A WISE View of Nearby Spiral Galaxies: mapping the spatial distribution of
star formation and stellar mass along the Hubble sequence

Frank Masci, Thomas Jarrett, Chao-Wei Tsai, Dominic Benford, David Leisawitz,
and the WISE Team

Spiral density waves are believed to trigger star formation (SF) in spiral arms
and determine the gaseous and dynamic evolution of galactic disks. The
Wide-field Infrared Survey Explorer (WISE) offers a unique opportunity to study
spiral structure in thousands of galaxies by tracing SF in the mid-IR (12 \&
22 $\mu$m) and old stellar populations in the near-IR (3.4 \& 4.6 $\mu$m).
We present early results of a pilot study of spiral structure in several
grand-design and optically flocculent spirals exhibiting varying degrees of
bulge/disk size ratio, spiral-arm pitch angle, and absence/presence of bars.
We combine the WISE data with archival UV data to explore the spatial
distribution of specific SF rate, stellar mass surface density and
PAH emission across all morphologies. To better match spatial resolutions
across wavelengths and accentuate structure on small scales, we use a
resolution enhancement (HiRes) algorithm specifically designed for WISE.
We validate our photometric procedures and SF indicators by comparing to
Spitzer measurements of the classic grand-design spiral: NGC 5194 (M51a).