A multi-wavelength study of star formation activity in the S235 complex

Abstract

We have carried out an extensive multi-wavelength study to investigate the star formation process in the S235 complex. The S235 complex has a sphere-like shell appearance at wavelengths longer than 2 $\mu$m and harbors an O9.5V type star approximately at its center. Near-infrared extinction map traces eight subregions (having A${}_V$ $>$ 8 mag), and five of them appear to be distributed in an almost regularly spaced manner along the sphere-like shell surrounding the ionized emission. This picture is also supported by the integrated ${}^{12}$CO and ${}^{13}$CO intensity maps and by Bolocam 1.1 mm continuum emission. The position-velocity analysis of CO reveals an almost semi-ring like structure, suggesting an expanding H\,{\sc ii} region. We find that the Bolocam clump masses increase as we move away from the location of the ionizing star. This correlation is seen only for those clumps which are distributed near the edges of the shell. Photometric analysis reveals 435 young stellar objects (YSOs), 59\% of which are found in clusters. Six subregions (including five located near the edges of the shell) are very well correlated with the dust clumps, CO gas, and YSOs. The average values of Mach numbers derived using NH${}_3$ data for three (East~1, East~2, and Central~E) out of these six subregions are 2.9, 2.3, and 2.9, indicating these subregions are supersonic. The molecular outflows are detected in these three subregions, further confirming the on-going star formation activity. Together, all these results are interpreted as observational evidence of positive feedback of a massive star.

28 pages, 15 figures, 3 tables, Accepted for publication in The Astrophysical Journal

References in corpus (52)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• Toward Understanding Massive Star Formation
• A new calibration of stellar parameters of Galactic O stars
• Color Transformations for the 2MASS Second Incremental Data Release
• The Wavelength Dependence of Interstellar Extinction from 1.25 to 8.0 microns Using GLIMPSE Data
• 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
• The UKIDSS Galactic Plane Survey
• Observations of IC348: The Disk Population at 2-3 Million Years
• The SCUBA Legacy Catalogue: Continuum Objects Detected by SCUBA
• Infrared Extinction Toward Nearby Star-Forming Regions
• The Spatial Distribution of Star Formation in the Solar Neighbourhood: Do all stars form in clusters?
• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• The Bolocam Galactic Plane Survey: Survey Description and Data Reduction
• Triggered massive-star formation on the borders of Galactic HII regions. I. A search for `collect and collapse' candidates
• HII Region Metallicity Distribution in the Milky Way Disk
• IR Dust Bubbles: Probing the Detailed Structure and Young Massive Stellar Populations of Galactic HII Regions
• The Bolocam Galactic Plane Survey IX: Data Release 2 and Outer Galaxy Extension
• A Uniform CO Survey of the Molecular Clouds in Orion and Monoceros
• The Bolocam Galactic Plane Survey. VII. Characterizing the Properties of Massive Star-Forming Regions
• Isolating signatures of major cloud-cloud collisions using position-velocity diagrams
• The Dynamical State of Barnard 68: A Thermally Supported, Pulsating Dark Cloud
• The Bolocam Galactic Plane Survey IV: 1.1 and 0.35 mm Dust Continuum Emission in the Galactic Center Region
• A Bubbling Nearby Molecular Cloud: COMPLETE Shells in Perseus
• Triggered massive-star formation at the border of the HII region Sh 104
• Analysis of Galactic late-type O dwarfs: more constraints on the weak wind problem
• One Dimensional Dynamical Models of the Carina Nebula Bubble
• Isolating signatures of major cloud-cloud collisions II: The lifetimes of broad bridge features
• Ionisation-induced star formation II: External irradiation of a turbulent molecular cloud
• A Spitzer View of Star Formation in the Cygnus X North Complex
• Spitzer observations of the Massive star forming complex S254-S258: structure and evolution
• How to Find Young Massive Cluster Progenitors
• A Millimeter Continuum Survey for Massive Protoclusters in the Outer Galaxy
• Spitzer and Herschel multiwavelength characterization of the dust content of evolved HII regions
• W40 region in the Gould Belt : An embedded cluster and H II region at the junction of filaments
• A CGPS Look at the Spiral Structure of the Outer Milky Way I: Distances and Velocities to Star Forming Regions
• Star formation around the HII region Sh2-235
• A Detailed Study of Spitzer-IRAC Emission in Herbig-Haro Objects (I): Morphology and Flux Ratios of Shocked Emission
• A multiwavelength study of embedded clusters in W5-east, NGC7538, S235, S252 and S254-S258
• Physical environment of massive star-forming region W42
• A `Water Spout' Maser Jet in S235AB-MIR
• A Survey of Extended H${}_2$ Emission from Massive YSOs
• Infrared photometric study of the massive star forming region S235 using Spitzer-IRAC and JHK observations
• The nature of the bright ULX X-2 in NGC3921: a Chandra position and HST candidate counterpart
• A possible sequential star formation in the giant molecular cloud G174+2.5
• The protoplanetary disks in the nearby massive star forming region Cygnus OB2
• Physical conditions in star forming regions around S235
• Triggered star formation around mid-infrared bubbles in G8.14+0.23 H II region
• Ammonia observations of bright-rimmed clouds: establishing a sample of triggered protostars

