Radial Distributions of Dark and Luminous Matter in Bright Spiral Galaxies

Abstract

We present a work in progress investigating the radial distributions of dark and luminous matter in local bright spiral galaxies spanning a range of Hubble types. the distributions are derived from multiband imaging (BVRJHK) predominately from the Ohio State University Bright Spiral Galaxy Survey (OSUBSGS) and rotation curves from the literature. We use stellar colour-MIL relationships from Bell & de Jong (2001, ApJ, 550, 212) to create radial stellar mass surface density profiles for each of our galaxies. These profiles are used to create rotation curves for the stellar component; gas masses are derived from HI when available. the resulting stellar and gas mass rotation curves are compared to observed (total mass) rotation curves, and the rotation due to dark matter is determined for each galaxy. Fits to Navarro, Frenk, & White (1996, ApJ, 462, 563; NFW) halo profiles are shown. We present this analysis for 2 example galaxies from our sample of nearly 50. We will use this data to investigate correlations between these mass components and physical properties of galaxies.