Title:	Role of cosmic rays in the early stages of galactic outflows
Authors:	Jana, Ranita Gupta, Siddhartha Nath, Biman B.
Keywords:	stars winds outflows – ISM cosmic rays – galaxies star formation – galaxies evolution – galaxies starburst
Issue Date:	Sep-2020
Publisher:	Oxford University Press on behalf of the Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2020, Vol.497, p2623–2640
Abstract:	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 M 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.
Description:	Open Access
URI:	http://hdl.handle.net/2289/7562
ISSN:	0035-8711 1365-2966 (online)
Alternative Location:	https://academic.oup.com/mnras/article/497/3/2623/5870111 http://dx.doi.org/10.1093/mnras/staa2025 https://arxiv.org/abs/2007.00696
Copyright:	2020 The Author(s)
Appears in Collections:	Research Papers (A&A)

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