Cited by in corpus (44)

• A new look at the molecular gas in M42 and M43; possible evidence for cloud-cloud collision which triggered formation of the OB stars in the Orion Nebula Cluster
• Formation of the active star forming region LHA 120-N 44 triggered by tidally-driven colliding HI flows
• FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope (FUGIN) 2: Possible evidence for formation of NGC~6618 cluster in M17 by cloud-cloud collision
• Multi-wavelength study of the star-formation in the S237 H II region
• New insights in the HII region G18.88-0.49: hub-filament system and accreting filaments
• Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde. III. The Orion Molecular Cloud 1
• Observational signatures of cloud-cloud collision in the extended star-forming region S235
• Observational signatures of end-dominated collapse in the S242 filamentary structure
• Star Formation Induced by Cloud-Cloud Collisions and Galactic Giant Molecular Cloud Evolution
• Star Formation Activity in the molecular cloud G35.20$-$0.74: onset of cloud-cloud collision
• Massive core/star formation triggered by cloud-cloud collision: Effect of magnetic field
• A 6.7 GHz Methanol Maser Survey at High Galactic Latitudes
• Star-forming sites IC 446 and IC 447: an outcome of end-dominated collapse of Monoceros R1 filament
• Cloud-Cloud Collision Induced Star Formation in IRAS 18223-1243
• Hub-filament system in IRAS 05480+2545: young stellar cluster and 6.7 GHz methanol maser
• The molecular cloud S242: physical environment and star formation activities
• The Origin of [CII] 158um Emission toward the HII Region Complex S235
• The SOFIA Massive (SOMA) Star Formation Survey. III. From Intermediate- to High-Mass Protostars
• Gas kinematics and star formation in the filamentary molecular cloud G47.06+0.26
• Unveiling the physical conditions in NGC 6910
• The effects of ionization feedback on star formation: A case study of the M16 H II region
• Unveiling molecular clouds toward bipolar HII region G8.14+0.23
• The physical environment around IRAS 17599-2148: infrared dark cloud and bipolar nebula
• The star formation environment of the FU Ori type star V582 Aur
• Molecular gas in high-mass filament WB673
• Magnetic fields and Star Formation around HII regions: The S235 complex
• Ammonia observations towards the Aquila Rift cloud complex
• Investigating inner and large scale physical environments of IRAS 17008-4040 and IRAS 17009-4042 toward l = 345.5 deg, b = 0.3 deg
• Filamentary Structures and Star Formation Activities in the Sites S234, V582, and IRAS 05231+3512
• Massive core/star formation triggered by cloud-cloud collision: II High-speed collisions of magnetized clouds
• Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde V. The massive filament DR21
• Probing the physical conditions and star formation processes in the Galactic HII region S305
• Unraveling the inner substructure of new candidate hub-filament system in the HII region G25.4NW
• Star-forming site RAFGL 5085: Is a perfect candidate of hub-filament system ?
• Evidence of interacting elongated filaments in the star-forming site AFGL 5142
• Cloud-cloud collision and star formation in G013.313+0.193
• NH${}_3$ Observations of the S235 Star Forming Region: Dense Gas in Inter-core Bridges
• The embedded ring-like feature and star formation activities in G35.673-00.847
• Structure and Kinematics of Sh2-138 -- A distant hub-filament system in the outer Galactic plane
• Kronberger 55: A Candidate for End-dominated Collapse Scenario
• Ionized filaments and ongoing physical processes in massive star-forming sites around l = 345.5 degree
• ALMA discovery of a dual dense probably rotating outflow from a massive young stellar object G18.88MME
• Investigating the physical conditions in extended system hosting mid-infrared bubble N14
• Near-Infrared Polarimetry and H${}_2$ emission toward Massive Young Stars: Discovery of a Bipolar Outflow associated to S235 e2s3