EXTRA-SOFT X-RAY EXCESS OF QUASARS

被引：0
|
作者：
周又元
晏明
程富华
苏暘
机构：
[1] China Center of Advanced Science and Technology (World Laboratory)
[2] Beijing and Center for Astrophysics
[3] University of Science and Technology of China
[4] Hefei
[5] PRC
[6] Center for Astrophysics
[7] Beijing
[8] and Center for Astrophysics
[9] Beijing Astronomical Observatory
来源：
Science in China,SerA. | 1990年 / Ser.A.1990卷 / 06期
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摘要：
<正> In a quasar sample with strong soft X-ray emission, we construct a sample of extra-soft X-ray excess quasars in virtue of the relation between the hydrogen column density, NH (IPC), determined by Einstein IPC, and NH (21cm), determined by Galactic 21cm line. The X-ray spectral index a*E in the energy interval 0.3keV<E<0.5keV is calculated. a*E is obviously larger than the spectral index αE in 0.5keV<E<3.5keV, showing that 0.3-0.5keV is just the rapidly decreasing part of the right side of big bump from UV to soft X-ray.These results will help establish the composite model for this kind of big bump.
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页码：720 / 728
页数：9
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