XMMSL1 J162940.2-112024 : A new X-ray transient from the XMM-Newton Slew Survey
ATel #1689; A M Read (Leicester), R D Saxton (ESAC), P Esquej (MPE)
on 2 Sep 2008; 14:02 UT
Credential Certification: Dr. Andy Read (amr30@star.le.ac.uk)
Subjects: X-ray, Request for Observations, Transient
Referred to by ATel #: 1718
We report the discovery of XMMSL1 J162940.2-112024, a new X-ray
transient, found in an XMM-Newton slew from 20th August 2008. The
source position (2000.0) is RA:16 29 40.2 DEC:-11 20 24 with an 8'',
1 sigma error circle. No other XMM-Newton slew has covered this sky
position.
The source is bright and point-like. The (0.2-2 keV) count rate was 3.1
ct/s in the EPIC-pn detector, whilst the (0.2-10 keV) count rate was
4.9 ct/s. A power law fit to the rudimentary slew spectrum, using a
fixed Galactic absorption out of our galaxy at this position
(nH=1.4E21 cm-2), yields a spectral slope of 1.8. This gives rise to
an unabsorbed (0.2-2 keV) flux of 1.2E-11 erg/cm2/s, a factor 60
greater than the upper limit calculated from the ROSAT All Sky Survey
using the same spectral parameters.
Though the slew spectrum appears roughly similar to that of an AGN,
its position suggests that it may be a foreground object, such as a
flare star, CV or Nova. Two catalogued optical sources lie within the
error circle: USNO-B1.0*0786-0301344, R1=16.7, B1=19.5, and
USNO-B1.0*0786-0301348, R1=18.4, B1=19.7. We welcome further
observations to ascertain the true nature of the object.
