Understanding the X-ray spectrum of anomalous X-ray pulsars and soft gamma-ray repeaters
Abstract
Hard X-rays above 10 keV are detected from several anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), and different models have been proposed to explain the physical origin within the frame of either a magnetar model or a fallback disk system. Using data from Suzaku and INTEGRAL, we study the soft and hard X-ray spectra of four AXPs/SGRs: 1RXS J170849-400910, 1E 1547.0-5408, SGR 1806-20 and SGR 0501+4516. It is found that the spectra could be well reproduced by the bulk-motion Comptonization (BMC) process as was first suggested by Trümper et al., showing that the accretion scenario could be compatible with X-ray emission from AXPs/SGRs. Simulated results from the Hard X-ray Modulation Telescope using the BMC model show that the spectra would have discrepancies from the power-law, especially the cutoff at ∼200 keV. Thus future observations will allow researchers to distinguish different models of the hard X-ray emission and will help us understand the nature of AXPs/SGRs.
Supported by the National Natural Science Foundation of China.- Publication:
-
Research in Astronomy and Astrophysics
- Pub Date:
- April 2015
- DOI:
- 10.1088/1674-4527/15/4/006
- arXiv:
- arXiv:1403.6739
- Bibcode:
- 2015RAA....15..525G
- Keywords:
-
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 12 pages, 6 figures, 6 tables, submitted to RAA