Swift/BAT detects increased hard X-ray activity from GX 304-1
ATel #2538; H. A. Krimm (CRESST/GSFC/USRA), S. D. Barthelmy (GSFC), W. Baumgartner (CRESST/GSFC/UMBC), J. Cummings (CRESST/GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), C. B. Markwardt (CRESST/GSFC/UMD), D. Palmer (LANL), T. Sakamoto (CRESTT/GSFC/UMBC), G. Skinner (CRESST/GSFC/UMD), M. Stamatikos (OSU/GSFC), J. Tueller (GSFC), T. Ukwatta (GSFC/GWU)
on 6 Apr 2010; 22:07 UT
Credential Certification: Hans A. Krimm (Hans.Krimm@nasa.gov)
Subjects: X-ray, Binary, Neutron Star, Transient, Pulsar
The Swift/BAT hard X-ray transient monitor reports increased activity in the
15-50 keV band for the transient pulsar and Be/X-ray binary and HMXB GX 304-1.
Starting on 21-Mar-2010 (MJD 55276), the source has increased in intensity from
an undetectable level (one-sigma upper limit of 0.002 cts/cm2/sec or 8 mcrab) up
to a current level of 0.036 ± 0.002 cts/cm2/sec (160 mcrab) on 05-Apr-2010. This
is the highest rate seen in the BAT monitor since the peak two days of its
outburst in Nov-2009 (Yamamoto et al, ATel #2297) and the longest sustained outburst seen from
this source since the start of the Swift mission in Nov-2004.
Examination of the light curve on the RXTE All-Sky Monitor web page shows that
this recent outburst is also observed at lower X-ray energies.
Swift/BAT Hard X-ray Transient light curve for GX 304-1
