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

TL;DR

This paper investigates the nature of quasar SDSS J105041.35+345631.3, which exhibits unusual spectral features, evaluating whether it is a recoiling black hole or an extreme double-peaked emitter through spectral analysis and observational constraints.

Contribution

The study provides new spectral data and analysis to distinguish between black hole recoil and double-peaked emission scenarios in this peculiar quasar.

Findings

Spectral features favor the double-peaked emitter interpretation.

Constraints from Keck spectra challenge the binary black hole hypothesis.

The object is likely an extreme case of a double-peaked emitter.

Abstract

The quasar SDSS J105041.35+345631.3 (z = 0.272) has broad emission lines blueshifted by 3500 km/s relative to the narrow lines and the host galaxy. Such an object may be a candidate for a recoiling supermassive black hole, 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+3546 place tight constraints on the binary model. The combination of large velocity shift and symmetrical H-beta profile, as well as aspects of the narrow line spectrum, make J1050+3546 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.