Radial Structure of Galactic Stellar Disks

We present the results from our deep optical imaging survey µ V lim ≈ 26 − 27 mag/ 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 galactocen-tric 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.