Locally, parts of the gas do collapse and form those little dense blobs that fly off. But the sphere as a whole has too much energy - each section of the cloud is moving at greater than the overall escape velocity, so it's doomed to explode. Since the velocity field is complicated, parts of the cloud collide with each other, forming locally gravitationally bound substructures. Pressure waves are probably important for the small structures, but probably not for the overall cloud. Sound speed is equivalent to a crossing time of about 200 Myr, a bit longer than what's shown here.
MHD?
ReplyDeleteWhy didn't it collapse gravitationally and how did it start off as a sphere? Sound waves might play a role as well.
ReplyDeleteLocally, parts of the gas do collapse and form those little dense blobs that fly off. But the sphere as a whole has too much energy - each section of the cloud is moving at greater than the overall escape velocity, so it's doomed to explode. Since the velocity field is complicated, parts of the cloud collide with each other, forming locally gravitationally bound substructures.
ReplyDeletePressure waves are probably important for the small structures, but probably not for the overall cloud. Sound speed is equivalent to a crossing time of about 200 Myr, a bit longer than what's shown here.
Rhys Taylor Pressure is a measure of the kinetic energy density so you've given it an initial pressure, in some sense.
ReplyDeleteIs this simulation Eulerian or Lagrangian?