Journal article · Preprint article
A NuSTAR observation of the reflection spectrum of the low-mass X-ray binary 4U 1728-34
University of California at Berkeley1
NASA Goddard Space Flight Center2
Stanford University3
University of Michigan, Ann Arbor4
Université Fédérale Toulouse Midi-Pyrénées5
National Space Institute, Technical University of Denmark6
Astrophysics and Atmospheric Physics, National Space Institute, Technical University of Denmark7
Columbia University8
California Institute of Technology9
Harvard University10
...and 0 moreWe report on a simultaneous NuSTAR and Swift observation of the neutron star low-mass X-ray binary 4U 1728-34. We identified and removed four Type I X-ray bursts during the observation in order to study the persistent emission. The continuum spectrum is hard and described well by a blackbody with kT = 1.5 keV and a cutoff power law with Γ = 1.5, and a cutoff temperature of 25 keV.
Residuals between 6 and 8 keV provide strong evidence of a broad Fe Kα line. By modeling the spectrum with a relativistically blurred reflection model, we find an upper limit for the inner disk radius of Rin≤2RISCO. Consequently, we find that RNS ≤ 23 km, assuming M = 1.4 M ⊙ and a = 0.15. We also find an upper limit on the magnetic field of B ≤ 2 × 108 G.
| Language: | English |
|---|---|
| Publisher: | American Astronomical Society |
| Year: | 2016 |
| Pages: | 134 |
| ISSN: | 15384357 and 0004637x |
| Types: | Journal article and Preprint article |
| DOI: | 10.3847/0004-637X/827/2/134 |
| ORCIDs: | 0000-0001-5506-9855 , 0000-0002-4576-9337 , 0000-0002-0393-9190 , Christensen, Finn Erland , 0000-0001-7655-4120 , 0000-0003-2686-9241 , 0000-0001-5819-3552 and Chenevez, Jérôme |
