5MUSES

The 5mJy Unbiased Spitzer Extragalactic Survey (5 Muses) is a mid-infrared spectroscopic survey of 330 galaxies with the Infrared Spectrograph (IRS). The targets all have 24-micron flux densities of 5-100 mJy, and cover a wide range of infrared luminosity (1×10¹⁰ L_☉ to more than 1×10¹³  L_☉) and redshift (with most falling between 0.05 < z < 1.0), and are selected from the Spitzer FLS and SWIRE survey fields. The sample bridges the gap between the bright, nearby infrared galaxies known before Spitzer (e.g. the LIRGs and ULIRGs discovered with IRAS and ISO), and the much fainter, more distant sources which have been the focus of much of the dedicated Spitzer IRS follow-up to date. The legacy of the 5 Muses survey will be a library of high quality IRS spectra that will be critical for providing (1) a statistically complete accounting of the relative contribution of stars and AGN in IR-bright galaxies, (2) an overview of the prevailing physical conditions in the dusty ISM in galaxies over the past 2-5 Gyr, and (3) a proper modeling of the number counts and backgrounds in the infrared out to z=1, and a critical resource for future missions like WISE, Herschel and JWST.