The Quasar SDSS J105041.35+345631.3: Black Hole Recoil or Extreme Double-Peaked Emitter?

• Published in: The Astrophysical journal Vol. 707; no. 2; pp. 936 - 941
• Main Authors: Shields, G. A, Rosario, D. J, Smith, K. L, Bonning, E. W, Salviander, S, Kalirai, J. S, Strickler, R, Ramirez-Ruiz, E, Dutton, A. A, Treu, T, Marshall, P. J
• Format: Journal Article
• Language: English
• Published: United States IOP Publishing 20-12-2009
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; COSMIC RADIO SOURCES; EMISSION; GALAXIES; QUASARS; RED SHIFT; SPECTRA
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/707/2/936

The quasar SDSS J105041.35+345631.3 (z = 0.272) has broad emission lines blueshifted by 3500 km s-1 relative to the narrow lines and the host galaxy. Such an object may be a candidate for a recoiling supermassive black hole, a binary black hole, a superposition of two objects, or an unusual geometry for the broad emission-line region. The absence of narrow lines at the broad line redshift argues against superposition. New Keck spectra of J1050+3456 place tight constraints on the binary model. The combination of large velocity shift and symmetrical H Delta *b profile, as well as aspects of the narrow line spectrum, make J1050+3456 an interesting candidate for black hole recoil. Other aspects of the spectrum, however, suggest that the object is most likely an extreme case of a 'double-peaked emitter.' We discuss possible observational tests to determine the true nature of this exceptional object.