SDSS 0956+5128: A BROAD-LINE QUASAR WITH EXTREME VELOCITY OFFSETS
Open Access
- 12 October 2012
- journal article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 759 (1), 24
- https://doi.org/10.1088/0004-637x/759/1/24
Abstract
We report on the discovery of a Type 1 quasar, SDSS 0956+5128, with a surprising combination of extreme velocity offsets. SDSS 0956+5128 is a broad-lined quasar exhibiting emission lines at three substantially different redshifts: a systemic redshift of z ~ 0.714 based on narrow emission lines, a broad Mg II emission line centered 1200 km s–1 bluer than the systemic velocity, at z ~ 0.707, and broad Hα and Hβ emission lines centered at z ~ 0.690. The Balmer line peaks are 4100 km s–1 bluer than the systemic redshift. There are no previously known objects with such an extreme difference between broad Mg II and broad Balmer emission. The two most promising explanations are either an extreme disk emitter or a high-velocity black hole recoil. However, neither explanation appears able to explain all of the observed features of SDSS 0956+5128, so the object may provide a challenge to our general understanding of quasar physics.Keywords
This publication has 68 references indexed in Scilit:
- A CANDIDATE DUAL ACTIVE GALACTIC NUCLEUS ATz= 1.175The Astrophysical Journal, 2011
- THE EIGHTH DATA RELEASE OF THE SLOAN DIGITAL SKY SURVEY: FIRST DATA FROM SDSS-IIIThe Astrophysical Journal Supplement Series, 2011
- THE RADIUS-LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI: THE EFFECT OF HOST-GALAXY STARLIGHT ON LUMINOSITY MEASUREMENTS. II. THE FULL SAMPLE OF REVERBERATION-MAPPED AGNsThe Astrophysical Journal, 2009
- A candidate sub-parsec supermassive binary black hole systemNature, 2009
- Chandraunveils a binary active galactic nucleus in Mrk 463Monthly Notices of the Royal Astronomical Society, 2008
- Recoiling Black Holes in QuasarsThe Astrophysical Journal, 2007
- Maximum Gravitational RecoilPhysical Review Letters, 2007
- The Third Data Release of the Sloan Digital Sky SurveyThe Astronomical Journal, 2005
- Arp 299: A Second Merging System with Two Active Nuclei?The Astrophysical Journal, 2004
- Structure of line-emitting accretion disks in active galactic nuclei - ARP 102BThe Astrophysical Journal, 1989