The JCMT Gould Belt Survey: A First Look at SCUBA-2 Observations of the Lupus I Molecular Cloud

Abstract

This paper presents observations of the Lupus I molecular cloud at 450 and 850 µm with SCUBA-2 as part of the James Clerk Maxwell Telescope Gould Belt Survey (JCMT GBS). Nine compact sources, assumed to be the disks of young stellar objects (YSOs), twelve extended protostellar, pre-stellar and starless cores, and one isolated, low luminosity protostar, are detected in the region. Spectral Energy Distributions (SEDs), including submillimetre fluxes, are produced for 15 YSOs, and each is fitted with the models of Robitaille et al. (2006). The proportion of Class 0 / I protostars is higher than that seen in other Gould Belt regions such as Ophiuchus and Serpens. Circumstellar disk masses are calculated for more evolved sources, while protostellar envelope masses are calculated for protostars. Up to four Very Low Luminosity Objects are found, a large fraction when compared to other Spitzer c2d regions. One YSO has a disk mass greater than the minimum mass solar nebula (MMSN). Twelve starless / protostellar cores are detected by SCUBA-2, and their masses are calculated. The stability of these cores is examined using both the thermal Jeans mass and a turbulent virial mass when possible. Two cores in Lupus I are super-Jeans and contain no known YSOs. One of these cores has a virial parameter of 1.1 ± 0.4, and could therefore be prestellar. The high ratio of Class 0 / I to Class III YSOs (1:1), and the presence of a prestellar core candidate, provides support for the hypothesis that a shock recently triggered star formation in Lupus I.