Gas accretion in nearby spiral galaxies

Abstract:

The fraction of the available baryons in the dark matter halos around galaxies like our own Milky Way that have cooled and been transformed into stars is only around 20 percent. If one compares the star formation rates in these galaxies to the amount of atomic and molecular gas that they contain, one infers that gas should be accreting from the external environment in order maintain star formation at its observed level. There is observational evidence-such as neutral hydrogen (HI) cloud complexes, HI-rich dwarfs in the vicinity of spiral galaxies, extended and warped outer layers of HI in spiral galaxies-that nearby galaxies accrete material in the form of atomic gas. Systematic surveys of such features are still lacking, however, so their ubiquity and their link to the growth of galactic disks still remains poorly understood. We propose to observe a sample of very gas-rich galaxies to determine how these galaxies accreted …

Año de publicación:

2012

Keywords:

Fuente:

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