Molecular Tracers of High-Mass Star Formation in External Galaxies
Molecular Tracers of High-Mass Star Formation in External Galaxies
复制标题
外部星系中高质量恒星形成的分子示踪剂
DOI：
10.1086/528678
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
J. Rawlings
中科院分区：
文献类型：
--
作者：
E. Bayet;S. Viti;David A. Williams;J. Rawlings
在高红移的外部活动星系中应该可以检测到热核分子。我们在这里对恒星形成区域的化学成分进行了详细研究，这些物理条件与银河系可能适合的物理条件有很大不同。我们特别研究了分子丰度随时间变化的趋势以及相关物理参数的变化。这些参数包括金属丰度、尘埃：气体质量比、H2 形成速率、相对初始元素丰度、宇宙射线电离速率和热核心温度。这些趋势表明不同的示踪剂如何提供有关身体状况和进化年龄的信息。我们确定了几个观测到的星系的热核示踪剂，这些星系被认为代表螺旋星系、活动星系、低金属丰度星系和高红移星系。即使在低金属丰度的例子中，许多潜在的分子示踪剂也应该以足够高的水平存在，以允许对包含大量热核心的高红移活动星系进行未解析的检测。
Hot-core molecules should be detectable in external active galaxies out to high redshift. We present here a detailed study of the chemistry of star-forming regions under physical conditions that differ significantly from those likely to be appropriate in the Milky Way Galaxy. We examine, in particular, the trends in molecular abundances as a function of time with respect to changes in the relevant physical parameters. These parameters include metallicity, dust:gas mass ratio, the H2 formation rate, relative initial elemental abundances, the cosmic-ray ionization rate, and the temperature of hot cores. These trends indicate how different tracers provide information on the physical conditions and on evolutionary age. We identify hot-core tracers for several observed galaxies that are considered to represent spiral galaxies, active galaxies, low-metallicity galaxies, and high-redshift galaxies. Even in low-metallicity examples, many potential molecular tracers should be present at levels high enough to allow unresolved detection of active galaxies at high redshift containing large numbers of hot cores.