Probing fragmentation and velocity sub-structure in the massive NGC 6334 filament with ALMA

Abstract

Herschel surveys of Galactic clouds support a paradigm for low-mass star formation in which dense filaments play a crucial role. The detailed fragmentation properties of star-forming filaments remain poorly understood, however, and the validity of the filament paradigm in the high-mass regime is still unclear. To investigate the density/velocity structure of the filament in the high-mass star-forming region NGC6334, we conducted ALMA observations in the 3mm continuum and the N2H+(1-0) line at ~3arcsec resolution. The filament was detected in both tracers. We identified 26 cores at 3mm and 5 velocity-coherent fiber-like features in N2H+ within the filament. The typical length of, and velocity difference between, the fiber-like features of the NGC6334 filament are reminiscent of the properties for the fibers of the low-mass star-forming filament B211/B213. Only 2 or 3 of the 5 velocity-coherent features are well aligned with the filament and may represent genuine, fiber sub-structures. The core mass distribution has a peak at ~10Msun. They can be divided into 7 groups of cores, closely associated with ArTeMiS clumps. The projected separation between cores and the projected spacing between clumps are roughly consistent with the effective Jeans length in the filament and a physical scale of about 4 times the filament width, respectively, suggesting a bimodal filament fragmentation process. Despite being one order of magnitude denser and more massive than the B211/B213 filament, the NGC6334 filament has a similar density/velocity structure. The difference is that the cores in NGC6334 appear to be an order of magnitude denser and more massive than the cores in Taurus. This suggests that dense filaments may evolve and fragment in a similar manner in low- and high-mass star-forming regions, and that the filament paradigm may hold in the intermediate-mass (if not high-mass) star formation regime.

arXiv comment21 pages, 18 figures, accepted for publication in A&A

References in corpus (51)

• From filamentary clouds to prestellar cores to the stellar IMF: Initial highlights from the Herschel Gould Belt survey
• The Star Formation Rate and Dense Molecular Gas in Galaxies
• Clouds, filaments and protostars: the Herschel Hi-GAL Milky Way
• Characterizing interstellar filaments with Herschel in IC5146
• On the Star Formation Rates in Molecular Clouds
• Herschel view of the Taurus B211/3 filament and striations: Evidence of filamentary growth?
• The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers
• Filamentary structure of star-forming complexes
• Cores, filaments, and bundles: hierarchical core formation in the L1495/B213 Taurus region
• Global collapse of molecular clouds as a formation mechanism for the most massive stars
• Variations in the Galactic star formation rate and density thresholds for star formation
• Helical Fields and Filamentary Molecular Clouds
• Star Formation Rates in Molecular Clouds and the Nature of the Extragalactic Scaling Relations
• The Formation and Destruction of Molecular Clouds and Galactic Star Formation
• Filaments and ridges in Vela C revealed by Herschel: from low-mass to high-mass star-forming sites
• An ALMA study of the Orion Integral Filament: I. Evidence for narrow fibers in a massive cloud
• Characterizing the properties of nearby molecular filaments observed with Herschel
• Fragmentation of Molecular Clumps and Formation of Protocluster
• On the nature of star-forming filaments: I. Filament morphologies
• A multi-scale, multi-wavelength source extraction method: getsources
• Chains of dense cores in the Taurus L1495/B213 complex
• Reconstructing the density and temperature structure of prestellar cores from $Herschel$ data: A case study for B68 and L1689B
• Formation and evolution of interstellar filaments; Hints from velocity dispersion measurements
• The dynamical properties of dense filaments in the infrared dark cloud G035.39-00.33
• The identification of filaments on far infrared and submillimiter images. Morphology, physical conditions and relation with star formation of filamentary structure
• A census of dense cores in the Taurus L1495 cloud from the Herschel Gould Belt Survey
• Fibers in the NGC1333 proto-cluster
• Formation of Magnetized Prestellar Cores with Ambipolar Diffusion and Turbulence
• Testing the universality of the star formation efficiency in dense molecular gas
• High-fidelity view of the structure and fragmentation of the high-mass, filamentary IRDC G11.11-0.12
• Filamentary fragmentation in a turbulent medium
• A multi-scale filament extraction method: getfilaments
• Characterizing filaments in regions of high-mass star formation: High-resolution submilimeter imaging of the massive star-forming complex NGC 6334 with ArTéMiS
• Resolving the fragmentation of high line-mass filaments with ALMA: the integral shaped filament in Orion A
• The earliest phases of high-mass star formation, as seen in NGC 6334 by \emph{Herschel}
• Synthetic C${}^{18}$O observations of fibrous filaments: the problems of mapping from PPV to PPP
• Ion-neutral friction and accretion-driven turbulence in self-gravitating filaments
• Hierarchical Fragmentation of the Orion Molecular Filaments
• Probing accretion of ambient cloud material into the Taurus B211/B213 filament
• Dense core properties in the Infrared Dark cloud G14.225-0.506 revealed by ALMA
• The role of molecular filaments in the origin of the prestellar core mass function and stellar initial mass function
• Perturbation growth in accreting filaments
• Star-forming content of the giant molecular filaments in the Milky Way
• Interstellar filaments and star formation
• Two-level hierarchical fragmentation in the Orion Molecular Cloud 1 northern filament
• A Wide-field Near- and Mid-Infrared Census of Young Stars in NGC 6334
• Molecular clouds in the NGC 6334 and NGC 6357 region; Evidence for a 100 pc-scale cloud-cloud collision triggering the Galactic mini-starbursts
• Analytical core mass function (CMF) from filaments: Under which circumstances can filament fragmentation reproduce the CMF?
• Oscillating Filaments: I - Oscillation and Geometrical Fragmentation
• Similar complex kinematics within two massive, filamentary infrared dark clouds
• Background derivation and image flattening: getimages

