Millimeter- and Submillimeter-Wave Observations of the OMC-2/3 Region. IV Interaction between the Outflow and the Dense Gas in the Cluster Forming Region of OMC-2 FIR 6

2009/06/04 by Yoshito Shimajiri, Satoko Takahashi, Shigehisa Takakuwa +2
Chemistry · Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Atmospheric Ozone and Climate #Millimeter #Molecular Spectroscopy and Structure #Outflow #Physics #Star formation #Stars #Submillimeter Array #astro-ph.SR

paper · pdf · doi:10.1093/pasj/61.5.1055

14 pages, 7 figures, accepted for publication on PASJ

arxiv created 2009/06/04 · openalex publication_date 2009/10/25 · arxiv updated 2015/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Abstract We have conducted millimeter interferometric observations of the Orion Molecular Cloud-2 (OMC-2) FIR 6 region at an angular resolution of ∼ 4^′′–7^′′ with the Nobeyama Millimeter Array (NMA). In the 3.3-mm continuum emission we detected dusty core counterparts of previously identified FIR sources (FIR 6a, 6b, 6c, and 6d), and moreover resolved FIR 6a into three dusty cores. The size and mass of these cores are estimated to be 1100–5900 AU and 0.19–5.5 M_\odot, respectively. We found that in the ¹²CO (J= 1–0) emission FIR 6b, 6c, and 6d eject molecular outflow, and that the FIR 6c outflow also exhibits at least two collimated jet-like components in SiO (J= 2–1) emission. At the tip of one of the SiO components there appears an abrupt increase in the SiO line width (∼ 15 km s^-1), where the three resolved cores in FIR 6a seem to delineate the tip. These results imply the presence of the interaction and a bowshock front between the FIR 6c molecular outflow and FIR 6a. If the interaction occurred after the formation of the FIR 6a cores, the influence of the FIR 6c outflow on the FIR 6a cores would be minimal, since the total gravitational force in the FIR 6a cores (1.0–7.7 × 10^-4 M_\odot km s^-1yr^-1) is much larger than the outflow momentum flux (2.4 × 10^-5 M_\odot km s^-1yr^-1). On the other hand, it is also possible that the interaction caused the gravitational instability in FIR 6a, and triggered the fragmentation into three cores, since the separation among these cores (∼ 2.0 × 10³ AU) is on the same order of the Jeans length (∼ 5.0–8.4 × 10³ AU). In either case, FIR 6a cores, with a mass of 0.18–1.6 M_\odot and a density of 0.2–5.8 × 10⁷ cm^-3, might be potential formation sites of the next generation of cluster members.

Citations

• Clustered and Triggered Star Formation in W5: Observations withSpitzer
• Arcsecond‐Resolution Submillimeter HCN Imaging of the Binary Protostar IRAS 16293−2422
• High Angular Resolution, Sensitive CSJ= 2–1 andJ= 3–2 Imaging of the Protostar L1551 NE: Evidence for Outflow‐triggered Star Formation?
• SiO J = 5-4 in the HH 211 Protostellar Jet Imaged with the Submillimeter Array
• N2H+ and HC3N Observations of the Orion A Cloud
• Millimeter‐ and Submillimeter‐Wave Observations of the OMC‐2/3 Region. I. Dispersing and Rotating Core around the Intermediate‐Mass Protostar MMS 7
• A Parallactic Distance of \documentclassaastex \usepackageamsbsy \usepackageamsfonts \usepackageamssymb \usepackagebm \usepackagemathrsfs \usepackagepifont \usepackagestmaryrd \usepackagetextcomp \usepackageportland,xspace \usepackageamsmath,amsxtra \usepackage[OT2,OT1]fontenc \newcommand\cyr \renewcommand\rmdefaultwncyr \renewcommand\sfdefaultwncyss \renewcommand\encodingdefaultOT2 \normalfont \selectfont \DeclareTextFontCommand\textcyr\cyr \pagestyleempty \DeclareMathSizes10976 \begindocument \landscape 389⁺²⁴_-21 \enddocument Parsecs to the Orion Nebula Cluster from Very Long Baseline Array Observations