ASASSN-14ae: a tidal disruption event at 200 Mpc

December 2014 • 2014MNRAS.445.3263H

Authors • Holoien, T. W. -S. • Prieto, J. L. • Bersier, D. • Kochanek, C. S. • Stanek, K. Z. • Shappee, B. J. • Grupe, D. • Basu, U. • Beacom, J. F. • Brimacombe, J. • Brown, J. S. • Davis, A. B. • Jencson, J. • Pojmanski, G. • Szczygieł, D. M.

Abstract • ASASSN-14ae is a candidate tidal disruption event (TDE) found at the centre of SDSS J110840.11+340552.2 (d ≃ 200 Mpc) by the All-Sky Automated Survey for Supernovae (ASAS-SN). We present ground-based and Swift follow-up photometric and spectroscopic observations of the source, finding that the transient had a peak luminosity of L ≃ 8 × 10⁴³ erg s^-1 and a total integrated energy of E ≃ 1.7 × 10⁵⁰ erg radiated over the ∼5 months of observations presented. The blackbody temperature of the transient remains roughly constant at T ∼ 20 000 K while the luminosity declines by nearly 1.5 orders of magnitude during this time, a drop that is most consistent with an exponential, L ∝ e^{-t/t ₀} with t₀ ≃ 39 d. The source has broad Balmer lines in emission at all epochs as well as a broad He II feature emerging in later epochs. We compare the colour and spectral evolution to both supernovae and normal AGN to show that ASASSN-14ae does not resemble either type of object and conclude that a TDE is the most likely explanation for our observations. At z = 0.0436, ASASSN-14ae is the lowest-redshift TDE candidate discovered at optical/UV wavelengths to date, and we estimate that ASAS-SN may discover 0.1-3 of these events every year in the future.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2014MNRAS.445.3263H
• PREPRINT http://arxiv.org/abs/1405.1417
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2014MNRAS.445.3263H
• DATA http://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/biblink.pl?code=2014MNRAS.445.3263H
• DATA https://irsa.ipac.caltech.edu/bibdata/2014/H/2014MNRAS.445.3263H.html
• ELECTR https://doi.org/10.1093%2Fmnras%2Fstu1922