A rotating molecular disk toward IRAS 18162-2048, the exciting source of HH 80-81

Abstract

We present several molecular line emission arcsec and subarcsec observations obtained with the Submillimeter Array (SMA) in the direction of the massive protostar IRAS 18162-2048, the exciting source of HH 80-81. The data clearly indicates the presence of a compact (radius~425-850 AU) SO2 structure, enveloping the more compact (radius~150 AU) 1.4 millimeter dust emission (reported in a previous paper). The emission spatially coincides with the position of the prominent thermal radio jet which terminates at the HH 80-81 and HH 80N Herbig-Haro objects. Furthermore, the molecular emission is elongated in the direction perpendicular to the axis of the thermal radio jet, suggesting a disk-like structure. We derive a total dynamic mass (disk-like structure and protostar) of 11-15 msun. The SO2 spectral line data also allow us to constrain the structure temperature between 120-160 K and the volume density > 2x10^9 cm-3. We also find that such a rotating flattened system could be unstable due to gravitational disturbances. The data from C17O line emission show a dense core within this star-forming region. Additionally, the H2CO and the SO emissions appear clumpy and trace the disk-like structure, a possible interaction between a molecular core and the outflows, and in part, the cavity walls excavated by the thermal radio jet.

13 pages,11 figures. Accepted in the AJ, 07-15-2011

References in corpus (43)

• A computer program for fast non-LTE analysis of interstellar line spectra
• Toward Understanding Massive Star Formation
• The Formation of Massive Stars from Turbulent Cores
• The Submillimeter Array
• On the Formation of Massive Stars
• On the formation of massive stars
• Magnetic Fields in the Formation of Sun-Like Stars
• The Evolution of Outflow-Envelope Interactions in Low-Mass Protostars
• PROSAC: A Submillimeter Array Survey of Low-Mass Protostars. I. Overview of Program: Envelopes, Disks, Outflows and Hot Cores
• A disk of dust and molecular gas around a high-mass protostar
• A Magnetized Jet from a Massive Protostar
• Fragmentation of Massive Protostellar Disks
• The H2CO abundance in the inner warm regions of low mass protostellar envelopes
• A molecular survey of outflow gas: velocity-dependent shock chemistry and the peculiar composition of the EHV gas
• Sulphur chemistry in the envelopes of massive young stars
• Observations on the Formation of Massive Stars by Accretion
• Infall Collapse Solutions in the Inner Limit: Radiation Pressure and its Effects on Star Formation
• IRAS 16293: A "Magnetic" Tale of Two Cores
• From the Convergence of Filaments to Disk-Outflow Accretion: Massive-Star Formation in W33A
• Massive star formation via high accretion rates and early disk-driven outflows
• Shells, jets, and internal working surfaces in the molecular outflow from IRAS 04166+2706
• Water in the envelopes and disks around young high-mass stars
• Orion KL: The hot core that is not a "Hot Core"
• Forming an Early O-type Star Through Gas Accretion?
• A ring/disk/outflow system associated with W51 North: a very massive star in the making
• A Pulsed, Precessing Jet in Cepheus A
• Rotation of the Warm Molecular Gas Surrounding Ultracompact HII Regions
• A Photoevaporating Rotating Disk in the Cepheus A HW2 Star Cluster
• Collisional formation of very massive stars in dense clusters
• The Collimated Jet Source in IRAS 16547-4247: Time Variation, Possible Precession, and Upper Limits to the Proper Motions Along the Jet Axis
• Discovery of Extremely High Velocity "Molecular Bullets" in the HH 80-81 High-Mass Star-Forming Region
• Young starless cores embedded in the magnetically dominated Pipe Nebula
• The Molecular Condensations Ahead of Herbig-Haro Objects. I. Multi-transition Observations of HH 2
• A new intermediate mass protostar in the Cepheus A HW2 region
• A simple algorithm for optimization and model fitting: AGA (asexual genetic algorithm)
• The role of stellar collisions for the formation of massive stars
• Kinematics of a hot massive accretion disk candidate
• The Rotating Molecular Structures and the Ionized Outflow Associated with IRAS 16547-4247
• VLA and BIMA observations toward the exciting source of the massive HH~80-81 outflow
• Millimeter and submillimeter high angular resolution interferometric observations: dust in the heart of IRAS 18162-2048
• The Molecular Condensations Ahead of Herbig-Haro Objects. III. Radiative and dynamical perturbations of the HH 2 condensation
• A Shock-Induced PDR in the HH 80/81 Flow. Far Infrared Spectroscopy
• An observational survey of molecular emission ahead of Herbig-Haro objects

Cited by in corpus (19)

• Radio Jets from Young Stellar Objects
• Turbulence-induced disc formation in strongly magnetised cloud 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
• The Highly Collimated Radio Jet of HH 80-81: Structure and Non-Thermal Emission
• Collapse of turbulent massive cores with ambipolar diffusion and hybrid radiative transfer I. Accretion and multiplicity
• Multiple monopolar outflows driven by massive protostars in IRAS 18162-2048
• Slow ionized wind and rotating disklike system associated with the high-mass young stellar object G345.4938+01.4677
• Modeling the accretion disk around the high-mass protostar GGD 27-MM1
• Centimeter continuum observations of the northern head of the HH 80/81/80N jet: revising the actual dimensions of a parsec scale jet
• The circumestellar disk of the B0 protostar powering the HH 80-81 radio jet
• Disks and outflows in the massive protobinary system W3(OH)TW
• CO multi-line observations of HH 80-81: a two-component molecular outflow associated with the largest protostellar jet in our Galaxy
• Formation and evolution of the water maser outflow event in AFGL 2591 VLA 3-N
• A very young, compact bipolar H${}_2$O maser outflow in the intermediate-mass star-forming LkH$\alpha$ 234 region
• Searching for compact radio sources associated to UCHII regions
• Massive Quiescent Cores in Orion: V. The Physical Structures on Sub-Jeans Scale and the Chemical Properties in Two Extremely Dense Cores
• Erosion of a dense molecular core by a strong outflow from a massive protostar
• VLBI multi-epoch water maser observations toward massive protostars