A Dependence of the Tidal Disruption Event Rate on Global Stellar Surface Mass Density and Stellar Velocity Dispersion
French, K. Decker
Zahid, H. Jabran
Mandel, Kaisey S.
AffiliationUniv Arizona, Steward Observ
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationA Dependence of the Tidal Disruption Event Rate on Global Stellar Surface Mass Density and Stellar Velocity Dispersion 2018, 853 (1):39 The Astrophysical Journal
JournalThe Astrophysical Journal
Rights© 2018. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractThe rate of tidal disruption events (TDEs), R-TDE, is predicted to depend on stellar conditions near the super-massive black hole (SMBH), which are on difficult-to-measure sub-parsec scales. We test whether R-TDE depends on kpc-scale global galaxy properties, which are observable. We concentrate on stellar surface mass density, Sigma M-*, and velocity dispersion, sigma(nu), which correlate with the stellar density and velocity dispersion of the stars around the SMBH. We consider 35 TDE candidates, with and without known X-ray emission. The hosts range from star-forming to quiescent to quiescent with strong Balmer absorption lines. The last (often with post-starburst spectra) are overrepresented in our sample by a factor of 35(-17)(+21) or 18(-7)(+8), depending on the strength of the H delta absorption line. For a subsample of hosts with homogeneous measurements, Sigma M-* = 10(9)-10(10) M-circle dot/kpc(2), higher on average than for a volume-weighted control sample of Sloan Digital Sky Survey galaxies with similar redshifts and stellar masses. This is because (1) most of the TDE hosts here are quiescent galaxies, which tend to have higher Sigma M-* than the star-forming galaxies that dominate the control, and (2) the star-forming hosts have higher average Sigma M-* than the star-forming control. There is also a weak suggestion that TDE hosts have lower sigma(nu) than for the quiescent control. Assuming that R-TDE infinity Sigma M-*(alpha) x sigma(beta)(nu), and applying a statistical model to the TDE hosts and control sample, we estimate (alpha) over cap = 0.9 +/- 0.2 and (beta) over cap = -1.0 +/- 0.6. This is broadly consistent with RTDE being tied to the dynamical relaxation of stars surrounding the SMBH.
VersionFinal published version
SponsorsNSF [AST-1602595, AST-1211196, AST-1516854, AST-0908280]; NASA through Space Telescope Science Institute [HST-HF2-51391.001-A]; NASA [NAS5-26555, ADP-NNX10AE88G]; NASA; Open TDE Catalog; Alfred P. Sloan Foundation; National Science Foundation; U.S. Department of Energy; National Aeronautics and Space Administration; Japanese Monbukagakusho; Max Planck Society; Higher Education Funding Council for England; U.S. Department of Energy Office of Science