Counting the number of galaxies at a given mass in a region of space gives you the number density – something that can be really easily compared to simulations. But do our observations and theory match up? And how does looking out to higher and higher redshifts help us to better understand our Universe…
Observations of dwarf galaxies show that sites of active star formation have fewer metals. These galaxies may have been diluted by the impact of pristine gas from the cosmic web.
Astronomers have known for a while that GRBs are sign-posts to galaxies which are forming lots of stars. But today’s paper used radio observations of the gas to connect that star formation to a recent merger.
In today’s paper, the authors use Cepheid distance moduli to study the structure of the SMC.
The authors of today’s paper created simulated galaxies, for which true properties are known. They then used synthetic observations to compare the true answers to the values observers would expect to recover.
Dark matter permeates the Universe and surrounds every galaxies in the form of dark matter halos. We don’t really know dark matter works, as predictions of standard cosmology, Lambda Cold Dark Matter (ΛCDM), are way off from observations. Is this the death of Cold Dark Matter, or there are something more to it?