THE JCMT GOULD BELT SURVEY: EVIDENCE FOR DUST GRAIN EVOLUTION IN PERSEUS STAR-FORMING CLUMPS

The dust emissivity spectral index, beta, is a critical parameter for deriving the mass and temperature of star-forming structures and, consequently, their gravitational stability. The beta value is dependent on various dust grain properties, such as size, porosity, and surface composition, and is expected to vary as dust grains evolve. Here we present beta, dust temperature, and optical depth maps of the star-forming clumps in the Perseus Molecular Cloud determined from fitting spectral energy distributions to combined Herschel and JCMT observations in the 160, 250, 350, 500, and 850 mu m bands. Most of the derived beta and dust temperature values fall within the ranges of 1.0-2.7 and 8-20 K, respectively. In Perseus, we find the beta distribution differs significantly from clump to clump, indicative of grain growth. Furthermore, we also see significant localized beta variations within individual clumps and find low-beta regions correlate with local temperature peaks, hinting at the possible origins of low-beta grains. Throughout Perseus, we also see indications of heating from B stars and embedded protostars, as well evidence of outflows shaping the local landscape.