Angular momentum of galaxy disks

[hellfire]

As you can read in http://pinot.phys.uvic.ca/~jfn/mywebpage/gxform.html, recent simulations show that the accepted model of dissipational collapse for the formation of galaxy disks, leads to an excessive loss of angular momentum in the disk when mergers are considered. What are the current hypothesis to solve this problem?

 

[ohwilleke]

This is one of the stronger arguments for MOND which naturally predicts the observed result.

 

[Nereid]

I have no idea whether it's totally dead, or merely dormant, but Peratt (he of 'plasma cosmology' fame) made a big song and dance back in the (19)80s about Birkeland currents etc, and somehow managed to get humungeous amounts of (then) supercomputer time to do similations (of spiral galaxies?), leading to some (to me) handwaving about pattern similarity ... whether anyone followed up with more focussed (from my POV, of course) similations, I have no idea!

 

[Chronos]

That result does not appear to have yet been published. Perhaps it is a work in progress. There are a number of different approaches to disk formation. None are entirely satisfactory. Galactic evolution is a very complicated field of study and observational data has not beem of the quality and quantity needed to crack the case. We are, however, making good strides. Anyways, here is a very recent paper addressing the issue of disk formation and angular momentum:

A Merger-Driven Scenario for Cosmological Disk Galaxy Formation
http://www.arxiv.org/abs/astro-ph/0503369

 

[hellfire]

I took a look to the original paper of Navarro and White written in 1993 and the simulations were done without taking into account the stellar evolution, i.e. energy injection due to stellar winds and supernovae. They seam to call this problem „overcooling”: most of the baryonic matter should collapse into very dense cores. Stellar winds and supernovae could heat the gas avoiding this early and efficient collapse. The problem seams to be related to the fact that the efficiency of galaxy formation was actually low and that there are lots of baryons in the intergalactic medium. If stellar winds and supernovae were indeed the reasons to avoid overcooling and loss of angular momentum, then the IGM should have a considerable metalicity. Is this understanding correct?