TY - JOUR
T1 - An X-ray and UV flare from the galaxy XMMSL1 J061927.1-655311
AU - Saxton, R. D.
AU - Read, A. M.
AU - Komossa, S.
AU - Rodriguez-Pascual, P.
AU - Miniutti, G.
AU - Dobbie, P.
AU - Esquej, P.
AU - Colless, M.
AU - Bannister, K. W.
N1 - Publisher Copyright:
© 2014 ESO.
PY - 2014/12/1
Y1 - 2014/12/1
N2 - 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.
AB - 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.
KW - Galaxies: active
KW - Galaxies: individual: XMMSL1 J061927.1-655311
KW - X-rays: galaxies
UR - http://www.scopus.com/inward/record.url?scp=84911457662&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201424347
DO - 10.1051/0004-6361/201424347
M3 - Article
SN - 0004-6361
VL - 572
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A1
ER -