Quote:
Originally Posted by Jarvamundo
Yeah, this is where i'm having difficulties swallowing the hypothesis of gas coalescing under gravity in that active environment.
Anyways, thanks for your input.
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Actually, it's more likely to coalesce in that environment than it otherwise would because of all the interactions that are going on. The high energy radiation in those areas tends to form shock waves and turbulence which causes Bok globules and such to contract when they run into them. However, that ionising radiation can also destroy them as well, so it's a matter of balance and good luck (plus, just how dense the globules are and how big they are, etc). Once the clouds exceed their Jeans Masses, gravity can do a very good job of holding onto the material to form the stars. However, to form those really big stars, they have to be in high energy, dense environments because once stars start to form, it's easy to form smaller stars than larger ones. The clouds tend to fragment into smaller protostars because of the internal dynamics of the globules and to form the larger stars, the surrounding conditions have to balance out those internal dynamics. Usually, clouds of relatively high metallicity form smaller stars as their Jeans Masses are relatively low before they begin collapse.
Those monsters in R136 probably formed out of protostellar clouds with Jeans Masses up around the 5000-10000 solar masses before the clouds began to contract and fragment into protostars. The low metallicity means the clouds were far more transparent to radiation than a typical cloud in the Galaxy and their cores were less dense when collapse begins. Because of the properties of the gases they formed out of, the protostars in these large clouds stay relatively large and the clouds don't fragment as much. Hence, larger stars.