A broad spectral feature detected during the cooling phase of a type I X-ray burst from GRS 1747-312 with Suzaku
A broad spectral feature detected during the cooling phase of a type I X-ray burst from GRS 1747-312 with Suzaku
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DOI：
10.1093/pasj/psx037
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发表时间：
2017-08
影响因子：
2.3
通讯作者：
M. Iwai;T. Dotani;T. Dotani;M. Ozaki;Y. Maeda;H. Mori;S. Saji
中科院分区：
文献类型：
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作者：
M. Iwai;T. Dotani;T. Dotani;M. Ozaki;Y. Maeda;H. Mori;S. Saji
我们分析了 GRS 1747−312（位于球状星团 Terzan 6 中的低质量 X 射线双星）的 I 型 X 射线爆发的朱雀档案数据。在用覆盖 Terzan 6 的朱雀进行银河核球测绘观测期间，偶然发现了持续时间长且光球半径适度扩张的 X 射线爆发，并被认为最有可能源自于GRS 1747−312。在大部分时间里，时分突发光谱都可以用吸收黑体很好地再现，但在冷却阶段后期检测到显着偏差。这种偏差是由于在~7 keV以上的能谱中在爆发的冷却阶段逐渐发展的滚降特征造成的。我们测试了各种模型来重现光谱特征，发现三种类型的模型（冷物质反射、部分覆盖吸收和中子星快速旋转导致的多普勒模糊吸收边缘）给出了统计上可接受的拟合。我们讨论了这些模型的可行性，包括突发光谱的非普朗克性质。
We analyzed the Suzaku archive data of a type I X-ray burst from GRS 1747−312, a low-mass X-ray binary located in the globular cluster Terzan 6. During the Galactic bulge mapping observations with Suzaku, which covered Terzan 6, an X-ray burst of long duration and with moderate photospheric-radius expansion was serendipitously detected and was considered to be most probably originating from GRS 1747−312. The time-divided burst spectra were reproduced well with an absorbed blackbody over the majority of the time, but significant deviation was detected late in the cooling phase. The deviation was due to a rolled-off feature, which gradually developed in the cooling phase of the burst, in the energy spectra above ∼7 keV. We tested various models to reproduce the spectral feature and found three types of models (reflection by cold matter, partial-covering absorption, and Doppler-smeared absorption edges due to the rapid spin of a neutron star) gave a statistically acceptable fit. We discussed the feasibility of these models, including a non-Planckian nature of the burst spectra.