Cited by in corpus (31)

• Unifying low and high mass star formation through density amplified hubs of filaments
• Properties of the dense core population in Orion B as seen by the Herschel Gould Belt survey
• Dust polarized emission observations of NGC 6334; BISTRO reveals the details of the complex but organized magnetic field structure of the high-mass star-forming hub-filament network
• Multiscale, multiwavelength extraction of sources and filaments using separation of the structural components: getsf
• From diffuse gas to dense molecular cloud cores
• Classification of Filament Formation Mechanisms in Magnetized Molecular Clouds
• The Origin of the Stellar Mass Distribution and Multiplicity
• Fragmentation of star-forming filaments in the X-shape Nebula of the California molecular cloud
• JCMT BISTRO Observations: Magnetic Field Morphology of Bubbles Associated with NGC 6334
• Witnessing the fragmentation of a filament into prestellar cores in Orion B/NGC 2024
• The DR21(OH) Trident -- Resolving the Massive Ridge into Three Entangled Fibers As the Initial Condition of Cluster Formation
• Physical and chemical structure of the Serpens filament -- fast formation and gravity-driven accretion
• Supervised machine learning on Galactic filaments Revealing the filamentary structure of the Galactic interstellar medium
• The Core Mass Function Across Galactic Environments. III. Massive Protoclusters
• Insights on the Sun birth environment in the context of star-cluster formation in hub-filament systems
• Convergent Filaments Contracting Towards an Intermediate-mass Prestellar Core
• The Effect of Shock Wave Duration on Star Formation and the Initial Condition of Massive Cluster Formation
• VLA ammonia observations of L1287: analysis of the "Guitar" core and two filaments
• IC 5146 dark Streamer: is a first reliable candidate of edge collapse, hub-filament systems, and intertwined sub-filaments?
• Emergence of high-mass stars in complex fiber networks (EMERGE) II. The need for data combination in ALMA observations
• Filament Intersections and Cold Dense Cores in Orion A North
• Probing the filamentary nature of star formation in the California giant molecular cloud
• Line emission from filaments in molecular clouds
• Instability and Evolution of Shocked Clouds Formed by Orthogonal Collisions between Magnetized Filamentary Molecular Clouds
• ALMA 0.1 pc View of Molecular Clouds Associated with High-Mass Protostellar Systems in the Small Magellanic Cloud: Are Low-Metallicity Clouds Filamentary or Not?
• ArTéMiS imaging of the filamentary infrared dark clouds G1.75-0.08 and G11.36+0.80: Dust-based physical properties of the clouds and their clumps
• The Milky Way atlas for linear filaments II. clump rotation versus filament orientation
• A High-Mass Young Star-forming Core Escaping from Its Parental Filament
• Comparison of Herschel and ArTéMiS observations of massive filaments
• Investigations of MWISP Filaments. I. Filament Identification and Analysis Algorithms, and Source Catalogue
• Scale-dependent surface and volume density properties of filaments in molecular clouds