A submillimeter view of star formation near the HII region KR 140

We present the results of 450 and 850 mum continuum mapping of the H II region KR 140 using the Submillimeter Common-User Bolometer Array (SCUBA) instrument on the James Clerk Maxwell Telescope (JCMT). KR 140 is a small (5.7 pc diameter) H II region at a distance of 2.3 +/- 0.3 kpc. Five of the six IRAS point sources near KR 140 were mapped in this study. Our analysis shows that two of these IRAS sources are embedded late B-type stars lying well outside the H II region, two are a part of the dust shell surrounding the H II region, and one is the combined emission from an ensemble of smaller sources unresolved by IRAS. We have discovered a number of relatively cold submillimeter sources not visible in the IRAS data, ranging in size from 0.2 to 0.7 pc and in mass from 0.5 to 130 M.. The distribution of masses for all sources is well characterized by a power law N(>M) proportional to M(-alpha) with alpha = 0.5 +/- 0.04, in agreement with the typical mass function for clumped structures of this scale in molecular clouds. Several of the submillimeter sources are found at the H II molecular gas interface and have probably been formed as the result of the expansion of the H II region. Many of the submillimeter sources we detect are gravitationally bound and most of these follow a mass-size relationship expected for objects in virial equilibrium with nonthermal pressure support. Upon the loss of nonthermal support, they could be sites of star formation. Along with the two B stars that we have identified as possible cluster members along with VES 735, we argue that five nearby highly reddened stars are in a pre-main-sequence stage of evolution.