Characterizing star formation activity in infrared dark cloud MSXDC G048.65-00.29

TL;DR

This study uses multi-wavelength infrared data and YSO modeling to characterize star formation activity in the IRDC G48.65, revealing ongoing low to intermediate mass star formation with diverse evolutionary stages.

Contribution

It provides a detailed analysis of YSO populations in IRDC G48.65, demonstrating that star formation is ongoing and not limited to massive stars, using comprehensive spectral energy distribution modeling.

Findings

17 sources analyzed, 13 identified as YSOs

YSOs range from sub-solar to ~8 solar masses

Star formation is active and ongoing in the cloud

Abstract

Infrared Dark Clouds (IRDCs), condensed regions of the ISM with high column densities, low temperatures and high masses, are suspected sites of star formation. Thousands of IRDCs have already been identified. To date, it has not been resolved whether IRDCs always show star formation activity and, if so, if massive star formation (> 8 solar masses) is the rule or the exception in IRDCs. Previous analysis of sub-millimeter cores in the cloud MSXDC G048.65-00.29 (G48.65) indicates embedded star formation activity. To characterize this activity in detail, mid-infrared photometry (3-30 micron) has been obtained with the Spitzer Space Telescope. This paper analyzes the point sources seen in the 24 micron band, combined with counterparts or upper limits at shorter and longer wavelengths. Data points in wavelength bands ranging from 1 up to 850 micron are used to compare each 24 micron source to a set of Spectral Energy Distributions of Young Stellar Object (YSO) models. By assessing the models that fit the data, an attempt is made to identify YSOs as such and determine their evolutionary stages and stellar masses. A total of 17 sources are investigated, 13 of which are classified as YSOs, primarily - but not exclusively - in an early embedded phase of star formation. The modeled masses of the central stellar objects range from sub-solar to ~8 solar masses. Every YSO is at less than 1 pc projected distance from its nearest YSO neighbor. We conclude that IRDC G48.65 is a region of active star formation. We find YSOs in various evolutionary phases, indicating that the star formation in this cloud is not an instantaneous process. The inferred masses of the central objects suggest that this IRDC hosts only low to intermediate mass YSOs and none with masses exceeding ~8 solar masses.