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Related papers: X-ray selected BALQSOs

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Broad absorption line quasars (commonly termed BALQSOs) contain the most dramatic examples of AGN-driven winds. The high absorbing columns in these winds, ~10^24 cm^-2, ensure that BALQSOs are generally X-ray faint. This high X-ray…

Broad absorption line quasars (BALQSOs) are key objects for studying the structure and emission/absorption properties of AGN. However, despite their fundamental importance, the properties of BALQSOs are still not well understood. In order…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 A. Streblyanska , X. Barcons , F. J. Carrera , R. Gil-Merino

Most X-ray studies of BALQSOs found significant (N_H~10^{22-24} cm^{-2}) intrinsic column densities of gas absorbing an underlying typical power-law continuum emission, in agreement with expectations from radiatively driven accretion disk…

Astrophysics · Physics 2009-11-13 Margherita Giustini , Massimo Cappi , Cristian Vignali

We present the results from XMM-Newton observations of the highly optically polarized broad absorption line quasar (BALQSO) CSO 755. By analyzing its X-ray spectrum with a total of ~3000 photons we find that this source has an X-ray…

Astrophysics · Physics 2008-11-26 O. Shemmer , W. N. Brandt , S. C. Gallagher , C. Vignali , Th. Boller , G. Chartas , A. Comastri

Recent results from the ROSAT All-Sky Survey (RASS) have shown that broad absorption line (BAL) QSOs are either highly absorbed or underluminous in the soft X-ray bandpass. Here, we extend this work by analyzing all known bona fide BALQSOs…

Astrophysics · Physics 2009-10-28 Paul J. Green , Smita Mathur

We have carried out a survey with the Chandra X-ray Observatory of a sample of 10 optically bright broad absorption line (BAL) QSOs. Eight out of ten sources are detected. The 6 brightest X-ray sources have only high ionization BALs…

Astrophysics · Physics 2009-11-06 Paul J. Green , Thomas L. Aldcroft , Smita Mathur , Belinda J. Wilkes , Martin Elvis

We study the X-ray and optical properties of 16 Broad Absorption Line (BAL) quasars detected in about 3 degree square region common to the wide synoptic (W-1) component of the Canada-France-HawaiiTelescope Legacy Survey (CFHTLS) and the XMM…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 C. S. Stalin , R. Srianand , P. Petitjean

Recent results from the ROSAT All Sky Survey, and from deep ROSAT pointings reveal that broad absorption line quasars (BALQSOs) are weak in the soft X-ray bandpass (with optical-to-X-ray spectral slope alpha_{ox}>1.8) in comparison to QSOs…

Astrophysics · Physics 2007-05-23 Paul J. Green , Thomas L. Aldcroft , Smita Mathur , Norbert Schartel

We present the analysis and interpretation of a sample of eight ASCA observations of Broad Absorption Line Quasi-Stellar Objects (BALQSOs). This is the first moderate-sized sample of sensitive BALQSO observations above 2 keV, and the…

Astrophysics · Physics 2014-10-13 S. C. Gallagher , W. N. Brandt , R. M. Sambruna , S. Mathur , N. Yamasaki

There is growing evidence of a higher intrinsic fraction of broad absorption line quasars (BALQSOs) than that obtained in optical surveys, on which most previous X-ray studies of BALQSOs have focused. Here we present Chandra observations of…

High Energy Astrophysical Phenomena · Physics 2014-04-21 Leah K. Morabito , Xinyu Dai , Karen M. Leighly , Gregory R. Sivakoff , Francesco Shankar

It is been known for more than a decade that BALQSOs (broad absorption line quasars) are highly attenuated in the X-ray regime compared to other quasars, especially in the soft band ($< $ 1 keV). Using X-ray selection techniques we have…

Astrophysics · Physics 2009-11-13 Kajal K. Ghosh , Brian Punsly

We present $\it {ASCA}$ observations of the z=1.98 prototype BALQSO: PHL5200. The source was detected in both SIS and GIS. A power-law spectrum ($\alpha_E = 0.6^{+0.9}_{-0.6}$) with large intrinsic absorption (N$_H = 1.3^{+2.3}_{-1.1}…

Astrophysics · Physics 2007-05-23 Smita Mathur , Martin Elvis , K. P. Singh

For the population of QSOs with broad ultraviolet absorption lines, we are just beginning to accumulate X-ray observations with enough counts for spectral analysis at CCD resolution. From a sample of eight QSOs [including four Broad…

Astrophysics · Physics 2014-10-13 S. C. Gallagher , W. N. Brandt , G. Chartas , G. Garmire

BAL QSOs are notoriously faint X-ray sources, presumably due to extreme intrinsic absorption. However, several objects have begun to appear through the obscuration with recent X-ray observations by Chandra and ASCA. Where enough counts are…

Astrophysics · Physics 2007-05-23 S. C. Gallagher , W. N. Brandt , G. Chartas , G. P. Garmire

Recent studies of QSOs with ROSAT suggest the existence of a significant population of Soft X-ray Weak QSOs (SXW QSOs) where the soft X-ray flux is ~ 10-30 times smaller than in typical QSOs. As a first step in a systematic study of these…

Astrophysics · Physics 2008-11-26 W. N. Brandt , A. Laor , Beverley J. Wills

Recent observations of Broad Absorption Line (BAL) quasars demonstrated that the soft X-ray emission of these objects is extremely weak and convincing evidence for very strong absorption by a high column density (~ 10^23.5 cm^-2) was…

Astrophysics · Physics 2009-10-31 T. G. Wang , W. Brinkmann , W. Yuan , J. X. Wang , Y. Y. Zhou

Broad absorption line (BAL) quasars are often considered X-ray weak relative to their optical/UV luminosity, whether intrinsically (i.e., the coronal emission is fainter) or due to large column densities of absorbing material. The SDSS-V is…

Very long (172 ks effective exposure time) observations of the BALQSO LBQS 2212-1759 with XMM-Newton yield a stringent upper-limit on its 0.2-10 keV (rest- frame 0.64-32.2 keV) flux, F < 6 E-17 erg/cm2/s, while simultaneous UV and optical…

Astrophysics · Physics 2009-11-11 Jean Clavel , Norbert Schartel , Laura Tomas

A sample of 67 Broad Absorption Line quasars (BALQSOs) from the Large Bright Quasar Survey (LBQS) is used to estimate the observed and intrinsic fraction of BAL quasars in optically--selected samples at intermediate (B_J \simeq 18.5)…

Astrophysics · Physics 2014-10-13 Paul C. Hewett , Craig B. Foltz

We compile a large sample of broad absorption lines (BAL) quasars with X-ray observations from the \xmm archive data and Sloan Digital Sky Survey Data Release 5. The sample consists of 41 BAL QSOs. Among 26 BAL quasars detected in X-ray,…

Astrophysics · Physics 2008-12-18 LuLu Fan , HuiYuan Wang , Tinggui Wang , Junxian Wang , Xiaobo Dong , Kai Zhang , Fuzhen Cheng
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