HI Holes, Shells and Star Formation in LITTLE THINGS Galaxies
Abstract
We present the physical properties of atomic hydrogen (HI) gas distribution in nearby dwarf galaxies as part of the LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey). We use high spatial and velocity resolution HI data from the survey to identify and analyze the HI holes and calculate the surface and the volume porosity in each galaxy. We find some LITTLE THINGS galaxies with no star formation regions have high porosities. This result is consistent with the idea that these galaxies are too porous to continue star formation. The sample galaxies with the lowest porosities and no star formation may suggest the necessity of recent star formation to form the holes. We estimate the star formation rate from the energy required to create a hole which is consistent with the star formation rates measured from visible and far ultraviolet spectral data, suggesting that the stellar feedback can be considered as a factor in creating HI holes.
- Publication:
-
American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23346005P