scholarly journals The XMM‐Newton Wide‐Field Survey in the COSMOS Field. IV. X‐Ray Spectral Properties of Active Galactic Nuclei

2007 ◽  
Vol 172 (1) ◽  
pp. 368-382 ◽  
Author(s):  
V. Mainieri ◽  
G. Hasinger ◽  
N. Cappelluti ◽  
M. Brusa ◽  
H. Brunner ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Spectral Properties ◽  
Field Survey ◽  
Galactic Nuclei ◽  
Wide Field ◽  
X Ray

scholarly journals OPTICAL SPECTRAL PROPERTIES OFSWIFTBURST ALERT TELESCOPE HARD X-RAY-SELECTED ACTIVE GALACTIC NUCLEI SOURCES

2010 ◽  
Vol 710 (1) ◽  
pp. 503-539 ◽  
Author(s):  
Lisa M. Winter ◽  
Karen T. Lewis ◽  
Michael Koss ◽  
Sylvain Veilleux ◽  
Brian Keeney ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Spectral Properties ◽  
Galactic Nuclei ◽  
X Ray

scholarly journals The spectral energy distributions of active galactic nuclei

2019 ◽  
Vol 15 (S341) ◽  
pp. 21-25
Author(s):  
M. J. I. Brown ◽  
K. J. Duncan ◽  
H. Landt ◽  
M. Kirk ◽  
C. Ricci ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Spectral Energy ◽  
Wide Field ◽  
Spectral Energy Distributions ◽  
Energy Distributions ◽  
Photometric Redshifts ◽  
X Ray ◽  
Ongoing Work ◽  
Prior Literature

AbstarctWe present ongoing work on the spectral energy distributions (SEDs) of active galactic nuclei (AGNs), derived from X-ray, ultraviolet, optical, infrared and radio photometry and spectroscopy. Our work is motivated by new wide-field imaging surveys that will identify vast numbers of AGNs, and by the need to benchmark AGN SED fitting codes. We have constructed 41 SEDs of individual AGNs and 80 additional SEDs that mimic Seyfert spectra. All of our SEDs span 0.09 to 30μm, while some extend into the X-ray and/or radio. We have tested the utility of the SEDs by using them to generate AGN photometric redshifts, and they outperform SEDs from the prior literature, including reduced redshift errors and flux density residuals.

scholarly journals The X‐Ray Spectral Properties and Variability of Luminous High‐Redshift Active Galactic Nuclei

2005 ◽  
Vol 630 (2) ◽  
pp. 729-739 ◽  
Author(s):  
O. Shemmer ◽  
W. N. Brandt ◽  
C. Vignali ◽  
D. P. Schneider ◽  
X. Fan ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Spectral Properties ◽  
High Redshift ◽  
Galactic Nuclei ◽  
X Ray

scholarly journals ROSAT Observations of Active Galactic Nuclei

1994 ◽  
Vol 159 ◽  
pp. 53-62 ◽  
Author(s):  
W. Brinkmann
Keyword(s):  
Active Galactic Nuclei ◽  
Spectral Properties ◽  
Galactic Nuclei ◽  
High Sensitivity ◽  
Good Energy Resolution ◽  
Ongoing Research ◽  
X Ray ◽  
Sky Survey ◽  
Good Energy ◽  
First Time

The large number of Active Galactive Nuclei detected for the first time through their X-ray emission in the ROSAT All Sky Survey as well as the first measurements of the X-ray emission of many previously known AGN provide a new unprecedented large basis for the statistical and morphological exploration of these objects.The soft energy range of the X-Ray Telescope, the good energy resolution of the PSPC detector, and the high sensitivity of the instrument further allows an investigation of the spectral properties of sources in this energetically important energy band.A short overview is given of the actual ongoing research concentrating on the study of the soft X-ray class properties of the various types of AGN.

Clumpy accretion flows in active galactic nuclei: X-ray variability and spectral properties

2010 ◽  
Author(s):  
W. Ishibashi ◽  
T. J.-L. Courvoisier ◽  
A. Comastri ◽  
L. Angelini ◽  
M. Cappi
Keyword(s):  
Active Galactic Nuclei ◽  
Spectral Properties ◽  
Galactic Nuclei ◽  
X Ray ◽  
Accretion Flows

scholarly journals Local AGN survey (LASr): I. Galaxy sample, infrared colour selection, and predictions for AGN within 100 Mpc

2020 ◽  
Vol 494 (2) ◽  
pp. 1784-1816
Author(s):  
D Asmus ◽  
C L Greenwell ◽  
P Gandhi ◽  
P G Boorman ◽  
J Aird ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Galactic Nuclei ◽  
Wide Field ◽  
X Ray ◽  
Sky Survey ◽  
Galaxy Sample ◽  
Redshift Survey ◽  
Infrared Survey

