Properties of the dense cores and filamentary structures in the Vela C molecular cloud

Abstract

The initial and boundary conditions of the Galactic star formation in molecular clouds are not well understood. In an effort to shed new light on this long-standing problem, we measured properties of dense cores and filamentary structures in the Vela C molecular cloud, observed with Herschel. We applied the getsf extraction method to separate the components of sources and filaments from each other and their backgrounds, before detecting, measuring, and cataloging the structures. The cores and filamentary structures constitute 40% of the total mass of Vela C, most of the material is in the low-density molecular background cloud. We selected 570 reliable cores, of which 149 are the protostellar cores and 421 are the starless cores. Almost 78% of the starless cores were identified with the gravitationally bound prestellar cores. The exponent of the CMF (alpha = 1.35) is identical to that of the Salpeter IMF. We selected 68 filaments with at least one side that appeared not blended with adjacent structures. The filament widths are in the range of 0.15 pc to 0.63 pc, and have a median value of W = 0.3(0.11) pc. The surface densities of filaments are well correlated with their contrasts and linear densities. Within uncertainties of the filament instability criterion, many filaments may well be both supercritical and subcritical. A large fraction of filaments may definitely be considered supercritical, in which are found 94 prestellar cores, 83 protostellar cores, and only 1 unbound starless core. Taking into account the uncertainties, the supercritical filaments contain only prestellar and protostellar cores. Our findings support the idea that there exists a direct relationship between the CMF and IMF and that filaments play a key role in the formation of prestellar cores, which is consistent with the previous Herschel results.

15 pages, 12 figures, 3 tables, accepted for publication in A&A

References in corpus (60)

• Gaia Data Release 2. Summary of the contents and survey properties
• On the variation of the Initial Mass Function
• The SIMBAD astronomical database
• The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
• The Herschel-SPIRE instrument and its in-flight performance
• From filamentary clouds to prestellar cores to the stellar IMF: Initial highlights from the Herschel Gould Belt survey
• The Formation of Massive Stars from Turbulent Cores
• Cold Dark Clouds: The Initial Conditions for Star Formation
• Planck 2013 results. XI. All-sky model of thermal dust emission
• Characterizing interstellar filaments with Herschel in IC5146
• The Formation of a Star Cluster: Predicting the Properties of Stars and Brown Dwarfs
• The persistent cosmic web and its filamentary structure I: Theory and implementation
• Hi-GAL: the Herschel infrared Galactic Plane Survey
• The Density Probability Distribution in Compressible Isothermal Turbulence: Solenoidal versus Compressive Forcing
• The mass function of dense molecular cores and the origin of the IMF
• Probing the evolution of molecular cloud structure: From quiescence to birth
• Stellar, Brown Dwarf, and Multiple Star Properties from Hydrodynamical Simulations of Star Cluster Formation
• Massive star formation: Nurture, not nature
• Massive star formation in 100,000 years from turbulent and pressurized molecular clouds
• Density probability distribution in one-dimensional polytropic gas dynamics
• The initial mass function : from Salpeter 1955 to 2005
• Filamentary Accretion Flows in the Embedded Serpens South Protocluster
• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• On the Density Distribution in Star-forming Interstellar Clouds
• Filamentary structures and compact objects in the Aquila and Polaris clouds observed by Herschel
• The stellar and sub-stellar IMF of simple and composite populations
• Filaments and ridges in Vela C revealed by Herschel: from low-mass to high-mass star-forming sites
• A Compendium of Distances to Molecular Clouds in the Star Formation Handbook
• The spine of the swan: A Herschel study of the DR21 ridge and filaments in Cygnus X
• The initial conditions of isolated star formation - VI. SCUBA mapping of prestellar cores
• Inverse dynamical population synthesis: Constraining the initial conditions of young stellar clusters by studying their binary populations
• Characterizing the properties of nearby molecular filaments observed with Herschel
• Gravity or turbulence? II. Evolving column density PDFs in molecular clouds
• A multi-scale, multi-wavelength source extraction method: getsources
• Source extraction and photometry for the far-infrared and sub-millimeter continuum in the presence of complex backgrounds
• The Mass-Size Relation from Clouds to Cores. II. Solar Neighborhood Clouds
• The unexpectedly large proportion of high-mass star-forming cores in a Galactic mini-starburst
• The structure and stability of molecular cloud cores in external radiation fields
• Dynamic cores in hydrostatic disguise
• A multi-scale filament extraction method: getfilaments
• Formation versus destruction: the evolution of the star cluster population in galaxy mergers
• Probing the evolution of molecular cloud structure II: From chaos to confinement
• BLAST: The Mass Function, Lifetimes, and Properties of Intermediate Mass Cores from a 50 Square Degree Submillimeter Galactic Survey in Vela (l = ~265)
• The Hi-GAL catalogue of dusty filamentary structures in the Galactic Plane
• Multiscale, multiwavelength extraction of sources and filaments using separation of the structural components: getsf
• From diffuse gas to dense molecular cloud cores
• The Herschel view of the on-going star formation in the Vela-C molecular cloud
• Is the Taurus B213 Region a True Filament?: Observations of Multiple Cyanoacetylene Transitions
• The width of Herschel filaments varies with distance
• On the typical width of Herschel filaments
• Do Lognormal Column-Density Distributions in Molecular Clouds Imply Supersonic Turbulence?
• Massive Quiescent Cores in Orion. -- II. Core Mass Function
• Fragmentation of star-forming filaments in the X-shape Nebula of the California molecular cloud
• Physical properties and chemical composition of the cores in the California molecular cloud
• Strong dependence of the physical properties of cores on spatial resolution in observations and simulations
• Dense cores and star formation in the giant molecular cloud Vela~C
• Uncertainties and biases of source masses derived from fits of integrated fluxes or image intensities
• Multicomponent, multiwavelength benchmarks for source- and filament-extraction methods
• $Herschel$ investigation of cores and filamentary structures in the Perseus molecular cloud
• Inaccuracies and biases of the Gaussian size deconvolution for extracted sources and filaments

Cited by in corpus (5)

• ALMA-IMF XVIII: The assembly of a star cluster: Dense N${}_2$H${}^{+}$ (1-0) kinematics in the massive G351.77 protocluster
• Probing the filamentary nature of star formation in the California giant molecular cloud
• Comparison of Herschel and ArTéMiS observations of massive filaments
• Scale-dependent surface and volume density properties of filaments in molecular clouds
• Loose threads: parsec-scale filamentation in the high Galactic latitude molecular clouds MBM 3 and MBM 16