Simulating star formation in Ophiuchus

Abstract

We have simulated star formation in prestellar cores, using SPH and initial conditions informed by observations of the cores in Ophiuchus. Because the observations are limited to two spatial dimensions plus radial velocity, we cannot infer initial conditions for the collapse of a particular core. However, with a minimum of assumptions (isotropic turbulence with a power-law spectrum, a thermal mix of compressive and solenoidal modes, a critical Bonnor-Ebert density profile) we can generate initial conditions that match, in a statistical sense, the distributions of mass, projected size and aspect ratio, thermal and non-thermal one-dimensional velocity dispersion, observed in Ophiuchus. The time between core-core collisions in Ophiuchus is sufficiently long, that we can simulate single cores evolving is isolation, and therefore we are able to resolve masses well below the opacity limit. We generate an ensemble of 100 cores, and evolve them with no radiative feedback from the stars formed, then with continuous radiative feedback, and finally with episodic radiative feedback. With no feedback the simulations produce too many brown dwarfs, and with continuous feedback too few. With episodic radiative feedback, both the peak of the protostellar mass function (at ~ 0.2 M_sun) and the ratio of H-burning stars to brown dwarfs are consistent with observations. The mass of a star is not strongly related to the mass of the core in which it forms. Low-mass cores (M ~ 0.1 M_sun) tend to collapse into single objects, whereas high-mass cores (1 > M_sun) usually fragment into several objects with a broad mass range.

16 pages, 9 figures. Accepted by MNRAS

References in corpus (22)

• SPLASH: An interactive visualisation tool for Smoothed Particle Hydrodynamics simulations
• Analytical theory for the initial mass function: CO clumps and prestellar cores
• The properties of brown dwarfs and low-mass hydrogen-burning stars formed by disc fragmentation
• The Mass Distribution and Lifetime of Prestellar Cores in Perseus, Serpens, and Ophiuchus
• The Effects of Radiative Transfer on Low-Mass Star Formation
• The Importance of Radiative Feedback for the Stellar Initial Mass Function
• Bolocam Survey for 1.1 mm Dust Continuum Emission in the c2d Legacy Clouds. II. Ophiuchus
• The Nature of the Dense Core Population in the Pipe Nebula: Thermal Cores Under Pressure
• A SCUBA survey of Orion, the low-mass end of the core mass function
• Brown dwarf formation by gravitational fragmentation of massive, extended protostellar discs
• Radiative transfer and the energy equation in SPH simulations of star formation
• Can giant planets form by gravitational fragmentation of discs?
• On the Distance to the Ophiuchus Star-Forming Region
• Radiation Feedback and Fragmentation in Massive Protostellar Cores
• Evidence for a Turnover in the IMF of Low Mass Stars and Sub-stellar Objects: Analysis from an Ensemble of Young Clusters
• Large Area Mapping at 850 Microns. V. Analysis of the Clump Distribution in the Orion A South Molecular Cloud
• Tidally induced brown dwarf and planet formation in circumstellar discs
• The dust temperatures of the prestellar cores in the rho Oph main cloud and in other star forming regions: consequences for the core mass function
• The initial conditions of star formation VIII: an observational study of the Ophiuchus cloud L1688 and implications for the prestellar core mass function
• High Resolution Near-Infrared Spectroscopy of FUors and FUor-like stars
• Oscillations of starless cores
• Star formation in molecular cores III. The effect of the turbulent power spectrum

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