Recoiling Supermassive Black Holes: a search in the Nearby Universe

Abstract

The coalescence of a binary black hole can be accompanied by a large gravitational recoil due to anisotropic emission of gravitational waves. A recoiling supermassive black hole (SBH) can subsequently undergo long-lived oscillations in the potential well of its host galaxy, suggesting that offset SBHs may be common in the cores of massive ellipticals. We have analyzed HST archival images of 14 nearby core ellipticals, finding evidence for small ($\lesssim 10$ pc) displacements between the AGN (locating the SBH) and the center of the galaxy (the mean photocenter) in 10 of them. Excluding objects that may be affected by large-scale isophotal asymmetries, we consider six galaxies to have detected displacements, including M87, where a displacement was previously reported by Batcheldor et al. 2010. In individual objects, these displacements can be attributed to residual gravitational recoil oscillations following a major or minor merger within the last few Gyr. For plausible merger rates, however, there is a high probability of larger displacements than those observed, if SBH coalescence took place in these galaxies. Remarkably, the AGN-photocenter displacements are approximately aligned with the radio source axis in four of the six galaxies with displacements, including three of the four having relatively powerful kpc-scale jets. This suggests intrinsic asymmetries in radio jet power as a possible displacement mechanism, although approximate alignments are also expected for gravitational recoil. Orbital motion in SBH binaries and interactions with massive perturbers can produce the observed displacement amplitudes but do not offer a ready explanation for the alignments.

58 pages, 32 figures, 9 tables. Accepted for publication in ApJ

References in corpus (16)

• The SAURON project -- X. The orbital anisotropy of elliptical and lenticular galaxies: revisiting the (V/sigma,epsilon) diagram with integral-field stellar kinematics
• Large Merger Recoils and Spin Flips From Generic Black-Hole Binaries
• Massive black hole binary mergers within sub-pc scale gas discs
• Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas
• Ejection of Supermassive Black Holes from Galaxy Cores
• The Structures of Distant Galaxies - III: The Merger History of over 20,000 Massive Galaxies at z < 1.2
• The accretion mechanism in low-power radio galaxies
• Physical Properties of Very Powerful FRII Radio Galaxies
• A Displaced Supermassive Black Hole in M87
• EM counterparts of recoiling black holes: general relativistic simulations of non-Keplerian discs
• The host galaxy/AGN connection in nearby early-type galaxies. A new view of the origin of the radio-quiet/radio-loud dichotomy?
• Optical IFU Observations of the Brightest Cluster Galaxy NGC 4696: The Case for a Minor Merger and Shock-excited Filaments
• The Black Hole Mass and Extreme Orbital Structure in NGC1399
• Dynamics of Kicked and Accelerated Massive Black Holes in Galaxies
• On the nature of optical nuclei in FR I radio-galaxies from ACS/HST imaging polarimetry
• Small Scale Systems of Galaxies. III. X-ray detected E+S galaxy pairs in low density environments

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