Bolocam Survey for 1.1 mm Dust Continuum Emission in the c2d Legacy Clouds. I. Perseus

Abstract

We have completed a 1.1 mm continuum survey of 7.5 deg 2 of the Perseus Molecular Cloud using Bolocam at the Caltech Submillimeter Observatory. This represents the largest millimeter or submillimeter continuum map of Perseus to date. Our map covers more than 30,000 31'' (FWHM) resolution elements to a 1 σ rms of 15 mJy beam -1 . We detect a total of 122 cores above a 5 σ point-source mass detection limit of 0.18 M ☉ , assuming a dust temperature of T D = 10 K, 60 of which are new millimeter or submillimeter detections. The 1.1 mm mass function is consistent with a broken power law of slope α 1 = 1.3 (0.5 M ☉ < M < 2.5 M ☉ ) and α 2 = 2.6 ( M > 2.5 M ☉ ), similar to the local initial mass function slope (α 1 = 1.6, M < 1 M ☉ ; α 2 = 2.7, M > 1 M ☉ ). No more than 5% of the total cloud mass is contained in discrete 1.1 mm cores, which account for a total mass of 285 M ☉ . We suggest an extinction threshold for millimeter cores of A V ~ 5 mag, based on our calculation of the probability of finding a 1.1 mm core as a function of A V . Much of the cloud is devoid of compact millimeter emission; despite the significantly greater area covered compared to previous surveys, only 5-10 of the newly identified sources lie outside previously observed areas. The two-point correlation function confirms that dense cores in the cloud are highly structured, with significant clustering on scales as large as 2 × 10 5 AU. Our 1.1 mm emission survey reveals considerably denser, more compact material than maps in other column density tracers such as 13 CO and A V , although the general morphologies are roughly consistent. These 1.1 mm results, especially when combined with recently acquired c2d Spitzer Legacy data, will provide a census of dense cores and protostars in Perseus and improve our understanding of the earliest stages of star formation in molecular clouds.