High mass star formation in the infrared dark cloud G11.11-0.12

Abstract

We report detection of moderate to high-mass star formation in an infrared dark cloud (G11.11-0.12) where we discovered class II methanol and water maser emissions at 6.7 GHz and 22.2 GHz, respectively. We also observed the object in ammonia inversion transitions. Strong emission from the (3,3) line indicates a hot (~60 K) compact component associated with the maser emission. The line width of the hot component (4 km/s), as well as the methanol maser detection, are indicative of high mass star formation. To further constrain the physical parameters of the source, we derived the spectral energy distribution (SED) of the dust continuum by analysing data from the 2MASS survey, HIRAS, MSX, the Spitzer Space Telescope, and interferometric 3mm observations. The SED was modelled in a radiative transfer program: a) the stellar luminosity equals 1200 L_sun corresponding to a ZAMS star of 8 M_sun; b) the bulk of the envelope has a temperature of 19 K; c) the mass of the remnant protostellar cloud in an area 8x10^17 cm or 15 arcsec across amounts to 500M_sun, if assuming standard dust of the diffuse medium, and to about 60 M_sun, should the grains be fluffy and have ice mantles; d) the corresponding visual extinction towards the star is a few hundred magnitudes. The near IR data can be explained by scattering from tenuous material above a hypothetical disk. The class II methanol maser lines are spread out in velocity over 11 km/s. To explain the kinematics of the masing spots, we propose that they are located in a Kepler disk at a distance of about 250 AU. The dust temperatures there are around 150 K, high enough to evaporate methanol--containing ice mantles.

10 pages, 6 figures, Accepted for publication in Astronomy & Astrophysics Journal

References in corpus (9)

• Massive Stars: Their Environment and Formation
• From Massive Protostars to a Giant HII Region: Submillimeter Imaging of the Galactic Mini-starburst W43
• CH3OH and H2O masers in high-mass star-forming regions
• Methanol Masers as Tracers of Circumstellar Disks
• Radio-millimetre investigation of galactic infrared dark clouds
• The G11.11-0.12 Infrared-Dark Cloud: Anomalous Dust and a Non-Magnetic Isothermal Model
• Physical conditions in the Protoplanetary Nebula CRL 618 derived from observations of vibrationally excited HCCCN
• Interactions between a Bright YSO and the MSX Infrared-Dark Cloud G79.3+0.3: An Early Stage of Triggered Star Formation?
• Two massive star-forming regions at early evolutionary stages

Cited by in corpus (61)

