Galaxy-halo connection and near-field cosmology with numerical and semi-analytic methods
The small-scale issues of
There are many missing small satellite galaxies.
Deduce the properties of galaxies from the ones of DM halos
Compaction only happens at high-z.
Condition for compaction:
Major merger
Counter-rotating stream
Disk instability: Toomre instability
There is no observed compaction in simulations with strong feedback.
Take home message
