ASCA X-RAY OBSERVATIONS OF EX HYA : SPIN-RESOLVED SPECTROSCOPY
ASCA X-RAY OBSERVATIONS OF EX HYA : SPIN-RESOLVED SPECTROSCOPY
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ASCA 对 EX HYA 的 X 射线观测：自旋分辨光谱
DOI：
10.1046/j.1365-8711.1998.29511353.x
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发表时间：
1998
影响因子：
4.8
通讯作者：
A. Beardmore
中科院分区：
文献类型：
--
作者：
A. Allan;C. Hellier;A. Beardmore
A B STR A CT我们使用ASCA存档数据分析了中间极性EX Hya中自旋调制的光谱变化。我们发现这种调制可以用（1）白色矮星边缘对吸积极的遮蔽效应或（2）相位相关的光电吸收效应来模拟。我们认为，在偏X射线食的基础上，在系统中的吸积柱是高的，与冲击高度1Rwd，因此，自旋调制主要是由掩星引起的。我们发现，除了具有高Mwd的限制参数区域外，沿吸积激波沿着的温度分布与Aizu的计算不一致。因此，冲击波中的物质冷却的速度一定比理论预测的要快。
A B STR A CT We analyse the spectral changes over the spin modulation in the intermediate polar EX Hya using archival ASCA data. We find that the modulation can be modelled as either (1) the effect of occultation of the accretion poles by the limb of the white dwarf, or (2) the effect of phase-dependent photoelectric absorption. We argue, on the basis of the partial X-ray eclipse, that the accretion columns in the system are tall, with shock height 1R wd, and hence that the spin modulation is caused mainly by occultation. We find that the temperature distribution along the accretion shocks is incompatible with the calculations of Aizu, except for a restricted parameter regime with a high M wd. Hence the material in the shock must cool faster than predicted by theory.