Spitzer Infrared Nearby Galaxies Survey (SINGS) imaging of NGC 7331:: A panchromatic view of a ringed galaxy

Well-resolved infrared observations of nearby galaxies are of fundamental importance to the study of the processes that affect galactic evolution. In this paper we report on the first imaging results from the Spitzer Infrared Nearby Galaxies Survey ( SINGS) using observations of the Sb galaxy NGC 7331. We present images of NGC 7331 over a large range of wavelengths that allow us to compare the distributions of gas, stars, and dust in unprecedented detail. As an example of the types of information that the full SINGS will provide, we use three methods to determine that the interstellar medium mass in the ring of NGC 7331 is similar to5 x 10(9) M-circle dot. We also present the first images showing emission from small hot (similar to1000 K) dust grains, but we show that these dust grains contribute only a small fraction of the integrated 4.5 mum emission from NGC 7331.