Radial structure of galactic stellar disks

Abstract

We present the results from our deep optical imaging survey μ_lim=26-27 V-mag/arcsec^2 of a morphologically selected sample of 72 edge-on disk galaxies. The question of the global structure of galactic stellar disks, especially the radial surface brightness profile at large galactocentric distances, is addressed. We find that typical radial profiles are better described by a two-slope exponential profile --characterised by an inner and outer scalelength separated at a break radius-- rather than a sharply-truncated exponential model. Results are given for three face-on equivalents, serving as the crucial test to assure the findings for the edge-on sample without possible geometrical line-of-sight effects.