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ATEL # 995; V. Mangano (INAF-IASF Palermo), P. Romano (INAF-OABrera), L. Sidoli (INAF-IASF Milano)
on 9 Feb 2007; 11:22 UT
Distributed as an Instant Email Notice (Request for Observations)
Password Certification: Vanessa Mangano (firstname.lastname@example.org)
Subjects: X-ray, Request for Observations, Binaries, Transients
Referred to by ATEL #: 996, 997
IGR J11215-5952 is undergoing a new periodic outburst as observed with Swift/XRT (Romano et al. ATel #994, where the early phase of the outburst has been reported).
During subsequent observations with Swift/XRT, IGRJ11215-5952 has been observed to undergo a bright flare, starting on 9 February (01:30 UT) and reaching about 2E-10 erg/cm2/s in the energy range 1-10 keV (see below for the lightcurve of the bright flare), 329 days from the last outburst in March 2006 (Sidoli et al. 2006,A&A,450,L9; Smith et al.2006,ATEL #766).
The spectrum can be fit with a single power-law with a photon index of 0.93-0.20+0.24, absorbed with a column density of (1.02-0.30+0.42)E22 cm^-2. The source flux 1.6E-10 erg/cm2/s translates into a 1-10 keV luminosity of 7E+35 erg/s at 6.2 kpc.
We will follow the evolution of the outburst in the next days (typical outburst duration is limited to 2-3 days).
We would like to thank the Swift Team for making these observations possible, in particular N. Gehrels and D. Burrows, the duty scientists as well as the science planners.