The molecular cloud S242: physical environment and star formation activities

Abstract

We present a multi-wavelength study to probe the star formation (SF) processes on a larger scale (~1.05 deg x 0.56 deg) around the S242 site. The S242 molecular cloud is depicted in a velocity range from -3.25 to 4.55 km/s and has spatially elongated appearance. Based on the virial analysis, the cloud is prone to gravitational collapse. The cloud harbors an elongated filamentary structure (EFS; length ~25 pc) evident in the Herschel column density map and the EFS has an observed mass per unit length of ~200 M_sun/pc exceeding the critical value of ~16 M_sun/pc (at T = 10 K). The EFS contains a chain of Herschel clumps (M_clump ~150 to 1020 M_sun), revealing the evidence of fragmentation along its length. The most massive clumps are observed at both the EFS ends, while the S242 HII region is located at one EFS end. Based on the radio continuum maps at 1.28 and 1.4 GHz, the S242 HII region is ionized by a B0.5V - B0V type star and has a dynamical age of ~0.5 Myr. The photometric 1 - 5 microns data analysis of point-like sources traces young stellar objects (YSOs) toward the EFS and the clusters of YSOs are exclusively found at both the EFS ends, revealing the SF activities. Considering the spatial presence of massive clumps and YSO clusters at both the EFS ends, the observed results are consistent with the prediction of a SF scenario of the end-dominated collapse driven by the higher accelerations of gas.

arXiv comment19 pages, 10 figures, 1 table, Accepted for publication in The Astrophysical Journal

References in corpus (36)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
• The Herschel-SPIRE instrument and its in-flight performance
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• From filamentary clouds to prestellar cores to the stellar IMF: Initial highlights from the Herschel Gould Belt survey
• A Spitzer Survey of Young Stellar Clusters within One Kiloparsec of the Sun: Cluster Core Extraction and Basic Structural Analysis
• MAMBO Mapping of Spitzer c2d Small Clouds and Cores
• High-Mass Proto-Stellar Candidates - II : Density structure from dust continuum and CS emission
• Filamentary structure of star-forming complexes
• Realistic Ionizing Fluxes for Young Stellar Populations from 0.05 to twice solar metallicity
• Infrared Extinction Toward Nearby Star-Forming Regions
• Cluster-formation in the Rosette molecular cloud at the junctions of filaments
• The Spatial Distribution of Star Formation in the Solar Neighbourhood: Do all stars form in clusters?
• The Bolocam Galactic Plane Survey: Survey Description and Data Reduction
• Cooling, Gravity and Geometry: Flow-driven Massive Core Formation
• Collapse and Fragmentation in Finite Sheets
• The earliest phases of star formation - A Herschel key project. The thermal structure of low-mass molecular cloud cores
• Giant Molecular Filaments in the Milky Way
• The Bolocam Galactic Plane Survey IX: Data Release 2 and Outer Galaxy Extension
• ATLASGAL -- A Galaxy-wide sample of dense filamentary structures
• A near IR imaging survey of intermediate and high-mass young stellar outflow candidates
• Characterizing filaments in regions of high-mass star formation: High-resolution submilimeter imaging of the massive star-forming complex NGC 6334 with ArTéMiS
• Aspect Ratio Dependence of the Free-Fall Time for Non-Spherical Symmetries
• Smoothed Particle Hydrodynamics simulations of expanding HII regions. I. Numerical methods and tests
• Modes of Star Formation in Finite Molecular Clouds
• Gravitational fragmentation caught in the act: the filamentary Musca molecular cloud
• Cluster Formation Triggered by Filament Collisions in Serpens South
• A multi-wavelength study of star formation activity in the S235 complex
• Fragmentation in filamentary molecular clouds
• W40 region in the Gould Belt : An embedded cluster and H II region at the junction of filaments
• Physical environment of massive star-forming region W42
• Multi-wavelength study of the star-formation in the S237 H II region
• Study of morphology and stellar content of the Galactic HII region IRAS 16148-5011
• A CO Line and Infrared Continuum Study of the Active Star-Forming Complex W51

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• Lynds Bright Nebulae: Sites of possible twisted filaments and ongoing star formation
• Sequential Star Formation in the filamentary structures of Planck Galactic cold clump G181.84+0.31
• [CII] emission properties of the massive star-forming region RCW36 in a filamentary molecular cloud
• The Distribution of Dense Cores near HII Regions
• Census of young stellar population in the Galactic H II region Sh2-242
• Kronberger 55: A Candidate for End-dominated Collapse Scenario
• Molecular Clouds Associated with {H \small{II}} regions and Candidates within l = 106.65${}^{\circ }$ to 109.50${}^{\circ }$ and b = $-$1.85${}^{\circ }$ to 0.95${}^{\circ }$