Stripping All Traces of Star-Forming Gas
National Radio Astronomy Observatory | 2014 Oct 15
Astronomers using the National Science Foundation’s Green Bank Telescope (GBT) in West Virginia, along with data from other large radio telescopes, have discovered that our nearest galactic neighbors, the dwarf spheroidal galaxies, are devoid of star-forming gas, and that our Milky Way Galaxy is to blame.
These new radio observations, which are the highest sensitivity of their kind ever undertaken, reveal that within a well-defined boundary around our Galaxy, dwarf galaxies are completely devoid of hydrogen gas; beyond this point, dwarf galaxies are teeming with star-forming material.
The Milky Way Galaxy is actually the largest member of a compact clutch of galaxies that are bound together by gravity. Swarming around our home Galaxy is a menagerie of smaller dwarf galaxies, the smallest of which are the relatively nearby dwarf spheroidals, which may be the leftover building blocks of galaxy formation. Further out are a number of similarly sized and slightly misshaped dwarf irregular galaxies, which are not gravitationally bound to the Milky Way and may be relative newcomers to our galactic neighborhood. ...
The Dearth of Neutral Hydrogen in Galactic Dwarf Spheroidal Galaxies - Kristine Spekkens et al
- Astrophysical Journal Letters 795(1) L5 (2014 Nov 01) DOI: 10.1088/2041-8205/795/1/L5
arXiv.org > astro-ph > arXiv:1410.0028 > 30 Sep 2014