Role of cosmic rays in the early stages of galactic outflows
Role of cosmic rays in the early stages of galactic outflows
复制标题
宇宙射线在银河流出早期阶段的作用
DOI：
10.1093/mnras/staa2025
复制
发表时间：
2020
影响因子：
4.8
通讯作者：
B. Nath
中科院分区：
文献类型：
--
作者：
Ranita Jana;Siddhartha Gupta;B. Nath
Using an idealized set-up, we investigate the dynamical role of cosmic rays (CRs) in the early stages of galactic outflows for galaxies of halo masses 108, 1011, and 1012 M⊙. The outflow is launched from a central region in the galactic disc where we consider three different constant star formation rates (0.1, 1, and 10 $\mathrm{M}_\odot \, \mathrm{yr}^{-1}$) over a dynamical time-scale of 50 Myr. We determine the temperature distribution of the gas and find that CRs can reduce the temperature of the shocked gas, which is consistent with previous results. However, we show that CRs do not have any noticeable effect on the mass loading by the outflow. We find that CRs can reduce the size of the outflow, which contradicts previous claims of efficient dynamical impact of CRs; however, it is consistent with earlier theoretical models of CR-driven blastwave as well as stellar wind. We discuss the dependence of our results on CR injection prescriptions and compare them with earlier studies. We conclude that in the early stages of galactic outflows the dynamical role of CRs is not important.
