts
eye 48
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comment 0
The emission from individual X-ray sources in the Chandra Deep Fields and XMM-Newton Lockman Hole shows that almost half of the hard X-ray background above 6 keV is unresolved and implies the existence of a missing population of heavily obscured active galactic nuclei (AGN). We have stacked the 0.5-8 keV X-ray emission from optical sources in the Great Observatories Origins Deep Survey (GOODS; which covers the Chandra Deep Fields) to determine whether these galaxies, which are individually...
Source: http://arxiv.org/abs/astro-ph/0602605v1
103
103
Sep 18, 2013
09/13
by
T. X. Thuan; F. E. Bauer; P. Papaderos; Y. I. Izotov
texts
eye 103
favorite 0
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We present an X-ray study of the three most metal-deficient blue compact dwarf (BCD) galaxies known in the local Universe, based on deep Chandra observations of SBS 0335-052 (0.025 solar abundance), SBS 0335-052W (0.02 solar abundance) and I Zw 18 (0.02 solar abundance). All three are detected, with more than 90% of their X-ray emission arising from point-like sources. The 0.5-10.0 keV luminosities of these point sources are in the range (1.3-8.5)x1e39 erg/s. We interpret them to be single or a...
Source: http://arxiv.org/abs/astro-ph/0401349v1
48
48
Sep 22, 2013
09/13
by
F. E. Bauer; W. N. Brandt
texts
eye 48
favorite 0
comment 0
We present a Chandra and HST study of IC 10 X-1, the most luminous X-ray binary in the closest starburst galaxy to the Milky Way. Our new hard X-ray observation of X-1 confirms that it has an average 0.5-10 keV luminosity of 1.5e38 erg/s, is strongly variable (a factor of ~2 in >3 ks), and is spatially coincident (within 0.'23 +/-0.'30) with the Wolf-Rayet (WR) star [MAC92] 17A in IC 10. The spectrum of X-1 is best fit by a power law with photon index of ~1.8 and a thermal plasma with kT~1.5...
Source: http://arxiv.org/abs/astro-ph/0310039v1
71
71
Jul 20, 2013
07/13
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 71
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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
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
favorite 0
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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
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
45
45
Sep 22, 2013
09/13
by
O. Almaini; J. S. Dunlop; C. J. Willott; D. M. Alexander; F. E. Bauer; C. T. Liu
texts
eye 45
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We present evidence for a positive angular correlation between bright submillimetre sources and low-redshift galaxies. The study was conducted using 39 sources selected from 3 contiguous, flux-limited SCUBA surveys, cross-correlated with optical field galaxies with magnitudes R 10mJy. We conduct Monte-Carlo simulations of clustered submm populations, and find that the probability of obtaining these correlations by chance is less than 0.4 per cent. The results may suggest that a larger than...
Source: http://arxiv.org/abs/astro-ph/0501169v1
3
3.0
Jun 29, 2018
06/18
by
S. Schulze; T. Krühler; G. Leloudas; J. Gorosabel; A. Mehner; J. Buchner; S. Kim; E. Ibar; R. Amorín; R. Herrero-Illana; J. P. Anderson; F. E. Bauer; L. Christensen; M. de Pasquale; A. de Ugarte Postigo; A. Gallazzi; J. Hjorth; N. Morrell; D. Malesani; M. Sparre; B. Stalder; A. A. Stark; C. C. Thöne; J. C. Wheeler
texts
eye 3
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The SUperluminous Supernova Host galaxIES (SUSHIES) survey aims to provide strong new constraints on the progenitors of superluminous supernovae (SLSNe) by understanding the relationship to their host galaxies. Here, we present the photometric properties of 53 H-poor and 16 H-rich SLSN host galaxies out to $z\sim4$. We model the spectral energy distributions of the hosts to derive physical properties (e.g., stellar mass and star-formation-rate distribution functions), which we compare with...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1612.05978
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
74
74
Sep 17, 2013
09/13
by
B. Luo; W. N. Brandt; A. T. Steffen; F. E. Bauer
texts
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
11
11
Jun 26, 2018
06/18
by
M. Brightman; M. Balokovic; D. Stern; P. Arevalo; D. R. Ballantyne; F. E. Bauer; S. E. Boggs; W. W. Craig; F. E. Christensen; A. Comastri; F. Fuerst; P. Gandhi; C. J. Hailey; F. A. Harrison; R. C. Hickox; M. Koss; S. LaMassa; S. Puccetti; E. Rivers; R. Vasudevan; D. J. Walton; W. W. Zhang
texts
eye 11
favorite 0
comment 0
The covering factor of Compton-thick obscuring material associated with the torus in active galactic nuclei (AGN) is at present best understood through the fraction of sources exhibiting Compton-thick absorption along the line of sight ($N_{H}>1.5\times10^{24}$ cm$^{-2}$) in the X-ray band, which reveals the average covering factor. Determining this Compton-thick fraction is difficult however, due to the extreme obscuration. With its spectral coverage at hard X-rays ($>$10 keV), NuSTAR is...
