Discovery and Follow-up of the Unusual Nuclear Transient OGLE17aaj [HEAP]

http://arxiv.org/abs/1901.03718


We report on the discovery and follow-up of a peculiar transient, OGLE17aaj, which occurred in the nucleus of a weakly active galaxy. We investigate whether it can be interpreted as a new candidate for a tidal disruption event (TDE). We present the OGLE-IV light curve that covers the slow 60-day-long rise to maximum along with photometric, spectroscopic, and X-ray follow-up during the first year. OGLE17aaj is a nuclear transient exhibiting some properties similar to previously found TDEs, including a long rise time, lack of colour-temperature evolution, and high black-body temperature. On the other hand, its narrow emission lines and slow post-peak evolution are different from previously observed TDEs. Its spectrum and light-curve evolution is similar to F01004-2237 and AT 2017bgt. Signatures of historical low-level nuclear variability suggest that OGLE17aaj may instead be related to a new type of accretion event in active super-massive black holes.

Read this paper on arXiv…

M. Gromadzki, A. Hamanowicz, L. Wyrzykowski, et. al.
Tue, 15 Jan 19
49/83

Comments: 5 pages, 3 figures, accepted for publication in Astronomy & Astrophysics as Letter to Editor