ABSTRACT To answer major questions on supermassive black hole (SMBH) and galaxy evolution, a complete census of SMBH growth, i.e. active galactic nuclei (AGN), is required. Thanks to all-sky surveys by the Wide-field Infrared Survey Explorer (WISE) and the Spectrum-Roentgen-Gamma (SRG) missions, this task is now feasible in the nearby Universe. We present a new survey, the Local AGN Survey (LASr), with the goal of identifying AGN unbiased against obscuration and determining the intrinsic Compton-thick (CT) fraction. We construct the most complete all-sky galaxy sample within 100 Mpc ($90{{\ \rm per\ cent}}$ completeness for log (M*/M⊙) ∼ 9.4), four times deeper than the current reference, the Two Micron All-Sky Survey Redshift Survey (2MRS), which misses ${\sim}20{{\ \rm per\ cent}}$ of known luminous AGN. These 49k galaxies serve as parent sample for LASr, called LASr-GPS. It contains 4.3k already known AGN, $\ge 82{{\ \rm per\ cent}}$ of these are estimated to have $L^\mathrm{nuc}(12\, \mu \mathrm{m})\lt 10^{42.3}$ erg s−1, i.e. are low-luminosity AGN. As a first method for identifying Seyfert-like AGN, we use WISE-based infrared colours, finding 221 galaxies at $L^\mathrm{nuc}(12\, \mu \mathrm{m})\ge 10^{42.3}$ erg s−1 to host an AGN at $90{{\ \rm per\ cent}}$ reliability. This includes 61 new AGN candidates and implies an optical type 2 fraction of 50–71 per cent. We quantify the efficiency of this technique and estimate the total number of AGN with $L^\mathrm{int}(\rm {2-10\,keV})\ge 10^{42}$ erg s−1 in the volume to be $362^{+145}_{-116}$ ($8.6^{+3.5}_{-2.8}\, \times$ 10−5 Mpc−3). X-ray brightness estimates indicate the CT fraction to be 40–55 per cent to explain the Swift non-detections of the infrared selected objects. One third of the AGN within 100 Mpc remain to be identified, and we discuss the prospects for the eROSITA all-sky survey to detect them.

scholarly journals The OPTX Project: Comparing the Optical and X-Ray Spectral Properties of Active Galactic Nuclei

2009 ◽  
Vol 5 (S267) ◽  
pp. 142-142
Author(s):  
Laura Trouille ◽  
Amy Barger
Keyword(s):  
Active Galactic Nuclei ◽  
Spectral Properties ◽  
Classification Scheme ◽  
Galactic Nuclei ◽  
Complete Sample ◽  
X Ray ◽  
Central Engine

AbstractUsing a uniformly selected and highly spectroscopically complete sample of Chandra X-ray sources, we show that one cannot use X-ray spectral classifications and optical spectral classifications equivalently. Until a better understanding is reached for how the X-ray and optical classifications relate to the obscuration of the central engine, the use of a mixed classification scheme can only complicate the interpretation of X-ray AGN samples.

scholarly journals 5. Atmospheres of Accretion Discs

1985 ◽  
Vol 19 (1) ◽  
pp. 515-519
Author(s):  
James E. Pringle
Keyword(s):  
Active Galactic Nuclei ◽  
Strong Interaction ◽  
Spectral Properties ◽  
Galactic Nuclei ◽  
High Energy ◽  
Observational Evidence ◽  
Accretion Discs ◽  
Theoretical Modelling ◽  
X Ray ◽  
Actual Observation

Accretion discs are a popular ingredient among theorists for modelling a number of high energy astronomical objects like quasars, active galactic nuclei (Rees 1984) and galactic X-ray sources (Levin and van der Heuvel 1983). However, the observational evidence (as opposed to the strong theoretical presumption) that accretion discs exist in these objects is weak, and in only one case has some attempt been made to argue the case for a disc on the basis of its spectral properties (Malkan 1983). Indeed the structure of accretion discs is sufficiently ill-understood that any progress in this area must rest on a strong interaction between theoretical modelling and the actual observation of accretion discs in action.

scholarly journals X-ray spectral properties of active galactic nuclei in the Chandra Deep Field South

2006 ◽  
Vol 451 (2) ◽  
pp. 457-474 ◽  
Author(s):  
P. Tozzi ◽  
R. Gilli ◽  
V. Mainieri ◽  
C. Norman ◽  
G. Risaliti ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Spectral Properties ◽  
Galactic Nuclei ◽  
X Ray
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