89
89
Sep 21, 2013
09/13
by
L. Zappacosta; R. Maiolino; F. Mannucci; R. Gilli; P. Schuecker
texts
eye 89
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We have analyzed the soft X-ray emission in a wide area of the Sculptor supercluster by using overlapping ROSAT PSPC pointings. After subtraction of the point sources we have found evidence for extended, diffuse soft X-ray emission. We have investigated the nature of such extended emission through the cross-correlation with the density of galaxies as inferred from the Muenster Redshift Survey. In particular we have analyzed the correlation as a function of the temperature of the X-ray emitting...
Source: http://arxiv.org/abs/astro-ph/0402575v2
48
48
Sep 19, 2013
09/13
by
F. Mannucci; G. Bonnoli; L. Zappacosta; R. Maiolino; M. Pedani
texts
eye 48
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We present the results of spectroscopic observations of galaxies associated with the diffuse X-ray emitting structure discovered by Zappacosta et al. (2002). After measuring the redshifts of 161 galaxies, we confirm an overdensity of galaxies with projected dimensions of at least 2 Mpc, determine its spectroscopic redshift in z=0.401+/-0.002, and show that it is spatially coincident with the diffuse X-ray emission. This confirms the original claim that this X-ray emission has an extragalactic...
Source: http://arxiv.org/abs/astro-ph/0703076v2
98
98
Sep 18, 2013
09/13
by
L. Zappacosta; R. Maiolino; F. Mannucci; R. Gilli; A. Finoguenov; A. Ferrara
texts
eye 98
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Several popular cosmological models predict that most of the baryonic mass in the local universe is located in filamentary and sheet-like structures associated with groups and clusters of galaxies. This gas is expected to be gravitationally heated to ~10^6 K and therefore emitting in the soft X-rays. We have investigated three fields with large scale structures of galaxies at redshifts 0.1, 0.45, 0.79 and found signatures of warm-hot thermal emission (kT < 1 keV) correlated with the...
Source: http://arxiv.org/abs/astro-ph/0401202v1
54
54
Sep 22, 2013
09/13
by
L. Zappacosta; R. Maiolino; A. Finoguenov; F. Mannucci; R. Gilli; A. Ferrara
texts
eye 54
favorite 0
comment 0
We have identified a large-scale structure traced by galaxies at z=0.8, within the Lockman Hole, by means of multi-object spectroscopic observations. By using deep XMM images we have investigated the soft X-ray emission from the Warm-Hot Intergalactic Medium (WHIM) expected to be associated with this large-scale structure and we set a tight upper limit to its flux in the very soft 0.2-0.4 keV band. The non-detection requires the WHIM at these redshifts to be cooler than 0.1 keV. Combined with...
Source: http://arxiv.org/abs/astro-ph/0501402v1
40
40
Sep 23, 2013
09/13
by
F. Gastaldello; D. Buote; P. Humphrey; L. Zappacosta; J. Bullock; F. Brighenti; W. Mathews
texts
eye 40
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The Chandra and XMM data for a sample of 19 relaxed groups/poor clusters, covering the temperature range 1-3 keV and selected to have the best available data, reveal a remarkable similarity in their temperature profile: cool cores outside of which the temperatures reach a peak for radii less than 0.1 of the virial radius and then decline. We fitted the derived mass profiles using an NFW model, which provides a good fit to the data when accounting for the central galaxy in the inner region. The...
Source: http://arxiv.org/abs/astro-ph/0510592v2
57
57
Sep 18, 2013
09/13
by
G. Matt; D. Porquet; S. Bianchi; S. Falocco; R. Maiolino; J. N. Reeves; L. Zappacosta
texts
eye 57
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Q0056-363 is the most powerful X-ray quasar known to exhibit a broad, likely relativistic iron line (Porquet & Reeves 2003). It has been observed twice by XMM-$Newton$, three and half years apart (July 2000 and December 2003). In the second observation, the UV and soft X-ray fluxes were fainter, the hard X-ray power law flatter, and the iron line equivalent width (EW) smaller than in the 2000 observation. These variations can all be explained, at least qualitatively, if the disc is...
Source: http://arxiv.org/abs/astro-ph/0502323v1
47
47
Sep 23, 2013
09/13
by
L. Zappacosta; D. A. Buote; F. Gastaldello; P. J. Humphrey; J. Bullock; F. Brighenti; W. Mathews
texts
eye 47
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We have analyzed an XMM-Newton observation of the cluster Abell 2589. Apart from a low-level asymmetry in the central region, the cluster appears very relaxed and does not show presence of a central AGN. We derived constraints for the radial temperature, density and, assuming hydrostatic equilibrium, mass profiles. We find that the best fit to the dark matter profile is given by the Sersic-like profile proposed by Navarro et al. (2004). The NFW model does not provide a good fit. We also tested...
