PI: Letizia Stanghellini, NOAO, firstname.lastname@example.org
Address: PO Box 26732, 950 North Cherry Avenue, Tucson, AZ 85726-6732, USA
CoI: Laura Magrini, Arcetri Observatory
CoI: Viviana Casasola, IRA-INAF Bologna
Title: The M81 radial metallicity gradient and its discontinuity through HII region weak-line abundances
Abstract: We propose to study the alpha-element abundances in remote H II regions of M81 to determine a possible radial metallicity break near the corotation radius that is hinted for its disk. M81 is one of the few nearby spiral galaxies where weak-line abundances are known for a large sample of H II regions and also for PNe, which are essential to get a timeline of metallicity events across the disk. With the proposed observations we plan to: (1) confirm that a metallicity break does exist; (2) find the slope(s) for both the inner and the outer galactic regions; and (3) relate these gradients to the PN alpha-element distribution, to pinpoint the stability of the abundance pattern and the galactic evolutionary history.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360