How the existence of unstable neutral media restricts the aspect ratio of cold neutral media?
| العنوان: | How the existence of unstable neutral media restricts the aspect ratio of cold neutral media? |
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| المؤلفون: | Ka Wai Ho, Ka Ho Yuen, Alex Lazarian |
| المصدر: | Monthly Notices of the Royal Astronomical Society. 521:230-240 |
| بيانات النشر: | Oxford University Press (OUP), 2023. |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies |
| الوصف: | The ubiquity of very thin and lengthy cold neutral media (CNM) has been reported by multiple authors in the HI community. Yet, the reason of how the CNM can be so long and lengthy is still in debate. In this paper, we recognize a new type of instability due to the attractive nature of the pressure force in the unstable phase. We provide a new estimation of the average CNM filament aspect ratio with the consideration of force balances at the phase boundary, which is roughly 5-20 in common CNM environment. We show that most of the cold filaments are less filamentary than what usually predicted via MHD turbulence theory or inferred from observations: The average length of CNM filament is roughly 1/2 of that in isothermal MHD turbulence with similar turbulence conditions. This suggests that the "cold filaments" that is identified in observations might not be in pressure equilibrium or generated via other mechanisms. Comment: 10 pages, 7 figures, accepted by MNRAS |
| تدمد: | 1365-2966 0035-8711 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::465995969c3ad797667138893dfc25ab https://doi.org/10.1093/mnras/stad481 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....465995969c3ad797667138893dfc25ab |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 13652966 00358711 |
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