Topics: High Energy Astrophysical Phenomena, Astrophysics
Source: http://arxiv.org/abs/1502.07353
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
texts
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
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
texts
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
40
40
Sep 18, 2013
09/13
by
P. Santini; D. J. Rosario; L. Shao; D. Lutz; R. Maiolino; D. M. Alexander; B. Altieri; P. Andreani; H. Aussel; F. E. Bauer; S. Berta; A. Bongiovanni; W. N. Brandt; M. Brusa; J. Cepa; A. Cimatti; E. Daddi; D. Elbaz; A. Fontana; N. M. Forster Schreiber; R. Genzel; A. Grazian; E. Le Floc'h; B. Magnelli; V. Mainieri; R. Nordon; A. M. Perez Garcia; A. Poglitsch; P. Popesso; F. Pozzi; L. Riguccini; G. Rodighiero; M. Salvato; M. Sanchez-Portal; E. Sturm; L. J. Tacconi; I. Valtchanov; S. Wuyts
texts
eye 40
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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
35
35
Sep 18, 2013
09/13
by
D. M. Alexander; F. E. Bauer; W. N. Brandt; A. E. Hornschemeier; C. Vignali; G. P. Garmire; D. P. Schneider
texts
eye 35
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We provide constraints on optically faint (I>=24) X-ray sources, z>6 AGN, Very Red Objects (VROs; I-K>=4), and optically faint radio sources using the 1 Ms Chandra Deep Field North survey. We argue that the majority of the optically faint X-ray sources are obscured AGN at z=1-3. These sources comprise up to 50% of the X-ray detected AGN. Approximately 30% of the optically faint X-ray sources have properties consistent with those expected for z>6 AGN; however we argue that the...
Source: http://arxiv.org/abs/astro-ph/0202044v1
33
33
Sep 22, 2013
09/13
by
R. M. Bandyopadhyay; J. C. A. Miller-Jones; K. M. Blundell; F. E. Bauer; Ph. Podsiadlowski; Q. D. Wang; S. Rappaport; E. Pfahl
texts
eye 33
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We present results from the first near-IR imaging of the weak X-ray sources discovered in the Chandra/ACIS-I survey (Wang et al. 2002) towards the Galactic Centre (GC). These ~800 discrete sources, which contribute significantly to the GC X-ray emission, represent an important and previously unknown population within the Galaxy. From our VLT observations we will identify likely IR counterparts to a sample of the hardest sources, which are most likely X-ray binaries. With these data we can place...
Source: http://arxiv.org/abs/astro-ph/0501327v1
66
66
Sep 18, 2013
09/13
by
D. M. Alexander; F. E. Bauer; S. C. Chapman; I. Smail; A. W. Blain; W. N. Brandt; R. J. Ivison
texts
eye 66
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Deep SCUBA surveys have uncovered a large population of ultra-luminous galaxies at z>1. These sources are often assumed to be starburst galaxies, but there is growing evidence that a substantial fraction host an AGN (i.e., an accreting super-massive black hole). We present here possibly the strongest evidence for this viewpoint to date: the combination of ultra-deep X-ray observations (the 2 Ms Chandra Deep Field-North) and deep optical spectroscopic data. We argue that upward of 38% of...
Source: http://arxiv.org/abs/astro-ph/0401129v1
6
6.0
Jun 30, 2018
06/18
by
N. Laporte; A. Streblyanska; S. Kim; R. Pelló; F. E. Bauer; D. Bina; G. Brammer; M. A. De Leo; L. Infante; I. Pérez-Fournon
texts
eye 6
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(Abridged) The HST Frontier Fields project started at the end of 2013 with the aim of providing extremely deep images of 6 massive galaxy clusters. One of the main goals of this program is to push several telescopes to their limits in order to provide the best current view of the earliest stages of the Universe. We present a detailed analysis of $z$$\sim$8 objects behind the HFFs lensing cluster, MACS0416-2403, combining 0.3-1.6 $\mu$m imaging from HST, ground-based $K_s$ imaging from VLT...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1412.1089
56
56
Sep 21, 2013
09/13
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 56
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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
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
3
3.0
Jun 30, 2018
06/18
by
S. Schulze; D. Malesani; A. Cucchiara; N. R. Tanvir; T. Krühler; A. de Ugarte Postigo; G. Leloudas; J. Lyman; D. Bersier; K. Wiersema; D. A. Perley; P. Schady; J. Gorosabel; J. P. Anderson; A. J. Castro-Tirado; S. B. Cenko; A. De Cia; L. E. Ellerbroek; J. P. U. Fynbo; J. Greiner; J. Hjorth; D. A. Kann; L. Kaper; S. Klose; A. J. Levan; S. Martín; P. T. O'Brien; K. L. Page; G. Pignata; S. Rapaport; R. Sánchez-Ramírez; J. Sollerman; I. A. Smith; M. Sparre; C. C. Thöne; D. J. Watson; D. Xu; F....
texts
eye 3
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At low redshift, a handful of gamma-ray bursts (GRBs) have been discovered with peak luminosities ($L_{\rm iso} < 10^{48.5}~\rm{erg\,s}^{-1}$) substantially lower than the average of the more distant ones ($L_{\rm iso} > 10^{49.5}~\rm{erg\,s}^{-1}$). The properties of several low-luminosity (low-$L$) GRBs indicate that they can be due to shock break-out, as opposed to the emission from ultrarelativistic jets. Owing to this, it is highly debated how both populations are connected, and...
