Chandra non-detection of the neutron star X-ray transient IGR J17191-2821
ATel #1096; Deepto Chakrabarty, Miriam I. Krauss (MIT); Peter G. Jonker (SRON/CfA); Adrienne M. Juett (U. Virginia); and Craig B. Markwardt (CRESST/U. Maryland/NASA/GSFC)
on 1 Jun 2007; 20:50 UT
Credential Certification: Miriam I. Krauss (firstname.lastname@example.org)
Subjects: X-ray, Binary, Neutron Star, Transient
Referred to by ATel #: 4170
We report on a Chandra/HRC-I observation of the neutron star transient IGR J17191-2821 which was recently in outburst, with activity beginning on April 29 and lasting approximately two weeks (ATels #1021, #1022, #1025, #1065, #1068, #1069, #1070, #1075). The 1.1 ks observation was performed starting May 27 (23:31 UTC). No sources are detected within 30 arcsec of the improved Swift/XRT position (4 arcsec accuracy; Atel #1070). We find a 90%-confidence upper limit on the source rate of <2.0E-3 counts/s. This corresponds to a 2-10 keV source flux of <6.9E-14 erg/cm^2/s (<3.2E-3 mCrab), assuming a power-law spectrum of index 1.71 and a neutral hydrogen column density of 5.7E21 cm^-2 (Atel #1070). Previously, a distance upper limit of 11 kpc was determined from a thermonuclear X-ray burst (Atel #1068). This implies that the 0.3-10 keV luminosity at the time of the Chandra observation was <1.2E33 ergs/s.