posted on 2018-04-05, 10:44authored byG. C. Brown, A. J. Levan, E. R. Stanway, T. Krühler, N. R. Tanvir, L. J. M. Davies, A. Fruchter, S. B. Cenko, B. D. Metzger
We present late-time follow-up of the relativistic tidal disruption flare (rTDF) candidate Swift J1112.2−8238. We confirm the previously determined redshift of z = 0.8900 ± 0.0005 based on multiple emission line detections. Hubble Space Telescope imaging of the host galaxy indicates a complex and distorted morphology with at least two spatially distinct components. These are offset in velocity space by less than 350 km s−1 in VLT/X-Shooter observations, suggesting that the host is undergoing interaction with another galaxy. The transient position is consistent to 2.2σ with the centre of a bulge-like component at a distance of 1.1 ± 0.5 kpc from its centre. Luminous, likely variable radio emission has also been observed, strengthening the similarities between Swift J1112.2−8238 and other previously identified rTDFs. While the transient location is ∼ 2σ from the host centroid, the disrupted nature of the host may provide an explanation for this. The tidal disruption model remains a good description for these events.
Funding
GCB thanks the Midlands Physics Alliance for a PhD studentship and the Institute of Advanced Study, Warwick, for postdoctoral research funding. AJL and ERS acknowledge funding from the UK Science and Technology Facilities Council (STFC) associated with grant number ST/L000733/1. TK acknowledges support through the Sofja Kovalevskaja Award to PS from the Alexander von Humboldt Foundation of Germany. We also acknowledge travel funding from the STFC grant ST/M006492/1, and Royal Astronomical Society travel support. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 094.B-0703. Based on observations made with the NASA/ESA HST, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 13869. The ATCA is part of the Australia Telescope National Facility which is funded by the Australian government for operation as a national facility managed by CSIRO. The authors made use of the York Extinction Solver (YES, McCall 2004). The authors made use of Ned Wright's Javascript Cosmology Calculator (Wright 2006).
History
Citation
Monthly Notices of the Royal Astronomical Society, 2017, 472(4), pp. 4469–4479.
Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy
Version
VoR (Version of Record)
Published in
Monthly Notices of the Royal Astronomical Society
Publisher
Oxford University Press (OUP), Royal Astronomical Society