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An fe xxiv 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 | 2012 |
| Description | We report on Chandra X-ray Observatory (Chandra) High Energy Transmission Grating spectra of the dipping low-mass X-ray binary 1A 1744â361 during its 2008 July 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. 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 nu < 221 km/s. We find an equivalent width for the line of 27+2/â3 eV, from which we determine a column density of (7 +/- 1)Ã10(exp 17) /sq. cm via a curve-of-growth analysis. Using XSTAR simulations, we place a lower limit on the ionization parameter of >103.6 erg cm/s. We discuss what implications the feature has on the system and its geometry. We also present Rossi X-ray Timing Explorer data accumulated during this latest outburst and, via an updated color-color diagram, clearly show that 1A 1744â361 is an "atoll" source |
| File Size | 593405 |
| Page Count | 9 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20140006006 |
| Archival Resource Key | ark:/13960/t9f52nx36 |
| Language | English |
| Publisher Date | 2012-07-01 |
| Access Restriction | Open |
| Subject Keyword | Stars Binaries Neutron Stellar Spectra Neutron Stars X Ray Binaries Spaceborne Astronomy Color-color Diagram X Ray Timing Explorer Line Spectra X Ray Astronomy 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 |
