How cosmic rays mediate the evolution of the interstellar medium
| العنوان: | How cosmic rays mediate the evolution of the interstellar medium |
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| المؤلفون: | Christine M Simpson, Rüdiger Pakmor, Christoph Pfrommer, Simon C O Glover, Rowan Smith |
| المصدر: | Monthly Notices of the Royal Astronomical Society. 520:4621-4645 |
| بيانات النشر: | Oxford University Press (OUP), 2022. |
| سنة النشر: | 2022 |
| مصطلحات موضوعية: | Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics::Galaxy Astrophysics |
| الوصف: | We explore the impact of diffusive cosmic rays (CRs) on the evolution of the interstellar medium (ISM) under varying assumptions of supernova explosion environment. In practice, we systematically vary the relative fractions of supernovae (SN) occurring in star-forming high-density gas and those occurring in random locations decoupled from star-forming gas to account for SN from run-away stars or explosions in regions that have been cleared by prior SN, stellar winds, or radiation. We explore various mixed models by adjusting these fractions relative to each other. We find that in the simple system of a periodic stratified gas layer the ISM structure will evolve to one of two solutions: a "peak driving" state where warm gas is volume filling or a "thermal runaway" state where hot gas is volume filling. CR pressure and transport are important factors that strongly influence the solution state the ISM reaches and have the ability to flip the ISM between solutions. Observable signatures such as gamma ray emission and HI gas are explored. We find that gamma ray luminosity from pion decay is largely consistent with observations for a range of model parameters. The thickness of the HI gas layer may be too compact, however, this may be due to a large cold neutral fraction of midplane gas. The volume fraction of hot gas evolves to stable states in both solutions, but neither settles to a Milky Way-like configuration, suggesting that additional physics which is omitted here (e.g. a cosmological circum-galactic medium, radiation transport, or spectrally resolved and spatially varying CR transport) may be required. Comment: 27 pages, 21 Figures, submitted to MNRAS, comments welcome |
| تدمد: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stac3601 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e6e7a35ac5df31b30c505e84b27ac51e https://doi.org/10.1093/mnras/stac3601 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....e6e7a35ac5df31b30c505e84b27ac51e |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 13652966 00358711 |
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| DOI: | 10.1093/mnras/stac3601 |