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相关论文: The FIRST Bright Quasar Survey III. The South Gala…

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In a spectroscopic follow-up to the VLA FIRST survey, the FIRST Bright Quasar Survey (FBQS) has found 29 radio-selected broad absorption line (BAL) quasars. This sample provides the first opportunity to study the properties of…

天体物理学 · 物理学 2014-10-13 R. H. Becker , R. L. White , M. D. Gregg , M. S. Brotherton , S. A. Laurent-Meuleisen , N. Arav

We have used the VLA FIRST survey and the APM catalog of the POSS-I plates as the basis for constructing a new radio-selected sample of optically bright quasars. This is the first radio-selected sample that is competitive in size with…

The FIRST Radio Survey provides a new resource for constructing a large quasar sample. With source positions accurate to better than 1\arcsec\ and a point source sensitivity limit of 1 mJy, it reaches 50 times deeper than previous radio…

The main goal of the FIRST-APM QSO Survey (FAQS) survey is to compile the most complete sample of Bright QSOs, located in the well optically investigated area of the sky covered by the Second Byurakan Survey (SBS). We do that through the…

天体物理学 · 物理学 2007-05-23 V. H. Chavushyan , V. O. Verkhodanov , R. Mujica , L. Carrasco

We present 13 Broad Absorption Line (BAL) quasars, including 12 new objects, which were identified in the Sloan Digital Sky Survey (SDSS) and matched within 2'' to sources in the FIRST radio survey catalog. The surface density of this…

We present the method and first results of a survey for high-redshift (z>3) radio-loud quasars, which is based on optical identifications of 2902 flat-spectrum radio sources with S(5GHz)>= 25mJy. The radio sample was defined over a 1600 sq…

天体物理学 · 物理学 2009-10-30 I. M. Hook , R. H. Becker , R. G. McMahon , R. L. White

We have built a sample of 74 radio-selected broad absorption line quasars from the Sloan Digital Sky Survey Data Release 5 (SDSS DR5) and Faint Images of the Radio Sky at Twenty Centimeters (FIRST), along with a well matched sample of 74…

宇宙学与河外天体物理 · 物理学 2015-05-30 Michael A. DiPompeo , Michael S. Brotherton , Carlos De Breuck , Sally Laurent-Muehleisen

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)…

天体物理学 · 物理学 2014-10-13 Paul C. Hewett , Craig B. Foltz

We investigate C IV broad absorption line (BAL) variability within a sample of 46 radio-loud quasars (RLQs), selected from SDSS/FIRST data to include both core-dominated (39) and lobe-dominated (7) objects. The sample consists primarily of…

宇宙学与河外天体物理 · 物理学 2015-06-19 C. A. Welling , B. P. Miller , W. N. Brandt , D. M. Capellupo , R. R. Gibson

The source catalogue for the LBQS and the FIRST Survey are compared in their regions of overlap. In the 270 deg^2 common to both surveys the LBQS contains \~100,000 stellar and ~40,000 non-stellar objects, while the FIRST catalogue contains…

天体物理学 · 物理学 2014-10-13 Paul C. Hewett , Craig B. Foltz , Frederic H. Chaffee

We have discovered a remarkable quasar, FIRST J101614.3+520916, whose optical spectrum shows unambiguous broad absorption features while its double-lobed radio morphology and luminosity clearly indicate a classic Fanaroff-Riley Type II…

We present the results of a multi-wavelength study of a sample of high-redshift Radio Loud (RL) Broad Absorption Line (BAL) quasars. This way we extend to higher redshift previous studies on the radio properties, and broadband optical…

(Abridged). We explore the fraction of radio loud quasars in the eHAQ+GAIA23 sample, which contains quasars from the High A(V) Quasar (HAQ) Survey, the Extended High A(V) Quasar (eHAQ) Survey, and the Gaia quasar survey. All quasars in this…

星系天体物理 · 物理学 2024-01-08 S. Vejlgaard , J. P. U. Fynbo , K. E. Heintz , J. -K. Krogager , P. Møller , S. J. Geier , L. Christensen , G Ma

We present preliminary results from an investigation into broad absorption line (BAL) variability within a sample of 41 radio-loud quasars (RLQs). Using 28 new Hobby-Eberly Telescope (HET) spectra along with earlier Sloan Digital Sky Survey…

高能天体物理现象 · 物理学 2012-01-13 B. P. Miller , C. A. Welling , W. N. Brandt , R. R. Gibson

A substantial fraction of quasars display broad absorption lines (BALs) in their rest-frame ultraviolet spectra. While the origin of BALs is thought to be related to the accretion disc wind, it remains unclear whether the observed ratio of…

高能天体物理现象 · 物理学 2024-05-22 Takayuki J. Hayashi , Akihiro Doi , Hiroshi Nagai

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…

If broad absorption line (BAL) quasars represent a high covering fraction evolutionary state (even if this is not the sole factor governing the presence of BALs), it is expected that they should show an excess of mid-infrared radiation…

宇宙学与河外天体物理 · 物理学 2015-06-12 M. A. DiPompeo , J. C. Runnoe , M. S. Brotherton , A. D. Myers

We have searched the archived, pointed ROSAT Position Sensitive Proportional Counter data for blazars by correlating the WGACAT X-ray database with several publicly available radio catalogs, restricting our candidate list to serendipitous…

天体物理学 · 物理学 2008-11-26 H. Landt , P. Padovani , E. Perlman , P. Giommi , H. Bignall , A. Tzioumis

The main goal of the FIRST-APM QSO Survey (FAQS) survey is to compile the most complete sample of Bright QSOs, located in the area covered by the Second Byurakan Survey (SBS). Here we report the first results of an ongoing study based on…

天体物理学 · 物理学 2019-08-15 V. H. Chavushyan , R. Mújica , L. Carrasco , J. R. Valdés , O. V. Verkhodanov , J. Stepanian

In this paper we present the first results of a deep spectroscopic survey of faint quasars in the Sloan Digital Sky Survey (SDSS) Southern Survey, a deep survey carried out by repeatedly imaging a 270 deg^2 area. Quasar candidates were…

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