Dependence of Galaxy Structure on Rest‐Frame Wavelength and Galaxy Type

We present a quantitative analysis of the morphologies for 199 nearbygalaxies as parameterized with measurements of the concentration, asymmetry,and clumpiness (CAS) parameters at wavelengths from 0.15-0.85 micrometers. Wefind that these CAS parameters depend on both galaxy type and the wavelength ofobservation. As such, we use them to obtain a quantitative measure of the"morphological k-correction", i.e., the change in appearance of a galaxy withrest-frame wavelength. Whereas early-type galaxies (E--S0) appear about thesame at all wavelengths longward of the Balmer break, there is a mild butsignificantly-determined wavelength-dependence of the CAS parameters forgalaxies types later than S0, which generally become less concentrated, andmore asymmetric and clumpy toward shorter wavelengths. Also, as a mergerprogresses from pre-merger via major-merger to merger-remnant stages, itevolves through the CAS parameter space, becoming first less concentrated andmore asymmetric and clumpy, and then returning towards the "locus" of normalgalaxies. The final merger products are, on average, much more concentratedthan normal spiral galaxies.Comment: 28 pages, LaTeX2e, 17 figures, 9 tables, and a modified class file emulateapj_rj.cls are included. Accepted for publication in The Astrophysical Journa