Session 77 - Structures of Galaxies.
Display session, Friday, January 09
Exhibit Hall,

## [77.04] The Frequency of Inner-truncated Disks

W. E. Baggett (CSC/STScI), K. S. J. Anderson (NMSU), S. M. Baggett (STScI)

We have performed bulge-disk decomposition on a sample of 659 spiral and lenticular galaxy brightness profiles from the Photometric Atlas of Northern Bright Galaxies (1990, Kodaira, et al.), and have used those fits to analyze the frequency of occurrence of inner-truncated disks. We selected a 76% complete sample containing 218 galaxies by choosing galaxies with profile fits having morphological types from S0 through Sdm (-3.5\leq T\leq 9.5), inclination \leq 60\deg (R_25\leq 0.3), declination north of -25\deg, and a total apparent magnitude brighter than 12.5 (B_T \leq 12.5); the complete sample of 286 galaxies was defined from the Third Reference Catalogue of Bright Galaxies (1991, deVaucouleurs, et al.) using the same selection criteria. Interacting galaxies were excluded from both samples. Excluding brightness profiles with the inner-truncation fitted to outer arms or rings and before completeness corrections, we find that approximately 28% of all galaxies exhibit inner-truncations, a rate that increases to almost 50% for the barred galaxy subsample.