Observing H2 Emission in Forming Galaxies
Observing H2 Emission in Forming Galaxies
复制标题
观测星系形成过程中的 H2 发射
DOI：
10.1086/379282
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
T. Kitayama
中科院分区：
文献类型：
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作者：
K. Omukai;T. Kitayama
利用未来的单孔径远红外天文台（SAFIR）研究了形成中星系的H2冷却辐射，并讨论了它们的可观测性。质量为<$1011 M的星系在形成过程中释放出大部分的引力能量，这些能量是通过收缩释放出的氢分子线辐射，尽管在维里化过程中有很大一部分的热能被氢分子的Lyα辐射带走。对于质量更大的天体，由于动能耗散而产生的加热程度是如此之大，以至于温度不会下降到104 K以下，并且引力能主要通过Lyα发射而发射。因此，H2总光度达到峰值L ~ 1042 ergs-1，形成总质量Mtot ~ 1011 M的星系。当这些源位于红移z ~ 8处时，可以用SAFIR探测器探测到9.7 μm处的0-0 S（3）和17 μm处的0-0 S（1）转动谱线。寻找这种H2发射体的一个有效方法是观察Lyα发射体，因为最亮的H2发射体在Lyα发射中也是发光的。
We study the H2 cooling emission of forming galaxies and discuss their observability using the future infrared facility Single Aperture Far-Infrared Observatory (SAFIR). Forming galaxies with mass ≲1011 M☉ emit most of their gravitational energy liberated by contraction in molecular hydrogen line radiation, although a large part of thermal energy at virialization is radiated away by the hydrogen Lyα emission. For more massive objects, the degree of heating due to dissipation of kinetic energy is so great that the temperature does not drop below 104 K, and the gravitational energy is emitted mainly by the Lyα emission. Therefore, the total H2 luminosity attains the peak value of L ~ 1042 ergs s-1 for forming galaxies whose total mass Mtot ~ 1011 M☉. If these sources are situated at redshift z ~ 8, they can be detected by rotational lines of 0-0 S(3) at 9.7 μm and 0-0 S(1) at 17 μm by SAFIR. An efficient way to find such H2 emitters is to look at the Lyα emitters, since the brightest H2 emitters are also luminous in Lyα emission.