Title: Flux Relaxation after two outbursts of the magnetar SGR 1627$-$41 and possible hard X-ray emission Show Chinese title

Title: 磁星 SGR 1627 两次爆发后的通量弛豫$-$41 以及可能的硬 X 射线发射

Abstract: We report on the long-term flux relaxation of the magnetar SGR 1627-41 after its 2008 outburst, and evidence for hard X-ray excess measured with NuSTAR. We use new observations made with Chandra and XMM-Newton, and an archival NuSTAR observation which add flux measurements at ~2000 days into quiescence after the 2008 outburst. We find that the source flux has further declined since the last measurement made in 2011, ~1000 days after the outburst in 2008. This trend is similar to the relaxation after the source's 1998 outburst. We use crustal cooling models to reproduce the flux relaxation; if the whole surface of the star is heated in the outbursts, the modeling suggests that the 2008 outburst of SGR 1627-41 deposited energy into the inner crust and that the core temperature of SGR 1627-41 is low (T_c<10^8 K) as previously suggested. On the other hand, if only a small fraction of the surface is heated or the temperature in the crust reached the melting temperature, relaxation at early times requires another emission mechanism. Finally, we report on evidence for hard X-ray emission in SGR 1627-41 which follows the observational correlation suggested by Kaspi & Boydstun (2010) in magnetars. Show Chinese abstract

Abstract: 我们报告了磁星SGR 1627-41在2008年爆发后长期通量弛豫的情况，并使用NuSTAR测量到硬X射线过量的证据。 我们利用了钱德拉和XMM-Newton的新观测数据，以及档案中的NuSTAR观测数据，在2008年爆发后的约2000天进入平静期时增加了通量测量值。 我们发现，自2011年最后一次测量以来（即2008年爆发后的约1000天），源的通量进一步下降。 这一趋势与源1998年爆发后的弛豫过程类似。 我们使用地壳冷却模型来重现通量弛豫；如果恒星表面在爆发期间被完全加热，则建模表明SGR 1627-41的2008年爆发向内地壳注入了能量，并且SGR 1627-41的核心温度较低（T_c<10^8 K），如先前所建议。 另一方面，如果仅有一小部分表面被加热或者地壳温度达到了熔点，则早期的弛豫需要另一种发射机制。 最后，我们报告了SGR 1627-41中硬X射线发射的证据，该证据遵循Kaspi和Boydstun（2010）在磁星中提出的观测相关性。