The direction of outflows from filaments : constraints on core formation

Abstract

Context: It is generally presumed that the outflows from a YSO are directed close to its rotation axis (i.e. along its angular momentum vector and orthogonal to any attendant accretion disc). Many YSOs are formed from dense prestellar cores embedded in filaments, and therefore the relative orientations of outflows and filaments may place useful constraints on the dynamics of core formation. Aims: We explore this possibility, from the viewpoint of what it may tell us about the angular momentum delivered to a core forming in a filament. We stress that we are not here addressing the issue of the relationship of filaments and outflows to the prevailing magnetic field direction, although this is evidently also an interesting issue. Results: Using the limited data available, and neglecting any possible selection effects or correlations between nearby outflows, we infer that the observed outflows have a tendency to be orthogonal to the filaments that contain their driving sources. Specfically, in the cases where the directions of the filaments and outflows are well defined, we infer statistically that 72% of outflows are within $45^{\mathrm{o}}$ of being orthogonal to the filament, and only 28% are within $45^{\mathrm{o}}$ of being parallel to the filament. Conclusions: This suggests that the prestellar cores which spawned the YSOs driving the observed outflows had angular momenta which were approximately orthogonal to the filaments out of which the cores formed. We briefly discuss the implications of this for two proposed core formation mechanisms.

6 pages, 4 figures and 1 table

References in corpus (13)

• The mass function of dense molecular cores and the origin of the IMF
• The SCUBA Legacy Catalogue: Continuum Objects Detected by SCUBA
• A SCUBA survey of Orion, the low-mass end of the core mass function
• Dynamics of Dense Cores in the Perseus Molecular Cloud
• Massive star formation via high accretion rates and early disk-driven outflows
• Large Area Mapping at 850 Microns. V. Analysis of the Clump Distribution in the Orion A South Molecular Cloud
• Supersonic turbulence, filamentary accretion,and the rapid assembly of massive stars and disks
• SCUBA and Spitzer observations of the Taurus molecular cloud - pulling the bull's tail
• Three-dimensional Simulation of Magnetized Cloud Fragmentation Induced by Nonlinear Flows and Ambipolar Diffusion
• The initial conditions of isolated star formation - VII. Spitzer mapping of pre-stellar cores
• The nature of the dense core population in the pipe nebula: core and cloud kinematics from C18O observations
• Formation and Collapse of Nonaxisymmetric Protostellar Cores in Planar Magnetic Interstellar Clouds: Formulation of the Problem and Linear Analysis
• Three-dimensional simulations of molecular cloud fragmentation regulated by magnetic fields and ambipolar diffusion

Cited by in corpus (17)

• YSOVAR: the first sensitive, wide-area, mid-IR photometric monitoring of the ONC
• Turbulent Driving Scales in Molecular Clouds
• A census of molecular hydrogen outflows and their sources along the Orion A molecular ridge: characteristics and overall distribution
• Alignment Between Protostellar Outflows and Filamentary Structure
• UWISH2 -- The UKIRT Widefield Infrared Survey for H2
• Outflow forces of low mass embedded objects in Ophiuchus: a quantitative comparison of analysis methods
• Evidence of high-mass star formation through multi-scale mass accretion in hub-filament-system clouds
• Protostellar discs formed from turbulent cores
• ALMA observations reveal no preferred outflow--filament and outflow--magnetic field orientations
• YSO jets in the Galactic Plane from UWISH2: I - MHO catalogue for Serpens and Aquila
• Anisotropic AGN Outflows and Enrichment of the Intergalactic Medium
• The CARMA-NRO Orion Survey: Protostellar Outflows, Energetics, and Filamentary Alignment
• Molecular hydrogen jets and outflows in the Serpens south filamentary cloud
• The dynamically young outflow of the Class 0 protostar Cha-MMS1
• Independent Core Rotation in Massive Filaments in Orion
• Core formation via filament fragmentation and the impact of ambient pressure on it
• The Milky Way atlas for linear filaments II. clump rotation versus filament orientation