Volume 622, February 2019
|Number of page(s)||5|
|Section||Letters to the Editor|
|Published online||24 January 2019|
Letter to the Editor
Discovery and follow-up of the unusual nuclear transient OGLE17aaj
Warsaw University Astronomical Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland
2 European Southern Observatory, Karl Schwarzschild Str 2, 85748 Garching, Germany
3 IAASARS, National Observatory of Athens, Vas. Pavlou & I. Metaxa, Penteli 15236, Greece
4 Sternberg Astronomical Institute, Moscow State University, Universitetsky pr. 13, Moscow 119991, Russia
5 Lebedev Physical Institute, Astro Space Center, Profsoyuznaya 84/32, Moscow 117997, Russia
6 School of Physics, O’Brien Centre for Science North, University College Dublin, Belfield Dublin 4, Ireland
7 Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138, USA
8 Department of Physics, University of California, Santa Barbara, CA 93106-9530, USA
9 Las Cumbres Observatory, 6740 Cortona Dr Ste 102, Goleta, CA 93117-5575, USA
10 The Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel
11 Department of Physics, ETH Zurich, Wolgang-Pauli-Str. 27, Zurich 8093, Switzerland
12 SRON, Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
13 Department of Astrophysics/IMAPP, Radboud University, PO Box 9010, 6500 GL Nijmegen, The Netherlands
14 Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Väisäläntie 20, 21500 Piikkiaö, Finland
15 Ohio State University, Department of Astronomy, 140 West 18th Avenue, Columbus, OH 43210, USA
16 Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
17 Department of Astronomy, The Oskar Klein Center, Stockholm University, AlbaNova 10691, Stockholm, Sweden
18 Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, UK
19 School of Physics & Astronomy, University of Southampton, Southampton SO17 1BJ, UK
20 Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 234 Herzl St., Rehovot, Israel
21 Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstr. 1, 85748 Garching, Germany
22 South African Astronomical Observatory, PO Box 9, Observatory 7935, South Africa
Accepted: 4 January 2019
Aims. 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).
Methods. 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.
Results. 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.
Key words: black hole physics / Galaxy: nucleus
© ESO 2019
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.