Source: http://arxiv.org/abs/astro-ph/0510632v1
33
33
Sep 19, 2013
09/13
by
W. G. Mathews; F. Brighenti; A. Faltenbacher; D. A. Buote; P. J. Humphrey; F. Gastaldello; L. Zappacosta
texts
eye 33
favorite 0
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The enormous range of X-ray luminosities among elliptical galaxies with similar optical luminosities can be attributed to large scatter and systematic variations in the dark halo mass determined from X-ray observations. The mean halo mass decreases sharply with both the X-ray and K-band luminosities. Smaller halos contain less diffuse hot gas and have lower X-ray luminosities. In addition the hot gas in low mass halos is more easily depleted by supernova-driven outflows, further lowering the...
Source: http://arxiv.org/abs/astro-ph/0610694v1
76
76
Sep 22, 2013
09/13
by
L. Zappacosta; F. Nicastro; R. Maiolino; G. Tagliaferri; D. A. Buote; T. Fang; P. J. Humphrey; F. Gastaldello
texts
eye 76
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We make use of a 500ks Chandra HRC-S/LETG spectrum of the blazar H2356-309, combined with a lower S/N spectrum of the same target, to search for the presence of warm-hot absorbing gas associated with two Large-Scale Structures (LSSs) crossed by this sightline at z=0.062 (the Pisces-Cetus Supercluster, PCS) and at z=0.128 ("Farther Sculptor Wall", FSW). No statistically significant (>=3sigma) individual absorption is detected from any of the strong He- or H-like transitions of C, O...
Source: http://arxiv.org/abs/1004.5359v1
41
41
Sep 19, 2013
09/13
by
L. Zappacosta; F. Mannucci; R. Maiolino; R. Gilli; A. Ferrara; A. Finoguenov; N. M. Nagar; D. J. Axon
texts
eye 41
favorite 0
comment 0
Several popular cosmological models predict that most of the baryonic mass in the local universe is located in filamentary and sheet-like structures associated with galaxy overdensities. This gas is expected to be gravitationally heated to ~10^6 K and therefore emitting in the soft X-rays. We have detected diffuse soft X-ray structures in a high Galactic latitude ROSAT field after point source subtraction and correction for Galactic absorption. These diffuse structures have an X-ray energy...
Source: http://arxiv.org/abs/astro-ph/0208033v1
8
8.0
Jun 29, 2018
06/18
by
A. Lamastra; F. Fiore; D. Guetta; L. A. Antonelli; S. Colafrancesco; N. Menci; S. Puccetti; A. Stamerra; L. Zappacosta
texts
eye 8
favorite 0
comment 0
We compute the non-thermal emissions produced by relativistic particles accelerated by the AGN-driven shocks in NGC 1068, and we compare the model predictions with the observed gamma-ray and radio spectra . The former is contributed by pion decay, inverse Compton scattering, and bremsstrahlung, while the latter is produced by synchrotron radiation. We derive the gamma-ray and radio emissions by assuming the standard acceleration theory, and we discuss how our results compare with those...
Topics: Astrophysics, High Energy Astrophysical Phenomena
Source: http://arxiv.org/abs/1609.09664
3
3.0
Jun 30, 2018
06/18
by
E. Piconcelli; C. Vignali; S. Bianchi; L. Zappacosta; J. Fritz; G. Lanzuisi; G. Miniutti; A. Bongiorno; C. Feruglio; F. Fiore; R. Maiolino
texts
eye 3
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We present the first X-ray spectrum of a Hot dust-obscured galaxy (DOG), namely W1835+4355 at z ~ 2.3. Hot DOGs represent a very rare population of hyperluminous (>= 10^47 erg/s), dust-enshrouded objects at z > 2 recently discovered in the WISE All Sky Survey. The 40 ks XMM-Newton spectrum reveals a continuum as flat (Gamma ~ 0.8) as typically seen in heavily obscured AGN. This, along with the presence of strong Fe Kalpha emission, clearly suggests a reflection-dominated spectrum due to...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1412.3595
3
3.0
Jun 30, 2018
06/18
by
C. Feruglio; A. Bongiorno; F. Fiore; M. Krips; M. Brusa; E. Daddi; I. Gavignaud; R. Maiolino; E. Piconcelli; M. Sargent; C. Vignali; L. Zappacosta
texts
eye 3
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Understanding the relationship between the formation and evolution of galaxies and their central super massive black holes (SMBH) is one of the main topics in extragalactic astrophysics. Links and feedback may reciprocally affect both black hole and galaxy growth. Observations of the CO line at redshifts of 2-4 are crucial to investigate the gas mass, star formation activity and accretion onto SMBHs, as well as the effect of AGN feedback. Potential correlations between AGN and host galaxy...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1403.0853
