Spitzer Space Telescope - Archive Research Proposal #50243


Star Formation and the Tully-Fisher Relation

Principal Investigator: Stacy McGaugh
           Institution: University of Maryland, College Park

     Technical Contact: Stacy McGaugh, University of Maryland, College Park

Co-Investigators: 
Jim Schombert, University of Oregon                                   
Erwin de Blok, University of Capetown                                 

Science Category: nearby galaxies (z<0.05, v_sys<15,000 km/s) 
Dollars Approved: 25000 

Abstract:
We propose to investigate the Tully-Fisher (TF) relation in archival Spitzer
data. The slope of the TF relation, which is the most fundamental relationship
reflecting galaxy formation scenarios, increases from B to K band passes, and
the scatter around the relation decreases over the same range. We seek to
determine if this trend continues, or if it saturates at a value set by an
intrinsic relation between mass and rotation velocity. Indeed, this intrinsic
"baryonic" Tully-Fisher relation provides the one of the most direct test of
galaxy formation scenarios. Our target sample possesses extensive supporting
data, including BVJK photometry (at a minimum; other bands and Halpha are often
available) and high quality extended HI velocity fields. We will use these data
to measure the impact of extinction and star formation on the intrinsic TF
relation, and to test the efficacy of competing estimators of the stellar mass.
This will produce an empirical calibration of the Spitzer Tully-Fisher relation
and insight into its physical significance.