NOAO > Observing Info > Approved Programs > 2006A-0562
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NOAO > Observing Info > Approved Programs > 2006A-0562 |
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PI: R. Michael Rich, UCLA, rmr@astro.ucla.edu
Address: Division of Astronomy and Astrophysics, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547, USA
CoI: Enrico V. Held, Osservatorio Astronomico Padova
CoI: Luca Rizzi, University of Hawaii
CoI: Ivo Saviane, European Southern Observatory
CoI: Danielle Alloin, CEA
CoI: Fabio Bresolin, University of Hawaii
Title: Near-Infrared Luminosities and Nebular Oxygen Abundances of Dwarf Irregular Galaxies in the M81 group
Abstract:
The existence of a luminosity-metallicity (L-Z) relation for dwarf
irregular galaxies is still debated (see rationale) partly because the
catalogs of abundances are based on inhomogeneous data, luminosities are
derived from blue light, and the effect of environment is not
considered. Since a few years we've started a modern investigation to
obtain oxygen abundances and near-IR luminosities for a sample of dIrr
in the three most nearby galaxy groups. Our data for the Sculptor and
M81 groups are beginning to shed some light over the controversy, but
secure conclusions are undermined by the too few available data for M81
dwarfs. So now we propose to add more evidence by collecting more
imaging and spectra of HII regions in the M81 group. With these data:
(a) we will derive a homogeneous catalog of abundances; (b) the best
measure of total stellar mass, the infrared luminosity will be obtained;
(c) the distance uncertainties will be reduced thanks to the stretch in
galaxy luminosity which is observed in the near-IR; and (d) the L-Z
relation for the M81 group will be compared to that available for the
Scl group, thus checking the influence of the environment.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
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NOAO > Observing Info > Approved Programs > 2006A-0562 |
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