Robinson, Andrew, Young, Stuart, Axon, David J, Kharb, Preeti and Smith, James E (2010) SPECTROPOLARIMETRIC EVIDENCE FOR A KICKED SUPERMASSIVE BLACK HOLE IN THE QUASAR E1821+643. Astrophysical Journal Letters, 717 (2). L122-L126. ISSN 2041-8205

PDF - Published Version
Download (344kB) | Preview


We report spectropolarimetric observations of the quasar E1821+643 ( z = 0.297), which suggest that it may be an example of gravitational recoil due to anisotropic emission of gravitational waves following the merger of a supermassive black hole (SMBH) binary. In total flux, the broad Balmer lines are redshifted by approximate to 1000 km s(-1) relative to the narrow lines and have highly red asymmetric profiles, whereas in polarized flux the broad Ha line exhibits a blueshift of similar magnitude and a strong blue asymmetry. We show that these observations are consistent with a scattering model in which the broad-line region has two components, moving with different bulk velocities away from the observer and toward a scattering region at rest in the host galaxy. If the high-velocity system is identified as gas bound to the SMBH, this implies that the SMBH is itself moving with a velocity similar to 2100 km s(-1) relative to the host galaxy. We discuss some implications of the recoil hypothesis and also briefly consider whether our observations can be explained in terms of scattering of broad-line emission originating from the active component of an SMBH binary, or from an outflowing wind.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Depositing User: David Axon
Date Deposited: 06 Feb 2012 19:15
Last Modified: 02 Jul 2019 20:48
URI: http://sro.sussex.ac.uk/id/eprint/19745

View download statistics for this item

📧 Request an update