Outer disks of S0-Sb gal. II. Surface-brigthness

Following very careful sky subtraction, the profiles can typically be determined down to brightness levels well below 27mag/arcsec^2^ and in the best cases below 28mag/arcsec^-2^. We classified the profiles according to the scheme used previously for the barred sample: Type I profiles are single unbroken exponential radial declines in brightness; Type II profiles ("truncations") have an inner shallow slope (usually exponential) which changes at a well-defined break radius to a steeper exponential; and Type III profiles ("antitruncations") have an inner exponential that is steeper, giving way to a shallower outer (usually exponential) decline.

By combining these profiles with previous studies, we can make the first clear statements about the trends of outer-disk-profile types along the Hubble sequence (including both barred and unbarred galaxies), and their global frequencies.