Chandra Constraints on the Column Density to XTE J1817-330
ATel #746; J. M. Miller (Michigan), J. Homan (MIT), D. Steeghs (CfA), R. Wijnands (Amsterdam)
on 23 Feb 2006; 17:01 UT
Credential Certification: Jon Miller (jonmm@umich.edu)
Subjects: X-ray, Binary, Black Hole, Transient
Referred to by ATel #: 749
We observed the black hole candidate with Chandra for 50 ksec, starting on Feb 13 2006 at 02:04 UT. The HETGS was used to obtain a high resolution spectrum, which was read-out with the ACIS-S array.
Initial fits to the spectra have been made using XSPEC and ISIS.
For a number of continuum models, and neutral absorption models, we find N_H = 8.8-9.7 E+20 cm^-2.
This value is even lower than that anticipated in ATEL 743.
The continuum spectrum is dominated by a kT = 0.93 keV disk, throughout the 0.5-10.0 keV band.
Our results indicate that the column density along the line of sight to XTE J1817-330 is lower than all strong black hole candidates, apart from XTE J1118+480. We strongly urge efforts to coordinate fast X-ray and optical photometry to search for simultaneous QPOs.
