Understanding the X-ray spectrum of anomalous X-ray pulsars and soft gamma-ray repeaters  

作　　者：Yan-Jun Guo Shi Dai Zhao-Sheng Li Yuan Liu Hao Tong Ren-Xin Xu 

机构地区：[1]School of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University [2]Institute of High Energy Physics,Chinese Academy of Sciences [3]Xinjiang Astronomical Observatory,Chinese Academy of Sciences [4]Kavli Institute for Astronomy and Astrophysics,Peking University

出　　处：《Research in Astronomy and Astrophysics》2015年第4期525-536,共12页天文和天体物理学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China

摘　　要：Hard X-rays above 10 keV are detected from several anomalous X-ray pul- sars （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 J 170849-400910, 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 Triimper 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.Hard X-rays above 10 keV are detected from several anomalous X-ray pul- sars （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 J 170849-400910, 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 Triimper 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.

关 键 词：stars： neutron -- pulsars： individual （1E 1547.0-5408 1RXS J170849-400910 SGR 0501＋4516 SGR 1806-20） - X-rays： stars 

分 类 号：P172[天文地球—天文学] P145.6