Title:

The SINGS Spitzer Legacy: Seeing Nearby Galaxies in a New Light



JD Smith
Steward Observatory



Abstract:

The Spitzer Space Telescope is revolutionizing our understanding of star
formation and the dusty interstellar media of galaxies.  The
unprecedented resolution and sensitivity of the Spitzer images, when
combined with observations at ultraviolet, visible, and radio
wavelengths, are providing for the first time complete, detailed maps of
the current star formation covering the full range of interstellar
environments and evolutionary stages.  The same data delineate the
structure and topology of the cold ISM in galaxies with unprecedented
depth and detail. The Spitzer mid-infrared spectra provide information
on the physical conditions in all phases of gas, from the ionized
regions surrounding massive stars to the surrounding PDR, neutral,
molecular, and shocked environments.

This talk will highlight results from the Spitzer Infrared Nearby
Galaxies Survey (SINGS), a comprehensive, multi-wavelength Legacy survey
of 75 nearby galaxies that span the full range of types, luminosities,
and infrared properties found in the local universe, with a special
emphasis on the power of spatially resolved spectroscopy to probe the
variable mid-infrared emission spectrum of star-forming galaxies, and
the surprising role low-luminosity AGN are playing in modifying the
fundamental mid-infrared star-formation tracer -- the PAH molecular
emission bands.