'Re-outburst of M31 source XMMU J004215.8+411924'
ATel #2682; Nakisa Noorraee (DIAS, UCC), Robin Barnard (SAO), Wolfgang Pietsch (MPE), Paul Callanan (UCC) and Michael Garcia (SAO)
on 18 Jun 2010; 20:01 UT
Credential Certification: Michael R. Garcia (garcia@cfa.harvard.edu)
Subjects: X-ray, Binary, Neutron Star, Transient
From a 5ks Chandra ACIS-I observation of M31 on May 27 2010, we report
the re-outburst of XMMU J004215.8+411924. The first outburst was
discovered in August 2006, and also observed on 2006 July 31st and 2006
September 11 (Atels #881,899 and 969). The position as determined
from the May 27 2010 ACIS-I observation is within 0.5'' of that determined
from a July 31 2006 5ks ACIS-I observation and that determined by
Voss et al 2008 (A&A 489, 707).
The spectrum of new outburst can be fit with an absorbed powerlaw with
photon index of 1.7, and an absorption column density of
5.7x10^21 cm^-2. Spectral parameters are entirely consistent with those
found in ATEL 881. The 0.5-10 keV flux observed in the Chandra May 27
observation is 1.3x10^-12 erg cm-2, corresponding to an
emitted luminosity of 1.2x10^38 erg/s assuming a 780
kpc distance to M31. Swift observations on 2010 June 6, 9, 12, 15, and 18
find the source fading with an XRT count rate
of 0.011 c/s, 0.0088 c/s, 0.0061 c/s, 0.0054 c/s, and 0.0019 c/s.
Assuming the same spectral parameters as found with the ACIS-I observation,
and correcting for vingnetting dependent area, these XRT rates
correspond to emitted luminosities of
9.8, 7.5, 5.9, 4.4, and 1.3 in units of 10^37 ergs/sec.
Errors in the luminosities due to counting statistics
are 10% to 20%.
We thank the Swift team for carrying out these Target of Opportunity observations.
