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Related papers: Low-Ionization BAL QSOs in Ultraluminous Infrared …

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We present a spectropolarimetric survey of 36 broad absorption line quasi-stellar objects (BAL QSOs). The continuum, absorption trough, and emission line polarization of BAL QSOs yield clues about their structure. We confirm that BAL QSOs…

Astrophysics · Physics 2009-10-31 P. M. Ogle , M. H. Cohen , J. S. Miller , H. D. Tran , R. W. Goodrich , A. R. Martel

Broad absorption lines seen in some quasars prove the existence of ionized plasma outflows from the accretion disk. Outflows together with powerful jets are important feedback processes. Understanding physics behind BAL outflows might be a…

Astrophysics of Galaxies · Physics 2015-04-13 M. Kunert-Bajraszewska , M. Ceglowski , C. Roskowinski , M. Gawronski

This paper provides a general reference for deriving the ionizations and metal abundances for absorption-line clouds in photoionization equilibrium with a QSO spectrum. The results include a quantitative assessment of the theoretical…

Astrophysics · Physics 2009-10-30 Fred Hamann

We report the discovery of five broad-absorption-line (BAL) QSOs in a complete sample of 111 ultraviolet excess (UVX) QSO candidates also detected in the NRAO VLA Sky Survey. All five BAL QSOs, which include two high-ionization BAL QSOs and…

Broad-band polarimetry and spectropolarimetry of a complete sample of 18 luminous AGNs (Lbol > 10^11.5 Lsun), selected in an orientation-independent way by warm infrared flux, shows that an orientation-dust-covering Unified Scheme like that…

Astrophysics · Physics 2007-05-23 Beverley J. Wills , Dean C. Hines

Broad Absorption Line Quasars (BAL QSOs) have been found to be associated with extremely compact radio sources. These reduced dimensions can be either due to projection effects or these objects might actually be intrinsically small.…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-31 F. M. Montenegro-Montes , K. -H. Mack , C. R. Benn , R. Carballo , D. Dallacasa , J. I. González-Serrano , J. Holt , F. Jiménez-Luján

Broad absorption line quasars (BAL QSOs) belong to a class of objects not well-understood as yet. Their UV spectra show BALs in the blue wings of the UV resonance lines, owing to ionized gas with outflow velocities up to 0.2 c. They can…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-17 G. Bruni , D. Dallacasa , K. -H. Mack , F. M. Montenegro-Montes , J. I. González-Serrano , J. Holt , F. Jiménez-Luján

We have discovered two low-ionization broad absorption line quasars in programs to obtain optical spectra for radio-selected quasar candidates from the VLA FIRST Survey (Becker, White, & Helfand 1995). Both belong to the extremely rare…

We are in the process of obtaining a complete sample of exploratory X-ray observations of broad absorption line (BAL) QSOs from the Large Bright Quasar Survey (LBQS). This survey is composed of short (5-7 ks) Chandra ACIS-S3 observations…

Astrophysics · Physics 2007-05-23 S. C. Gallagher , W. N. Brandt , G. Chartas , R. M. Sambruna

The physical properties and dynamical behavior of Broad Absorption Line (BAL) outflows are crucial themes in understanding the connections between galactic centers and their hosts. FeLoBALs (identified with the presence of low-ionization Fe…

Accounting for ~20% of the total QSO population, Broad Absorption Line QSOs are still an unsolved problem in the AGN context. They present wide troughs in the UV spectrum, due to material with velocities up to 0.2 c toward the observer. The…

Low-ionization Broad Absorption Line QSOs (LoBALs) are suspected to be merging systems in which extreme, AGN-driven outflows have been triggered. Whether or not LoBALs are uniquely associated with mergers, however, has yet to be…

Astrophysics of Galaxies · Physics 2023-06-07 Mariana S. Lazarova , Gabriela Canalizo , Mark Lacy , Wyatt Behn , Kaitlyn Raub , Vardha N. Bennert , Duncan Farrah

We study the host galaxies of four Iron Low-Ionization Broad Absorption-line Quasars (FeLoBALs) using Hubble Space Telescope imaging data, investigating the possibility that they represent a transition between an obscured AGN and an…

Astrophysics of Galaxies · Physics 2018-02-28 Daniel Lawther , Marianne Vestergaard , Xiaohui Fan

It is thought that a class of broad absorption line (BAL) QSOs, characterised by Fe absorption features in their UV spectra (called `FeLoBALs'), could mark a transition stage between the end of an obscured starburst event and a youthful QSO…

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

The broad absorption lines (BALs) of QSOs indicate abundances of heavy elements, relative to hydrogen, that are 1 to 2 orders of magnitude higher than the solar values. In at least one QSO, an especially large enhancement of phosphorus is…

Astrophysics · Physics 2009-10-28 Gregory A. Shields

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

A study of outflow (OF) and BAL systems in Mrk 231 (and in similar IR QSOs) is presented. This study is based mainly on 1D and 2D spectroscopy (obtained at La Palma/WHT, HST, IUE, ESO/NTT, KPNO, APO and CASLEO observatories) plus HST…

Astrophysics · Physics 2009-11-10 S. Lipari , R. Terlevich , W. Zheng , B. Garcia-Lorenzo , S. Sanches , M. Bergmann

In this work we present the first results of a study of BAL QSOs (at low and high redshift), based on very deep Gemini GMOS integral field spectroscopy. In particular, the results obtained for the nearest BAL IR QSO Mrk 231 are presented.…

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