HI Observations of SA 68-6597: the faintest Blue Compact Dwarf Galaxy

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

5 pages, accepted for publiction in ApJ Letters

Scientific paper

10.1086/491645

Blue compact dwarf galaxies (BCDs) are faint (M(B) < -17 mag) compact (R <1 kpc), at least qualitatively very blue galaxies due to active star formation, and have low metallicities. Found serendipitously as part of a redshift survey of faint galaxies with the Keck Telescope (DEEP), SA 68-6597 is at a distance of 80 Mpc, and is one of the faintest, -12.4 mag, lowest metallicity, ~0.05 Z(sun), BCDs known. Its H-beta linewidth of sigma =27 km/s and small size, R(eff) ~ 190 pc, suggest that it is an extremely low mass galaxy. We have used the Arecibo telescope to measure the HI properties of SA 68-6597 in order to better constrain its total mass and its potential for future star formation. SA 68-6597 has a M(HI) = (1.4+-0.4)x10^7 M(sun) and an HI FWHM linewidth of 33$\pm^{60}_{12}$. Combining the HI linewidth with an estimate of the size of the HI disk, we derive a M(dyn)>~3x10^7 M(sun). The M(HI)/L(B)=1.0+-0.3 M(sun)/L(sun), M(dyn)/L(B) >= 2 M(sun)/L(sun) and M(HI)/M(dyn) <~ 0.47 values are typical for BCDs. Combining the measured star formation rate of 0.003 M(sun)/yr with the HI mass, we derive a gas depletion timescale of 5+-2 Gyr. While SA 68-6597 is a fainter, lower-mass, higher metallicity counterpart to other BCDs like I Zw 18 and SBS 0335-052, its HI properties suggest it will not evolve dramatically in the near future. Given the limits on its gaseous and dynamical masses, SA 68-6597 may be able to evolve into a moderately massive dwarf spheroidal galaxy.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

HI Observations of SA 68-6597: the faintest Blue Compact Dwarf Galaxy 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 HI Observations of SA 68-6597: the faintest Blue Compact Dwarf Galaxy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and HI Observations of SA 68-6597: the faintest Blue Compact Dwarf Galaxy will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-46080

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.