The Baryon Content of Extremely Low Mass Dwarf Galaxies

Details The Baryon Content of Extremely Low Mass Dwarf Galaxies The Baryon Content of Extremely Low Mass Dwarf Galaxies

2006-08-14

arxiv.org/abs/astro-ph/0608295v1

Astrophys.J.653:240-254,2006

Astronomy and Astrophysics

Astrophysics

33 pages, 8 figures. Accepted to ApJ. Data available at http://www.ociw.edu/~mgeha/research

Scientific paper

10.1086/508604

We investigate the gas content and baryonic Tully-Fisher relationship for extremely low luminosity dwarf galaxies in the absolute magnitude range -13.5 > Mr > -16. The sample is selected from the Sloan Digital Sky Survey and consists of 101 galaxies for which we have obtained follow-up HI observations using the Arecibo Observatory and Green Bank Telescope. This represents the largest homogeneous sample of dwarfs at low luminosities with well-measured HI and optical properties. The sample spans a range of environments, from dense groups to truly isolated galaxies. The average neutral gas fraction is f_gas=0.6, significantly exceeding that of typical gas-rich galaxies at higher luminosities. Dwarf galaxies are therefore less efficient at turning gas into stars over their lifetimes. The strong environmental dependence of the gas fraction distribution demonstrates that while internal processes can reduce the gas fractions to roughly f_gas=0.4, external processes are required to fully remove gas from a dwarf galaxy. The average rotational velocity of our sample is vrot=50 km/s. Including more massive galaxies from the literature, we fit a baryonic Tully-Fisher slope of M_baryon \propto vrot^(3.70+/- 0.15). This slope compares well with CDM models that assume an equal baryon to dark matter ratio at all masses. While gas stripping or other processes may modify the baryon to dark matter ratio for dwarfs in the densest environments, the majority of dwarf galaxies in our sample have not preferentially lost significant baryonic mass relative to more massive galaxies.

Affiliated with

Also associated with

No associations

Rating

The Baryon Content of Extremely Low Mass Dwarf Galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Baryon Content of Extremely Low Mass Dwarf Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Baryon Content of Extremely Low Mass Dwarf Galaxies will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-100026