Topics: High Energy Astrophysical Phenomena, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1401.3774
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
114
114
Jul 20, 2013
07/13
by
E. A. Richards; F. E. Bauer; A. J. Barger; L. Cowie
texts
eye 114
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Using a combination of radio and optical imaging at 0.1\arcs to 0.2\arcs resolution with the VLA/MERLIN and HST has led to a breakthrough in our understanding of radio emission from distant (0.1 4-6) and submillimeter sources with S > 2 mJy at 850 microns as measured with SCUBA on the JCMT. The far-infrared luminosities of these galaxies exceeds even the most intense starbursts found in the local universe (e.g., Arp 220), suggesting they are in the process of converting the bulk of their...
Source: http://arxiv.org/abs/astro-ph/9910497v2
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
texts
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
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
texts
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
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
5
5.0
Jun 29, 2018
06/18
by
L. Tartaglia; A. Pastorello; M. Sullivan; C. Baltay; D. Rabinowitz; P. Nugent; A. J. Drake; S. G. Djorgovski; A. Gal-Yam; S. Fabrika; E. A. Barsukova; V. P. Goranskij; A. F. Valeev; T. Fatkhullin; S. Schulze; A. Mehner; F. E. Bauer; S. Taubenberger; J. Nordin; S. Valenti; D. A. Howell; S. Benetti; E. Cappellaro; G. Fasano; N. Elias-Rosa; M. Barbieri; D. Bettoni; A. Harutyunyan; T. Kangas; E. Kankare; J. C. Martin; S. Mattila; A. Morales-Garoffolo; P. Ochner; Umaa D. Rebbapragada; G. Terreran;...
texts
eye 5
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We report photometric and spectroscopic observations of the optical transient LSQ13zm. Historical data reveal the presence of an eruptive episode (that we label as `2013a') followed by a much brighter outburst (`2013b') three weeks later, that we argue to be the genuine supernova explosion. This sequence of events closely resemble those observed for SN2010mc and (in 2012) SN2009ip. The absolute magnitude reached by LSQ13zm during 2013a ($M_R=-14.87\pm0.25\,\rm{mag}$) is comparable with those of...
Topics: Astrophysics, High Energy Astrophysical Phenomena, Solar and Stellar Astrophysics
Source: http://arxiv.org/abs/1604.00013
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
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
49
49
Sep 18, 2013
09/13
by
E. Daddi; M. Dickinson; G. Morrison; R. Chary; A. Cimatti; D. Elbaz; D. Frayer; A. Renzini; A. Pope; D. M. Alexander; F. E. Bauer; M. Giavalisco; M. Huynh; J. Kurk; M. Mignoli
texts
eye 49
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Examining a sample of massive galaxies at 1.410^{11}L_sun, show a mid-IR excess which is likely due to the presence of obscured active nuclei, as shown in a companion paper. There is a tight and roughly linear correlation between stellar mass and SFR for 24um-detected galaxies. For a given mass, the SFR at z=2 was larger by a factor of ~4 and ~30 relative to that in star forming galaxies at z=1 and z=0, respectively. Typical ultraluminous infrared galaxies (ULIRGs) at z=2 are relatively...
Source: http://arxiv.org/abs/0705.2831v2
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44
Sep 18, 2013
09/13
by
E. Daddi; D. M. Alexander; M. Dickinson; R. Gilli; A. Renzini; D. Elbaz; A. Cimatti; R. Chary; D. Frayer; F. E. Bauer; W. N. Brandt; M. Giavalisco; N. A. Grogin; M. Huynh; J. Kurk; M. Mignoli; G. Morrison; A. Pope; S. Ravindranath
texts
eye 44
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Approximately 20-30% of 1.46.2 keV. The stacked X-ray spectrum rises steeply at >10 keV, suggesting that these sources host Compton-thick Active Galactic Nuclei (AGNs) with column densities N_H~10^{24} cm^-2 and an average, unobscured X-ray luminosity L_{2-8 keV}~(1-4)x10^43 erg/s. Their sky density(~3200 deg^-2) and space density (~2.6x10^-4 Mpc^-3) are twice those of X-ray detected AGNs at z~2, and much larger than those of previously-known Compton thick sources at similar redshifts. The...
Source: http://arxiv.org/abs/0705.2832v2
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
8
8.0
Jun 30, 2018
06/18
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 8
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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
