An X-ray View of Two Infrared Dark Clouds G034.43+00.24 and G035.39-00.33

Abstract

We present a high spatial resolution Chandra X-ray study of two Infrared Dark Clouds (IRDCs), G034.43+00.24 and G035.39-00.33, which are expected to be in the early phases of star cluster formation. We detect 112 and 209 valid X-ray point sources towards G034.43+00.24 and G035.39-00.33, respectively. We cross-match the X-ray point sources with 2MASS, GLIMPSE and WISE catalogs and find 53% and 59% of the X-ray sources in G034.43+00.24 and in G035.39-00.33 have corresponding infrared counterparts, respectively. These sources are probable members of young massive clusters in formation, and using stellar isochrones we estimate that a population of 1--2 Myr old, intermediate to high mass young stellar objects (YSOs) exist in both IRDCs. Two and ten Class II counterparts to X-ray sources were identified in G034.43+00.24 and in G035.39-00.33, respectively, which are located in or near dark filaments. The X-ray Luminosity Function (XLF) of G035.39-00.33 implies that the total mass consists of up to $\sim 1,700M_{\odot }$ of stars, using the XLF of the well-studied Orion Nebula Cluster as calibrator. This corresponds to a star formation efficiency of at most 5%, indicating the system is still very much gas dominated and in an early stage of the star formation process. The population of G034.43+00.24 is less well determined due to the lower sensitivity of its observations.

Accepted for publication in ApJ. 18 pages, 5 figures, 8 tables. Full tables will be available online as machine readable tables

References in corpus (14)

• The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)
• Magnetic Fields in High-Mass Infrared Dark Clouds
• The dynamical properties of dense filaments in the infrared dark cloud G035.39-00.33
• The young stellar population in M17 revealed by Chandra
• X-ray flares in Orion young stars. I. Flare characteristics
• Diagnostics of stellar flares from X-ray observations: from the decay to the rise phase
• A Chandra Study of the Rosette Star-Forming Complex. I. The Stellar Population and Structure of the Young Open Cluster NGC 2244
• The Structure, Dynamics and Star Formation Rate of the Orion Nebula Cluster
• Investigating the structure and fragmentation of a highly filamentary IRDC
• An X-ray Census of Young Stars in the Massive Southern Star-Forming Complex NGC 6357
• Distributed Low-Mass Star Formation in the IRDC G34.43+00.24
• Temperature structure and kinematics of the IRDC G035.39-00.33
• Similar complex kinematics within two massive, filamentary infrared dark clouds
• GMC Collisions as Triggers of Star Formation. VI. Collision-Induced Turbulence

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• CO Depletion in Infrared Dark Clouds