NOAO > Observing Info > Approved Programs > 2004A-0022
|
NOAO > Observing Info > Approved Programs > 2004A-0022 |
|
PI: Deidre Hunter, Lowell Observatory, dah@lowell.edu
Address: 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA
Title: The Stellar Edges of Irregular Galaxies: What's Going on Out There?
Abstract:
There is considerable interest in, and ignorance of, the outer parts
of disk galaxies. Galactic outer edges are the interaction zone between
galactic and intergalactic material and are also most sensitive to
galaxy-galaxy interactions. Dwarf irregular (Im) galaxies, in
particular, may be particularly sensitive to their external environment.
Therefore, I am proposing to continue my exploration of the stellar
populations in the outer parts of nearby Im galaxies through very deep
BV imaging. These data are used to determine how far out various
stellar populations extend, how the stars are distributed, and what the
star formation history at the edges of irregular galaxies has been.
Results so far have been surprising: 1) The starlight continues without
an edge well beyond where stars are seen forming today, contrary to
predictions of several models; 2) The radial surface brightness profile
abruptly changes slope in one galaxy and not in another; and 3) The
color remains constant, implying continuous and normal star formation
even in the outer parts. I want to see if these unusual features are
found in other Im systems.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
|
NOAO > Observing Info > Approved Programs > 2004A-0022 |
|