arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1101.2289astro-ph.HE
收藏

外能隙模型中的AXP和SGR:面对费米观测

AXPs and SGRs in the outer gap model: confronting Fermi observations

H. Tong, L. M. Song, R. X. Xu

摘要:

异常X射线源(AXP)和软伽马射线中继器(SGR)是磁星候选者,即,由强磁场提供能量的中子星。如果它们确实是磁星,它们将发射高能伽马射线,根据外隙模型,费米-LAT可以探测到。然而,没有显着的检测报告,在最近的费米-LAT观测所有已知的AXP和SGRs。考虑到理论与观测之间的差异,我们计算了所有AXP和SGR的理论谱,并给出了足够的观测参数。我们的结果表明,大多数AXP和SGR是高能γ射线发射体,如果他们真的是磁星。Fermi-LAT应检测到4个AXP 1 E 1547.0-5408、XTE J1810-197、1 E 1048.1-5937和4U 0142+61。在磁星的情况下,外能隙模型与费米观测之间存在矛盾。在磁星模型的可能解释进行了讨论。另一方面,如果AXP和SGR是回退磁盘系统,即,由于这些持续性辐射是由吸积提供动力的,因此它们中的大多数不是高能伽马射线发射体。未来对AXP和SGR的深Fermi-LAT观测将帮助我们弄清楚它们是磁星还是后备磁盘系统。

英文摘要:

Anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) are magnetar candidates, i.e., neutron stars powered by strong magnetic field. If they are indeed magnetars, they will emit high-energy gamma-rays which are detectable by Fermi-LAT according to the outer gap model. However, no significant detection is reported in recent Fermi-LAT observations of all known AXPs and SGRs. Considering the discrepancy between theory and observations, we calculate the theoretical spectra for all AXPs and SGRs with sufficient observational parameters. Our results show that most AXPs and SGRs are high-energy gamma-ray emitters if they are really magnetars. The four AXPs 1E 1547.0-5408, XTE J1810-197, 1E 1048.1-5937, and 4U 0142+61 should have been detected by Fermi-LAT. Then there is conflict between out gap model in the case of magnetars and Fermi observations. Possible explanations in the magnetar model are discussed. On the other hand, if AXPs and SGRs are fallback disk systems, i.e., accretion-powered for the persistent emissions, most of them are not high-energy gamma-ray emitters. Future deep Fermi-LAT observations of AXPs and SGRs will help us make clear whether they are magnetars or fallback disk systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