• Low Virial Parameters in Molecular Clouds: Implications for High Mass Star Formation and Magnetic Fields
• Hierarchical fragmentation and differential star formation in the Galactic "Snake": infrared dark cloud G11.11-0.12
• How Many Infrared Dark Clouds can form Massive Stars and Clusters?
• A Class I and Class II Methanol Maser Survey of Extended Green Objects (EGOs) from the GLIMPSE Survey
• Kinematic Distances to Molecular Clouds identified in the Galactic Ring Survey
• Magnetic Fields in High-Mass Infrared Dark Clouds
• The ALMA Survey of 70 $\mu$m dark High-mass clumps in Early Stages (ASHES). I. Pilot Survey: Clump Fragmentation
• The "Nessie" Nebula: Cluster Formation in a Filamentary Infrared Dark Cloud
• The Simultaneous Formation of Massive Stars and Stellar Clusters
• Probing the initial conditions of high-mass star formation. II. Fragmentation, stability, and chemistry
• The Mass-Size Relation from Clouds to Cores. II. Solar Neighborhood Clouds
• The Bones of the Milky Way
• A Massive Prestellar Clump Hosting no High-Mass Cores
• The seeds of star formation in the filamentary infrared-dark cloud G011.11-0.12
• The Earliest Phases of Star Formation (EPoS): A Herschel Key Program - The precursors to high-mass stars and clusters
• The early stages of star formation in Infrared Dark Clouds: characterizing the core dust properties
• High-fidelity view of the structure and fragmentation of the high-mass, filamentary IRDC G11.11-0.12
• Resolving the fragmentation of high line-mass filaments with ALMA: the integral shaped filament in Orion A
• Exploring molecular complexity with ALMA (EMoCA): Detection of three new hot cores in Sagittarius B2(N)
• NH3 Observations of the Infrared Dark Cloud G28.34+0.06
• Understanding star formation in molecular clouds II. Signatures of gravitational collapse of IRDCs
• The ATLASGAL survey: distribution of cold dust in the Galactic plane. Combination with Planck data
• A Molecular Line Observation toward Massive Clumps Associated with Infrared Dark Clouds
• SMA observations of Infrared Dark Clouds: A tale of two cores
• Detection of Structure in Infrared-Dark Clouds with Spitzer: Characterizing Star Formation in the Molecular Ring
• Weak and Compact Radio Emission in Early High-Mass Star Forming Regions: I. VLA Observations
• Physical properties of Southern infrared dark clouds
• A Water Maser and Ammonia Survey of GLIMPSE Extended Green Objects (EGOs)
• Distribution and characteristics of Infrared Dark Clouds using genetic forward modelling
• Massive and low-mass protostars in massive "starless" cores
• Mass reservoirs surrounding massive infrared dark clouds: A view by near-infrared dust extinction
• Cloud structure of three Galactic infrared dark star-forming regions from combining ground and space based bolometric observations
• Carbon in different phases ([CII], [CI], and CO) in infrared dark clouds: Cloud formation signatures and carbon gas fractions
• SEDIGISM: The kinematics of ATLASGAL filaments
• Deuterium fractionation and the degree of ionisation in massive clumps within infrared dark clouds
• Physical Conditions of the Earliest Phases of Massive Star Formation: Single-Dish and Interferometric Observations of Ammonia and CCS in Infrared Dark Clouds
• SiO Outflow Signatures Toward Massive Young Stellar Objects with Linearly Distributed Methanol Masers
• VLA Observations of the Infrared Dark Cloud G19.30+0.07
• Confirmation of the VeLLO L1148-IRS: Star Formation at very low (Column) Density
• Two Massive, Low-Luminosity Cores Toward Infrared Dark Clouds
• A search for water masers associated with class II methanol masers - I. Longitude range 6 to 20 degrees
• Infrared Dark Cloud Cores in the SCUBA Legacy Catalogue
• Multiple low-turbulence starless cores associated with intermediate- to high-mass star formation
• LABOCA mapping of the infrared dark cloud MSXDC G304.74+01.32
• The molecular distribution of the IRDC G351.77-0.51
• Fragmentation and Kinematics of dense molecular cores in the filamentary infrared-dark cloud G011.11-0.12
• SiO emission as a probe of Cloud-Cloud Collisions in Infrared Dark Clouds
• The ALMA Survey of 70$\mu$m Dark High-mass Clumps in Early Stages (ASHES) III. A Young Molecular Outflow Driven by a Decelerating Jet
• B-fields And dust in interstelLar fiLAments using Dust POLarization (BALLAD-POL): I. The massive filament G11.11-0.12 observed by SOFIA/HAWC+
• Physical and chemical complexity in high-mass star-forming regions with ALMA. I. Overview and evolutionary trends of physical properties
• VLA observations of water masers towards 6.7 GHz methanol maser sources
• High-angular resolution observations of methanol in the infrared dark cloud core G11.11-0.12P1
• Kinematic and Thermal Structure at the onset of high-mass star formation
• Weak and Compact Radio Emission in Early Massive Star Formation Regions: An Ionized Jet Toward G11.11-0.12P1
• The physical conditions in IRDC clumps from Herschel HIFI observations of H2O
• The Role of Magnetic Fields in the Formation of the Filamentary Infrared Dark Cloud G11.11-0.12
• ALMA-IRDC II. First high-angular resolution measurements of the 14N/15N ratio in a large sample of infrared-dark cloud cores
• Spectral-line Survey of the Region of Massive Star Formation W51e1/e2 in the 4 mm Wavelength Range
• The Seahorse Nebula: New views of the filamentary infrared dark cloud G304.74+01.32 from SABOCA, Herschel, and WISE
• Study of young stellar objects and associated filamentary structures in the inner Galaxy
• What did the seahorse swallow? APEX 170 GHz observations of the chemical conditions in the Seahorse infrared dark cloud