We present a Chandra observation of SN 2016hnk, a candidate Ca-rich gap transient. This observation was specifically designed to test whether or not this transient was the result of the tidal detonation of a white dwarf by an intermediate-mass black hole. Since we detect no X-ray emission 28 days after the discovery of the transient, as predicted from fall-back accretion, we rule out this model. Our upper limit of ∼10 M⊙ does not allow us to rule out a neutron star or stellar-mass black hole detonator due limits on the sensitivity of Chandra to soft X-rays and unconstrained variables tied to the structure of super-Eddington accretion disks. Together with other Chandra and multiwavelength observations, our analysis strongly argues against the intermediate-mass black hole tidal detonation scenario for Ca-rich gap transients more generally.
@article{arxiv.1712.02799,
title = {Chandra X-ray Constraints on the Candidate Ca-rich Gap Transient SN 2016hnk},
author = {P. H. Sell and K. Arur and T. J. Maccarone and R. Kotak and C. Knigge and D. J. Sand and S. Valenti},
journal= {arXiv preprint arXiv:1712.02799},
year = {2018}
}