VLA and BIMA observations toward the exciting source of the massive HH~80-81 outflow

Abstract

We present high angular resolution VLA and BIMA observations of NH${}_3$, HCO${}^{+}$, HCN and SO molecular emission and 1.4, 3.5 and 7 mm continuum emission toward the exciting source of the HH~80-81 system. This object is one of the few massive protostars known to be driving a collimated outflow. We report the first detection of SO 5${}_5$--4${}_4$ molecular emission toward the exciting source of HH 80-81, suggesting that this transition may be a good tracer of molecular gas near massive protostars. We also detected toward this source dust continuum emission at 1.4 and 3.5 mm. From the SO molecular emission and the dust emission we roughly estimated that the molecular mass associated with the circumstellar surroundings of the exciting source of the thermal jet is in the range 1 -- 3 M${}_{\odot }$. Weak and broad (2,2) ammonia emission was also found in the direction of the jet suggesting the presence of small amounts of molecular gas at high temperatures ($>$ 50 K). The VLA observations show the presence of three ammonia components toward the HH 80-81 region. The brightest component peaks at $\sim 8^{\prime \prime }$ to the NE of the thermal jet and is associated with the H${}_2$O maser spots in the region. A second ammonia clump is located about 25${}^{\prime \prime }$ to the NE of the jet and is associated with class I methanol masers. The third ammonia component is located 1${}^{\prime }$ to the south from the thermal jet and may be a molecular core yet without stellar formation. The BIMA observations show that the strongest emission in the HCO${}^{+}$ and HCN lines originate close to the H${}_2$O maser, and cover the same spatial region and velocity range as the brightest ammonia component.

18 pages, 10 figures. To appear in The Astrophysical Journal

Cited by in corpus (22)

• Gravity or turbulence? -III. Evidence of pure thermal Jeans fragmentation at ~0.1 pc scale
• Spitzer IRAC and MIPS Imaging of Clusters and Outflows in 9 High-mass Star Forming Regions
• Early stages of cluster formation: fragmentation of massive dense cores down to ~1000 AU
• A SCUBA imaging survey of ultracompact HII regions: The environments of massive star formation
• Fragmentation of massive dense cores down to ~1000 AU: Relation between fragmentation and density structure
• Magnetic fields in massive star forming regions
• On the simultaneous evolution of massive protostars and their host cores
• Resolving the polarized dust emission of the disk around the massive star powering the HH~80-81 radio jet
• The VLTI/MIDI survey of massive young stellar objects - Sounding the inner regions around intermediate- and high-mass young stars using mid-infrared interferometry
• Discovery of Extremely High Velocity "Molecular Bullets" in the HH 80-81 High-Mass Star-Forming Region
• Water Masers Toward Ultracompact HII Regions
• Survey of intermediate/high-mass star-forming regions at centimeter and millimeter wavelengths
• Multiple monopolar outflows driven by massive protostars in IRAS 18162-2048
• Modeling the accretion disk around the high-mass protostar GGD 27-MM1
• Millimeter and submillimeter high angular resolution interferometric observations: dust in the heart of IRAS 18162-2048
• Detection of non-thermal emission from the massive protostellar jet HH80-81 at low radio frequencies using GMRT
• A survey of SiO 5-4 emission towards outflows from massive young stellar objects
• A rotating molecular disk toward IRAS 18162-2048, the exciting source of HH 80-81
• The circumestellar disk of the B0 protostar powering the HH 80-81 radio jet
• High-spatial-resolution CN and CS observation of two regions of massive star formation
• Unveiling a cluster of protostellar disks around the massive protostar GGD27 MM1
• Erosion of a dense molecular core by a strong outflow from a massive protostar