14
14
Jun 27, 2018
06/18
by
C. Feruglio; F. Fiore; S. Carniani; E. Piconcelli; L. Zappacosta; A. Bongiorno; C. Cicone; R. Maiolino; A. Marconi; N. Menci; S. Puccetti; S. Veilleux
texts
eye 14
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We present the best sensitivity and angular resolution maps of the molecular disk and outflow of Mrk 231, as traced by CO observations obtained with IRAM/PdBI, and we analyze archival Chandra and NuSTAR observations. We constrain the physical properties of both the molecular disk and outflow, the presence of a highly-ionized ultra-fast nuclear wind, and their connection. The molecular outflow has a size of ~1 kpc, and extends in all directions around the nucleus, being more prominent along the...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1503.01481
52
52
Sep 22, 2013
09/13
by
F. Nicastro; M. Elvis; Y. Krongold; S. Mathur; A. Gupta; C. Danforth; X. Barcons; S. Borgani; E. Branchini; R. Cen; R. Davé; J. Kaastra; F. Paerels; L. Piro; J. M. Shull; Y. Takei; L. Zappacosta
texts
eye 52
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We present the first results from our pilot 500 ks Chandra-LETG Large Program observation of the soft X-ray brightest source in the z>=0.4 sky, the blazar 1ES 1553+113, aimed to secure the first uncontroversial detections of the missing baryons in the X-rays. We identify a total of 11 possible absorption lines, with single-line statistical significances between 2.2-4.1\sigma. Six of these lines are detected at high single-line statistical significance (3.6
Source: http://arxiv.org/abs/1210.7177v2
4
4.0
Jun 29, 2018
06/18
by
M. Bischetti; E. Piconcelli; G. Vietri; A. Bongiorno; F. Fiore; E. Sani; A. Marconi; F. Duras; L. Zappacosta; M. Brusa; A. Comastri; G. Cresci; C. Feruglio; E. Giallongo; F. La Franca; V. Mainieri; F. Mannucci; S. Martocchia; F. Ricci; R. Schneider; V. Testa; C. Vignali
texts
eye 4
favorite 0
comment 0
Models and observations suggest that both power and effects of AGN feedback should be maximised in hyper-luminous (L_Bol>10^47 erg/s) quasars, i.e. objects at the brightest end of the AGN luminosity function. We present the first results of a multi-wavelength observing program, focusing on a sample of WISE/SDSS selected hyper-luminous (WISSH) broad-line quasars at z~1.5-5. The WISSH quasars project has been designed to reveal the most energetic AGN-driven outflows, estimate their occurrence...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1612.03728
6
6.0
Jun 28, 2018
06/18
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
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 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
7
7.0
Jun 28, 2018
06/18
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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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
16
16
Jun 28, 2018
06/18
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
9
9.0
Jun 28, 2018
06/18
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 9
favorite 0
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
3
3.0
Jun 29, 2018
06/18
by
G. B. Lansbury; D. Stern; J. Aird; D. M. Alexander; C. Fuentes; F. A. Harrison; E. Treister; F. E. Bauer; J. A. Tomsick; M. Balokovic; A. Del Moro; P. Gandhi; M. Ajello; A. Annuar; D. R. Ballantyne; S. E. Boggs; N. Brandt; M. Brightman; C. J. Chen; F. E. Christensen; F. Civano; A. Comastri; W. W. Craig; K. Forster; B. W. Grefenstette; C. J. Hailey; R. Hickox; B. Jiang; H. Jun; M. Koss; S. Marchesi; A. D. Melo; J. R. Mullaney; G. Noirot; S. Schulze; D. J. Walton; L. Zappacosta; W. Zhang
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
14
14
Jun 28, 2018
06/18
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
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 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
9
9.0
Jun 28, 2018
06/18
by
F. A. Harrison; J. Aird; F. Civano; G. Lansbury; J. R. Mullaney; D. R. Ballantyne; D. M. Alexander; D. Stern; M. Ajello; D. Barret; F. E. Bauer; M. Balokovic; W. N. Brandt; M. Brightman; S. E. Boggs; F. E. Christensen; A. Comastri; W. W. Craig; A. Del Moro; K. Forster; P. Gandhi; P. Giommi; B. W. Grefenstette; C. J. Hailey; R. C. Hickox; A. Hornstrup; T. Kitaguchi; J. Koglin; B. Luo; K. K. Madsen; P. H. Mao; H. Miyasaka; K. Mori; M. Perri; M. Pivovaroff; S. Puccetti; V. Rana; E. Treister; D....
texts
eye 9
favorite 0
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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
