X-ray and UV observations of two radio-bright quasars
X-ray and UV observations of two radio-bright quasars
复制标题
两个射电亮类星体的 X 射线和紫外线观测
DOI：
10.1086/161970
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
G. Fabbiano
中科院分区：
文献类型：
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作者：
M. Elvis;G. Fabbiano
PKS 10004 + 13 （4C 13.41， V约等于15.2,z = 0.140）和PKS 0637 - 75 （V = 15.75, z = 0.651）两个类星体是在1980年12月用IUE观测到的。两者都在短波长区域被检测到。目前PKS 1004 + 13的x射线上限给出了在类星体中测量到的最低L-x/L-opt。PKS 0637 - 75几乎与爱因斯坦天文台同时观测到，并与IPC获得了光谱。紫外和软x射线数据结合在一起，并与两个物体的光学和红外数据一起讨论。PKS 1004 + 13的极端L-x/L-opt比值可能是一个特别大的黑体紫外线过量叠加在斜率约为1.1的幂律连续体上的结果。另一种选择是用一个大的氢柱吸收低能x射线，尽管这不太可能。PKS 0637 - 75没有显示任何紫外线过量的证据。这两个类星体似乎处于由黑体组成的紫外光谱占主导地位程度的两端。PKS 0637 - 75在一个介入星系的红移处缺乏莱曼极限不连续意味着光学检测到的介入氢是电离的。
The two quasars PKS 10004 + 13 (4C 13.41, V about equal to 15.2, z = 0.140) and PKS 0637 - 75 (V = 15.75, z = 0.651) were observed in December 1980 with IUE. Both were detected in the short-wavelength region. The present X-ray upper limit for PKS 1004 + 13 gives the lowest L-x/L-opt measured in quasars. PKS 0637 - 75 was observed nearly simultaneously with the Einstein Observatory and a spectrum obtained with the IPC. The UV and soft X-ray data have been combined and are discussed together with the optical and infrared data for both objects. The extreme L-x/L-opt ratio of PKS 1004 + 13 may be the result of an exceptionally large blackbody UV excess superposed on a power-law continuum of slope about 1.1. An alternative would be a large hydrogen column absorbing low-energy X-rays although this is unlikely. PKS 0637 - 75 shows no evidence for any UV excess. The two quasars seem to be at opposite ends of the degree of dominance of the UV spectrum by a blackbody component. The lack of a Lyman limit discontinuity in PKS 0637 - 75 at the redshift of an intervening galaxy implies that the optically detected, intervening hydrogen is ionized.