scholarly journals Jet-linked X-ray emission in radio-loud broad absorption line (BAL) quasars

2012 ◽  
Vol 8 (S290) ◽  
pp. 243-244
Author(s):  
M. Kunert-Bajraszewska ◽  
K. Katarzyński ◽  
A. Janiuk ◽  
M. Cegłowski
Keyword(s):  
Absorption Line ◽  
Large Scale ◽  
Large Fraction ◽  
Spectral Energy Distribution ◽  
Compact Objects ◽  
Spectral Energy ◽  
Broad Absorption ◽  
X Ray ◽  
Broad Absorption Line ◽  
Inverse Compton

AbstractWe have applied theoretical models to explain spectral energy distribution (SED) of three radio-loud broad absorption line (BAL) quasars: an extended hybrid object PG 1004+130 and two compact sources 1045+352 and 3C270.1. We calculate the emission from the very inner part of the sources which accounts for more than 90% of the observed X-ray radiation. In our analysis we consider a scenario in which the observed X-ray emission comes from the inverse-Compton (IC) scattering inside a jet and from the accretion disk corona. The compact objects 1045+352 and 3C270.1 are high-redshift quasars (z = 1.604 and 1.532 respectively), with strong radio cores. We argue that in the case of these two sources a non-thermal, inverse-Compton emission from the innermost parts of the jet can explain a large fraction of the observed X-ray emission. The large scale object PG 1004+130 with a peculiar radio morphology is a low-redshift (z = 0.24), lobe-dominated BAL quasar with a weak radio core. In this case simulated inverse-Compton X-ray emission of the jet is relatively low. However, the corona emission appears strong enough to explain the observed X-ray spectrum of this object.

scholarly journals Radio through X‐Ray Spectral Energy Distributions of 38 Broad Absorption Line Quasars

2007 ◽  
Vol 665 (1) ◽  
pp. 157-173 ◽  
Author(s):  
S. C. Gallagher ◽  
D. C. Hines ◽  
Myra Blaylock ◽  
R. S. Priddey ◽  
W. N. Brandt ◽  
...  
Keyword(s):  
Absorption Line ◽  
Spectral Energy ◽  
Spectral Energy Distributions ◽  
Energy Distributions ◽  
Broad Absorption ◽  
X Ray ◽  
Broad Absorption Line

scholarly journals The Frequency of Intrinsic X-Ray Weakness among Broad Absorption Line Quasars

2018 ◽  
Vol 859 (2) ◽  
pp. 113 ◽  
Author(s):  
Hezhen Liu ◽  
B. Luo ◽  
W. N. Brandt ◽  
S. C. Gallagher ◽  
G. P. Garmire
Keyword(s):  
Absorption Line ◽  
Broad Absorption ◽  
X Ray ◽  
Broad Absorption Line

scholarly journals On the absorption of X-ray bright broad absorption line quasars

2008 ◽  
Vol 491 (2) ◽  
pp. 425-434 ◽  
Author(s):  
M. Giustini ◽  
M. Cappi ◽  
C. Vignali
Keyword(s):  
Absorption Line ◽  
Broad Absorption ◽  
X Ray ◽  
Broad Absorption Line

scholarly journals NuSTARREVEALS AN INTRINSICALLY X-RAY WEAK BROAD ABSORPTION LINE QUASAR IN THE ULTRALUMINOUS INFRARED GALAXY MARKARIAN 231

2014 ◽  
Vol 785 (1) ◽  
pp. 19 ◽  
Author(s):  
Stacy H. Teng ◽  
W. N. Brandt ◽  
F. A. Harrison ◽  
B. Luo ◽  
D. M. Alexander ◽  
...  
Keyword(s):  
Absorption Line ◽  
Broad Absorption ◽  
X Ray ◽  
Infrared Galaxy ◽  
Broad Absorption Line ◽  
Ultraluminous Infrared Galaxy

scholarly journals ACHANDRASURVEY OF THE X-RAY PROPERTIES OF BROAD ABSORPTION LINE RADIO-LOUD QUASARS

2009 ◽  
Vol 702 (2) ◽  
pp. 911-928 ◽  
Author(s):  
B. P. Miller ◽  
W. N. Brandt ◽  
R. R. Gibson ◽  
G. P. Garmire ◽  
O. Shemmer
Keyword(s):  
Absorption Line ◽  
Broad Absorption ◽  
X Ray ◽  
Broad Absorption Line

scholarly journals The nature of the unassociated 2FGL sources

2014 ◽  
Vol 10 (S313) ◽  
pp. 91-92
Author(s):  
T. Pursimo ◽  
R. Ojha ◽  
E. Ferrara ◽  
F. Acero ◽  
H. Johnston ◽  
...  
Keyword(s):  
Spectral Energy Distribution ◽  
Low Frequency ◽  
Spectral Energy ◽  
High Frequency Peak ◽  
X Ray ◽  
Frequency Peak ◽  
Inverse Compton ◽  
Multi Wavelength ◽  
Error Circle

