Unusual Double-peaked Emission in the SDSS Quasar J093201.60+031858.7

Abstract: We examine spectral properties of the SDSS quasar J093201.60+031858.7, in particular the presence of strong blue peaks in the Balmer emission lines offset from the narrow lines by approximately 4200 km/s. Asymmetry in the broad central component of the Hbeta line indicates the presence of a double-peaked emitter. However, the strength and sharpness of the blue Hbeta and blue Hgamma peaks make this quasar spectrum unique amongst double-peaked emitters identified from SDSS spectra. We fit a disk model to the Hbeta line and compare this object with other unusual double-peaked quasar spectra, particularly candidate binary supermassive black holes (SMBHs). Under the binary SMBH scenario, we test the applicability of a model in which a second SMBH may produce the strong blue peak in the Balmer lines of a double-peaked emitter. If there were only one SMBH, a circular, Keplerian disk model fit would be insufficient, indicating some sort of asymmetry is required to produce the strength of the blue peak. In either case, understanding the nature of the complex line emission in this object will aid in further discrimination between a single SMBH with a complex accretion disk and the actual case of a binary SMBH.