Saxton, RD and Read, AM and Komossa, S and Rodriguez-Pascual, P and Miniutti, G and Dobbie, P and Esquej, P and Colless, M and Bannister, KW, An X-ray and UV flare from the galaxy XMMSL1 J061927.1-655311, Astronomy and Astrophysics, 572 Article A1. ISSN 0004-6361 (2014) [Refereed Article]
Copyright 2014 Astronomy & Astrophysics
Aims: New high variability extragalactic sources may be identified by comparing the flux of sources seen in the XMM-Newton Slew Survey with detections and upper limits from the ROSAT All Sky Survey.
Methods: A detected flaring extragalactic source was monitored with Swift and XMM-Newton to track its temporal and spectral evolution. Optical and radio observations were made to help classify the galaxy, investigate the reaction of circumnuclear material to the X-ray flare, and check for the presence of a jet.
Results: In November 2012, X-ray emission was detected from the galaxy XMMSL1 J061927.1-655311 (a.k.a. 2MASX 06192755-6553079), a factor 140 times higher than an upper limit from 20 years earlier. Both the X-ray and UV flux subsequently fell over the following year by factors of 20 and 4, respectively. Optically, the galaxy appears to be a Seyfert I with broad Balmer lines and weak, narrow, low-ionisation emission lines, at a redshift of 0.0729. The X-ray luminosity peaks at LX ~ 8 × 1043 erg s-1 with a typical Sy I-like power-law X-ray spectrum of Γ ~ 2. The flare has either been caused by a tidal disruption event or by an increase in the accretion rate of a persistent active galactic nucleus.
|Item Type:||Refereed Article|
|Keywords:||galaxies: active, galaxies: individual: XMMSL1 J061927.1-655311, X-rays: galaxies|
|Research Division:||Physical Sciences|
|Research Group:||Astronomical and Space Sciences|
|Research Field:||Cosmology and Extragalactic Astronomy|
|Objective Division:||Expanding Knowledge|
|Objective Group:||Expanding Knowledge|
|Objective Field:||Expanding Knowledge in the Physical Sciences|
|UTAS Author:||Dobbie, P (Dr Paul Dobbie)|
|Web of Science® Times Cited:||8|
|Deposited By:||Mathematics and Physics|
|Downloads:||431 View Download Statistics|
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