AbstractThe majority of Fermi-LAT detected (2FGL) sources are AGN, mostly blazars. However, the second largest category in the 2FGL are unassociated sources (~30% or 575 sources), whose multi-wavelength counterpart is either inconclusive or absent. Follow-up observations and archival data at X-ray, optical, and radio frequencies suggest that many unassociated 2FGL sources are strong candidates to be AGN. Typical observed characteristics of 2FGL detected AGN include variability at all frequencies and a spectral energy distribution (SED) with two “bumps”; a low-frequency synchrotron peak in the radio to optical/X-ray region and a high-frequency peak, possibly due to synchrotron self-Compton or Inverse Compton processes, that extends up to TeV energies. We present optical follow-up observations of a sample of Fermi unassociated sources with one or more potential X-ray counterparts detected within the LAT error circle.

scholarly journals ULTRAVIOLET/X-RAY VARIABILITY AND THE EXTENDED X-RAY EMISSION OF THE RADIO-LOUD BROAD ABSORPTION LINE QUASAR PG 1004+130

2015 ◽  
Vol 806 (2) ◽  
pp. 210 ◽  
Author(s):  
A. E. Scott ◽  
W. N. Brandt ◽  
B. P. Miller ◽  
B. Luo ◽  
S. C. Gallagher
Keyword(s):  
Absorption Line ◽  
Broad Absorption ◽  
X Ray ◽  
Broad Absorption Line

scholarly journals Photometric redshifts for X-ray-selected active galactic nuclei in the eROSITA era

2019 ◽  
Vol 489 (1) ◽  
pp. 663-680 ◽  
Author(s):  
M Brescia ◽  
M Salvato ◽  
S Cavuoti ◽  
T T Ananna ◽  
G Riccio ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Large Fraction ◽  
Spectral Energy Distribution ◽  
Galactic Nuclei ◽  
Training Sample ◽  
Spectral Energy ◽  
Ancillary Data ◽  
Photometric Redshifts ◽  
X Ray

ABSTRACT With the launch of eROSITA (extended Roentgen Survey with an Imaging Telescope Array), successfully occurred on 2019 July 13, we are facing the challenge of computing reliable photometric redshifts for 3 million of active galactic nuclei (AGNs) over the entire sky, having available only patchy and inhomogeneous ancillary data. While we have a good understanding of the photo-z quality obtainable for AGN using spectral energy distribution (SED)-fitting technique, we tested the capability of machine learning (ML), usually reliable in computing photo-z for QSO in wide and shallow areas with rich spectroscopic samples. Using MLPQNA as example of ML, we computed photo-z for the X-ray-selected sources in Stripe 82X, using the publicly available photometric and spectroscopic catalogues. Stripe 82X is at least as deep as eROSITA will be and wide enough to include also rare and bright AGNs. In addition, the availability of ancillary data mimics what can be available in the whole sky. We found that when optical, and near- and mid-infrared data are available, ML and SED fitting perform comparably well in terms of overall accuracy, realistic redshift probability density functions, and fraction of outliers, although they are not the same for the two methods. The results could further improve if the photometry available is accurate and including morphological information. Assuming that we can gather sufficient spectroscopy to build a representative training sample, with the current photometry coverage we can obtain reliable photo-z for a large fraction of sources in the Southern hemisphere well before the spectroscopic follow-up, thus timely enabling the eROSITA science return. The photo-z catalogue is released here.

The X‐Ray Absorber in Broad Absorption Line Quasars

2000 ◽  
Vol 545 (1) ◽  
pp. 77-85 ◽  
Author(s):  
T. G. Wang ◽  
W. Brinkmann ◽  
W. Yuan ◽  
J. X. Wang ◽  
Y. Y. Zhou
Keyword(s):  
Absorption Line ◽  
Broad Absorption ◽  
X Ray ◽  
Broad Absorption Line
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