NOAO >   Observing Info >   Approved Programs >   2010A-0129

Small NOAO Logo

Proposal Information for 2010A-0129


PI: Guilin Liu, University of Massachusetts, gliu@astro.umass.edu
Address: Department of Astronomy, 710 N. Pleasant St., Amherst, MA 01003, USA

CoI: Daniela Calzetti, University of Massachusetts

Title: Exploring the Scaling Laws of Star Formation: the High Density Centers of Galaxies

Abstract: We propose to obtain H(alpha) and R-band images for a sample of 31 nearby star forming galaxies, which are part of an extensive investigation of the spatially-resolved Schmidt-Kennicutt Law of star formation in the high-density regime of the circumnuclear regions of galaxies. The proposed galaxies are part of a sample of 84, for which we have already obtained HST/NICMOS P(alpha) (1.876 (mu)m) images, which we are combining with archival interferometric CO maps. Line maps trace recent star formation, while CO traces the cold gas. The proposed H(alpha) observations will address two extant limitations in our current data: (1) presence of dust extinction which affects even P(alpha) by more than a factor of 2 in the centers of galaxies; (2) presence of low surface brightness line emission, not traced by HST. We will use the KPNO 2.1-m telescope images to remove dust extinction via the H(alpha)/P(alpha) ratio, and to trace the low-luminosity ionized gas surrounding the HII-region emission peaks. This will represent a unique sample of high-accuracy star formation rate measurements on physical scales of about 50 pc (the typical size of HII complexes). These observations will enable precise derivations of HII region luminosity functions and a thorough investigation of the scaling laws of star formation, and its dependence on the local environment. A previous proposal (ID 2009B-0397), to image 17 galaxies, has been approved for time, and the present proposal seeks to complete the H(alpha) imaging of our galaxy sample by requesting observations for the remaining 31 galaxies, thus providing a unique and \bf homogeneous survey of `dust- free' star formation.


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 >   2010A-0129

noaoprop-help@noao.edu

Small NOAO Logo