[ Previous | Next | ADS ]

IGR J00291+5934: an observation with Chandra

ATel #369; M. A. Nowak (MIT-CXC), A. Paizis (ISDC Geneva / IASF Milano), J. Wilms (Department of Physics, University of Warwick), K. Ebisawa (NASA - GSFC / ISDC Geneva), T. J.-L. Courvoisier (ISDC Geneva), J. Rodriguez (CEA Saclay / ISDC Geneva), R. Walter (ISDC Geneva), M. Del Santo (IASF Roma), P. Ubertini (IASF Roma)
on 17 Dec 2004; 16:30 UT
Credential Certification: Jerome Rodriguez (jrodriguez@cea.fr)

Subjects: Radio, Infra-Red, Optical, X-ray, Binary, Neutron Star, Transient, Pulsar

Referred to by ATel #: 1660

We have performed a preliminary analysis of a Chandra observation of IGR J00291+5934 that lasted 18 ksec, from 2004-12-14T02:43:41 to 2004-12-14T08:02:38 (UT time).

The X-ray position, from the zeroth order image from ACIS-S/HETG, is consistent with previously reported optical (Fox and Kulkarni 2004 ATEL #354) and radio (Rupen et al. 2004 ATEL #364) positions to within 0.5". The X-ray position is: RA 00:29:03.08, Dec +59:34:19.2 (J2000)

The continuum is well-fitted by an absorbed power law with Nh = (2.8 +/- 0.4) * 1021 cm-2 and photon index Gamma = 1.9 +/- 0.1 (90% confidence level).

The absorbed flux is: 2 * 10-11 erg/cm-2/sec in 0.5-8 keV, and 1.4 * 10-11 erg/cm-2/sec in 2-8 keV. This value (about 1 mCrab) confirms the steady decline of the source (29 mCrab, 2-10 keV, on Dec 3 and less than 10 mCrab on Dec 11, Swank and Markwardt 2004 ATEL #365).

There is a hint of an iron emission line. No evidence for variations on the orbital period was seen. More details will be given in a forthcoming paper.