High-Mass Starless Clumps: Dynamical State and Correlation Between Physical Parameters

Abstract

In order to study the initial conditions of massive star formation, we have previously built a sample of 463 high-mass starless clumps (HMSCs) across the inner Galactic plane covered by multiple continuum surveys. Here, we use ${}^{13}$ CO(2-1) line data from the SEDIGISM survey, which covers 78${}^{\circ }$ in longitude ($-60^{\circ }<l<18^{\circ }$, $|b|<0.5^{\circ }$) with 30${}^{\prime \prime }$ resolution, to investigate the global dynamical state of these parsec-scale HMSCs (207 sources with good quality data, mass $10^2\sim 10^5{\mathrm{M}}_{\odot }$, size $0.1\sim 3.6$ pc). We find that most HMSCs are highly turbulent with a median Mach number ${\mathcal{M}}_{\mathcal{S}}\sim$ 8.2, and 44\%$\sim$55\% of them are gravitationally bound (with virial parameter ${\alpha }_{\mathrm{vir}}\lesssim 2$) if no magnetic fields were present. A median magnetic field strength of 0.33$\sim$0.37 mG would be needed to support these bound clumps against collapse, in agreement with previous observations of magnetic fields in massive star formation regions. Luminosity-to-mass ratio, an important tracer for evolutionary stage, is strongly correlated with dust temperature. Magnetic field strength is also correlated with density. The Larson linewidth-size scaling does not hold in HMSCs. This study advances our understanding of global properties of HMSCs, and our high-resolution ALMA observations are on the way to study the resolved properties.

arXiv commentAccepted for publication on ApJ, 20 pages

References in corpus (51)

• The Spitzer Space Telescope Mission
• Theory of Star Formation
• The Formation of Massive Stars from Turbulent Cores
• ATLASGAL - The APEX Telescope Large Area Survey of the Galaxy at 870 microns
• Hi-GAL: the Herschel infrared Galactic Plane Survey
• Competitive accretion in embedded stellar cluster
• High-Mass Star and Massive Cluster Formation in the Milky Way
• The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers
• A Super-Alfvenic Model of Dark Clouds
• Global Hierarchical Collapse In Molecular Clouds. Towards a Comprehensive Scenario
• ATLASGAL --- properties of a complete sample of Galactic clumps
• Low Virial Parameters in Molecular Clouds: Implications for High Mass Star Formation and Magnetic Fields
• The Bolocam Galactic Plane Survey: Survey Description and Data Reduction
• Hierarchical fragmentation and differential star formation in the Galactic "Snake": infrared dark cloud G11.11-0.12
• Dense Gas and Star Formation: Characteristics of Cloud Cores Associated with Water Masers
• Gravity or Turbulence? The velocity dispersion-size relation
• The ATLASGAL survey: a catalog of dust condensations in the Galactic plane
• Ammonia from cold high-mass clumps discovered in the inner Galactic disk by the ATLASGAL survey
• A CS J=5-4 Mapping Survey Towards High-mass Star Forming Cores Associated with Water Masers
• Properties of Hi-GAL clumps in the inner Galaxy]{The Hi-GAL compact source catalogue. I. The physical properties of the clumps in the inner Galaxy ($-71.0^{\circ }<\ell <67.0^{\circ }$)
• Fragmentation of Molecular Clumps and Formation of Protocluster
• Physical vs. Observational Properties of Clouds in Turbulent Molecular Cloud Models
• The Origin of Massive Stars: The Inertial-Inflow Model
• The Dynamics of Massive Starless Cores with ALMA
• Hierarchical Fragmentation and Jet-like Outflows in IRDC G28.34+0.06, a Growing Massive Protostar Cluster
• A Massive Prestellar Clump Hosting no High-Mass Cores
• Six Myths on the Virial Theorem for Interstellar Clouds
• SEDIGISM: Structure, excitation, and dynamics of the inner Galactic interstellar medium
• A Search for Larson-Type Relations in Numerical Simulations of the ISM. Evidence for Non-Constant Column Densities
• The Virial Balance of Clumps and Cores in Molecular Clouds
• Gravity or turbulence? -III. Evidence of pure thermal Jeans fragmentation at ~0.1 pc scale
• The Bolocam Galactic Plane Survey. XIV. Physical Properties of Massive Starless and Star Forming Clumps
• The SEDIGISM survey: first data release and overview of the Galactic structure
• Testing Larson's relationships in massive clumps
• Search for starless clumps in the ATLASGAL survey
• The Green Bank Ammonia Survey: Dense Cores Under Pressure in Orion A
• Investigating the structure and fragmentation of a highly filamentary IRDC
• Protostellar Outflow Heating in a Growing Massive Protocluster
• The SEDIGISM survey: Molecular clouds in the inner Galaxy
• The Bolocam Galactic Plane Survey. X. A Complete Spectroscopic Catalog of Dense Molecular Gas Observed toward 1.1 mm Dust Continuum Sources with 7.5 <= l <= 194 degrees
• Properties of dense cores in clustered massive star-forming regions at high angular resolution
• Massive 70 micron quiet clumps II: non-thermal motions driven by gravity in massive star formation?
• Massive and low-mass protostars in massive "starless" cores
• High-mass Starless Clumps in the inner Galactic Plane: the Sample and Dust Properties
• The relation between 13CO(2-1) line width in molecular clouds and bolometric luminosity of associated IRAS sources
• Remarkable analytic relations among greybody parameters
• The SEDIGISM survey: a search for molecular outflows
• Subsonic islands within a high-mass star-forming IRDC
• Supersonic turbulence in the cold massive core JCMT 18354-0649S
• Fragmentation of the High-mass "Starless'' Core G10.21-0.31: a Coherent Evolutionary Picture for Star Formation
• Magnetic stability of massive star forming clumps in RCW 106