Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-07-27
Astrophys.J.630:L25-L28,2005
Astronomy and Astrophysics
Astrophysics
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.
Koo David C.
Noeske Kai Gerhard
Phillips Andrew C.
Pisano Daniel J.
Willmer Christopher N. A.
No associations
LandOfFree
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.
Profile ID: LFWR-SCP-O-46080