Multiwavelength Study of Dark Globule DC 314.8–5.1: Point-source Identification and Diffuse Emission Characterization

Abstract

We present an analysis of multiwavelength observations of the dark globule DC 314.8–5.1, using data from the Gaia optical, Two Micron All Star Survey near-infrared, and Wide-field Infrared Survey Explorer mid-infrared surveys, dedicated imaging with the Spitzer Space Telescope, and X-ray data obtained with the Swift X-Ray Telescope (XRT). The main goal was to identify possible pre-main-sequence stars (PMSs) and young stellar objects (YSOs) associated with the globule. For this, we studied the infrared colors of all point sources within the boundaries of the cloud. After removing sources with nonstellar spectra, we investigated the Gaia parallaxes for the YSO candidates and found that none are physically related to DC 314.8–5.1. In addition, we searched for X-ray emission from PMSs with Swift-XRT, and found no 0.5–10 keV emission down to a luminosity level ≲10 ^31 erg s ^−1 , typical of a PMS with mass ≥2 M _⊙ . Our detailed inspection therefore supports a very young, “prestellar core” evolutionary stage for the cloud. Based on archival Planck and IRAS data, we moreover identify the presence of hot dust, with temperatures ≳100 K, in addition to the dominant dust component at 14 K, originating with the associated reflection nebula.

Keywords

• Interstellar medium
• Molecular clouds
• Young stellar objects
• Pre-main sequence stars
• Infrared astronomy
• X-ray astronomy