The authors have identified several satellite galaxies confined to a plane in their orbits around our nearest neighbor, the Andromeda Galaxy. Such a planar structure is perhaps at odds with our current understanding of galaxy formation.
For the first time, diffuse X-ray emission from young stars is identified in the Small Magellanic Cloud (SMC), using data from Chandra.
Pairs of dwarf galaxies in the Local Group are much more common than what expected from N-body/semi-analytic models of galaxy formation.
In this paper, the authors describe a new galaxy simulation that includes molecular hydrogen, the site of star formation, and discuss what happens with and without it.
It’s an unpleasant fact of galactic astrophysics that most of the molecular gas in nearby galaxies is completely undetectable.
“A galaxy is a gravitationally bound collection of stars whose properties cannot be explained by a combination of baryons and Newton’s laws of gravity.” (Willman & Strader, http://arxiv.org/abs/1203.2608)