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An fe xxvi absorption line in the persistent spectrum of the dipping low mass x-ray binary 1a 1744-361
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Gavriil, Fotis P. Strohmayer, Tod E. Bhattacharyya, Sudip |
| Copyright Year | 2009 |
| Description | We report on Chandra X-ray Observatory (CXO) High-Energy Transmission Grating (HETG) spectra of the dipping Low Mass X-ray Binary (LMXB) 1A 1744-361 during its July 2008 outburst. We find that its persistent emission is well modeled by a blackbody (kT approx. 1.0 keV) plus power-law (Gamma approx. 1.7) with an absorption edge at 7.6 keV. In the residuals of the combined spectrum we find a significant absorption line at 6.961+/-0.002 keV, consistent with the Fe XXVI (hydrogen-like Fe) 2 - 1 transition. We place an upper limit on the velocity of a redshifted flow of v < 221 km/s. We find an equivalent width for the line of 27+2/-3 eV, from which we determine a column density of 7+/-1 x 10(exp 17)/sq cm via a curve-of-growth analysis. Using XSTAR simulations, we place a lower limit on the ionization parameter of > 10(exp 3.6) erg cm/s. The properties of this line are consistent with those observed in other dipping LMXBs. Using Rossi X-ray Timing Explorer (RXTE) data accumulated during this latest outburst we present an updated color-color diagram which clearly shows that IA 1744-361 is an "atoll" source. Finally, using additional dips found in the RXTE and CXO data we provide an updated orbital period estimate of 52+/-5 minutes. |
| File Size | 993361 |
| Page Count | 8 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20090038691 |
| Archival Resource Key | ark:/13960/t6741rj52 |
| Language | English |
| Publisher Date | 2009-01-01 |
| Access Restriction | Open |
| Subject Keyword | Astrophysics Deuterium Red Shift Simulation X Ray Binaries Ionization Flow Velocity Time Measurement X Ray Timing Explorer Line Spectra X Ray Astrophysics Facility Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
