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

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.

10 pages, 6 figures; v2: minor editorial changes to match published version

References in corpus (21)

• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• Control of star formation by supersonic turbulence
• GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
• Interpreting Spectral Energy Distributions from Young Stellar Objects. II. Fitting observed SEDs using a large grid of pre-computed models
• Interpreting Spectral Energy Distributions from Young Stellar Objects. I. A grid of 200,000 YSO model SEDs
• Absolute Calibration of the Infrared Array Camera on the Spitzer Space Telescope
• 2-D Radiative Transfer in Protostellar Envelopes: I. Effects of Geometry on Class I Sources
• Infrared Dark Clouds: precursors to star clusters
• 2-D Radiative Transfer in Protostellar Envelopes: II. An Evolutionary Sequence
• The Physics of Star Formation
• Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer. I. The Stellar Calibrator Sample and the 24 micron Calibration
• Point Source Extraction with MOPEX
• A Catalog of MSX Infrared Dark Cloud Candidates
• Massive Protostars in the Infrared Dark Cloud MSXDC G034.43+00.24
• The Arecibo Methanol Maser Galactic Plane Survey--I: Data
• Embedded Star Formation in the Eagle Nebula with Spitzer/GLIMPSE
• The Protostar in the massive Infrared Dark Cloud IRDC18223-3
• Initial Conditions for Massive Star Birth -- Infrared Dark Clouds
• The Modelling of InfraRed Dark Clouds
• Physical Characteristics of a Dark Cloud in an Early Stage of Star Formation toward NGC 7538: an Outer Galaxy Infrared Dark Cloud?

Cited by in corpus (7)

• The Earliest Phases of Star Formation (EPoS): A Herschel Key Program - The precursors to high-mass stars and clusters
• Carbon in different phases ([CII], [CI], and CO) in infrared dark clouds: Cloud formation signatures and carbon gas fractions
• Infrared Dark Cloud Cores in the SCUBA Legacy Catalogue
• LABOCA mapping of the infrared dark cloud MSXDC G304.74+01.32
• Star Formation Activity in the Long, Filamentary Infrared Dark Cloud G53.2
• G048.66-0.29: Physical State of an Isolated Site of Massive Star Formation
• Spectroscopic [CI] mapping of the infrared dark cloud G48.65-0.29