Study of the Earliest Stages of Galactic Star Formation: BLAST Survey of the Vela Molecular Ridge.

Abstract

Stars form from the gravitational collapse of dense clouds of gas and dust in the interstellar molecular medium. However, little is known about the origin and evolution of these early stages of star formation. In this work, we present a detailed multi-wavelength characterization of a sample of these dense cores detected by the Balloon-borne Large-Aperture Submillimeter Telescope (BLAST) in the Vela-D molecular cloud. Combining the BLAST photometry at 250, 350, and 500 ¹m with addi- tional existing observations from millimeter to mid-infrared wavelengths, we have constrained the spectral energy distribution of 141 cores. Their physical parameters have been estimated assuming an isothermal modi¯ed blackbody model. In addition, associations of BLAST cores with mid-infrared sources allow us to separate starless from proto-stellar cores. We find that proto-stellar cores are characterized by higher luminosities and temperatures than starless cores, indicating an evolutionary sequence.