Missing baryons and the soft X-ray background
Missing baryons and the soft X-ray background
复制标题
缺失重子和软 X 射线背景
DOI：
10.1051/0004-6361:20021291
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发表时间：
2002
影响因子：
6.5
通讯作者：
Mpe Garching
中科院分区：
文献类型：
--
作者：
A. Sołtan;M. Freyberg;G. Center;Warsaw;Mpe Garching
在三个 ROSAT 能量带中研究了舔计数星系和丰富星系团周围的 X 射线背景强度。研究发现，星系集中周围的 X 射线增强表现出比标准星团发射和平均河外背景明显更柔和的光谱。伴随星系的漫射软发射与 Cen 和 Ostriker 流体动力学模拟首先假设的热气体的热发射一致。我们对气体温度的估计——尽管存在很大的不确定性——在几个 Mpc 尺度上的平均温度低于 1 keV，这大大低于星团内气体的温度，但与当地星系间介质的预测温度一致。有人指出，计划中的 ROSITA 任务对于我们了解背景的扩散热成分至关重要。
The X-ray background intensity around Lick count galaxies and rich clusters of galaxies is investigated in three ROSAT energy bands. It is found that the X-ray enhancements surrounding concentrations of galaxies exhibit significantly softer spectrum than the standard cluster emission and the average extragalactic background. The diffuse soft emission accompanying the galaxies is consistent with the thermal emission of the hot gas postulated first by the Cen & Ostriker hydrodynamic simulations. Our estimates of the gas temperature – although subject to large uncertainties – averaged over several Mpc scales are below 1 keV, which is substantially below the temperature of the intra-cluster gas, but consistent with temperatures predicted for the local intergalactic medium. It is pointed out that the planned ROSITA mission would be essential for our understanding of the diffuse thermal component of the background.