Revisiting Optical Tidal Disruption Events with iPTF16axa

Hung, T.
Gezari, S.
Blagorodnova, N.
Roth, N.
Cenko, S. B.
Kulkarni, S. R.
Horesh, A.
Arcavi, I.
McCully, C.
Yan, Lin
Lunnan, R.
Fremling, C.
Cao, Y.
Nugent, P. E.
Wozniak, P.

Publication date

June 2017

Publisher

American Astronomical Society

Abstract

We report the discovery by the intermediate Palomar Transient Factory (iPTF) of a candidate tidal disruption event (TDE) iPTF16axa at z = 0.108 and present its broadband photometric and spectroscopic evolution from three months of follow-up observations with ground-based telescopes and Swift. The light curve is well fitted with a t^(−5/3) decay, and we constrain the rise time to peak to be <49 rest-frame days after disruption, which is roughly consistent with the fallback timescale expected for the ~5 × 10^6 M_⊙ black hole inferred from the stellar velocity dispersion of the host galaxy. The UV and optical spectral energy distribution is well described by a constant blackbody temperature of T ~ 3 × 10^4 K over the monitoring period, with an...