2012/08/01 by Bruce G. Elmegreen
Physics and Astronomy · #Accretion (finance) #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Milky Way #Molecular cloud #Spiral (railway) #Spiral galaxy #Star formation #astro-ph.GA
paper · pdf · doi:10.1017/s1743921313000197
published in Proceedings of the International Astronomical Union 8(S292), 35-38 (Cambridge University Press) · 4 pages, IAU Symposium 292, Beijing, August 2012
openalex publication_date 2012/08/01 · arxiv created 2013/09/12 · arxiv updated 2015/06/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract CO clouds can be non-self-gravitating in high pressure environments, while most should be strongly self-gravitating at low metallicities and ambient pressures. In the LMC, which is HI-rich, GMC formation and destruction should generally include molecule formation and destruction. In M51, which is CO-rich, GMCs grow by coalescence. The Milky Way is between these two situations. In all cases, large clouds form by accretion of gas and smaller clouds independently of the presence of molecules. GMCs in the Milky Way are analogous to dust lanes and spurs in other galaxies. The virial parameter α usually decreases monotonically with increasing cloud mass in surveys, which implies that small scale structure is formed by turbulence. Hierarchies of sequences with decreasing α should be present in cloud complexes from sub-solar masses up to the ambient Jeans mass (10 7 M ⊙ ).