Simulations of star formation in Ophiuchus, II: Multiplicity

Abstract

Lomax et al. have constructed an ensemble of 60 prestellar cores having masses, sizes, projected shapes, temperatures and non-thermal radial velocity dispersions that match, statistically, the cores in Ophiuchus; and have simulated the evolution of these cores using SPH. Each core has been evolved once with no radiative feedback from stars, once with continuous radiative feedback, and once with episodic radiative feedback. Here we analyse the multiplicity statistics from these simulations. With episodic radiative feedback, (i) the multiplicity frequency is ~60% higher than in the field; (ii) the multiplicity frequency and the mean semi-major axis both increase with primary mass; (iii) one third of multiple systems are hierarchical systems with more than two components; (iv) in these hierarchical systems the inner pairings typically have separations of a few au and mass ratios concentrated towards unity, whereas the outer pairings have separations of order 100 au and a flatter distribution of mass ratios. The binary statistics are compatible with observations of young embedded populations, and -- if wider orbits are disrupted preferentially by external perturbations -- with observations of mature field populations. With no radiative feedback, the results are similar to those from simulations with episodic feedback. With continuous radiative feedback, brown dwarfs are under-produced, the number of multiple systems is too low, and the statistical properties of multiple systems are at variance with observation. This suggests that star formation in Ophiuchus may only be representative of global star formation if accretion onto protostars, and hence radiative feedback, is episodic.

References in corpus (62)

• On the variation of the Initial Mass Function
• A Survey of Stellar Families: Multiplicity of Solar-Type Stars
• Stellar Multiplicity
• The Galactic disk mass function: reconciliation of the HST and nearby determinations
• Stellar, brown dwarf and multiple star properties from a radiation hydrodynamical simulation of star cluster formation
• The Solar Neighborhood XVII: Parallax Results from the CTIOPI 0.9m Program -- Twenty New Members of the RECONS 10 Parsec Sample
• Stellar, Brown Dwarf, and Multiple Star Properties from Hydrodynamical Simulations of Star Cluster Formation
• Massive star formation: Nurture, not nature
• Efficiencies of Low-Mass Star and Star Cluster Formation
• A Catalog of Multiplicity among Bright Stellar Systems
• The properties of brown dwarfs and low-mass hydrogen-burning stars formed by disc fragmentation
• The initial mass function : from Salpeter 1955 to 2005
• The Effects of Radiative Transfer on Low-Mass Star Formation
• The Formation of Close Binary Systems by Dynamical Interactions and Orbital Decay
• Mapping the Shores of the Brown Dwarf Desert II: Multiple Star Formation in Taurus-Auriga
• The Importance of Radiative Feedback for the Stellar Initial Mass Function
• The Formation of Low-Mass Binary Star Systems Via Turbulent Fragmentation
• Non-steady Accretion in Protostars
• The Nature of the Dense Core Population in the Pipe Nebula: Thermal Cores Under Pressure
• The initial conditions of isolated star formation - VI. SCUBA mapping of prestellar cores
• The AstraLux Large M-dwarf Multiplicity Survey
• The dynamical evolution of fractal star clusters: the survival of substructure
• The initial conditions of star formation in the Ophiuchus main cloud: Kinematics of the protocluster condensations
• Comparative statistics and origin of triple and quadruple stars
• Long-term Evolution of Protostellar and Protoplanetary Disks. II. Layered Accretion with Infall
• The minimum mass for star formation, and the origin of binary brown dwarfs
• Radiative transfer and the energy equation in SPH simulations of star formation
• Reconstructing the density and temperature structure of prestellar cores from $Herschel$ data: A case study for B68 and L1689B
• Long-term Evolution of Protostellar and Protoplanetary Disks. I. Outbursts
• Simulating star formation in molecular cores II. The effects of different levels of turbulence
• A Multiplicity Survey of the Rho Ophiuchi Molecular Clouds
• Star Cluster Formation in Turbulent, Magnetized Dense Clumps with Radiative and Outflow Feedback
• On the properties of young multiple stars
• Radiation Feedback and Fragmentation in Massive Protostellar Cores
• Radiation Feedback, Fragmentation, and the Environmental Dependence of the Initial Mass Function
• The statistical properties of stars and their dependence on metallicity: the effects of opacity
• The importance of episodic accretion for low-mass star formation
• A systematic survey for eruptive young stellar objects using mid-infrared photometry
• Evidence for a Turnover in the IMF of Low Mass Stars and Sub-stellar Objects: Analysis from an Ensemble of Young Clusters
• Do binaries in clusters form in the same way as in the field?
• The dependence of star formation on initial conditions and molecular cloud structure
• Clumps and triggered star formation in ionised molecular clouds
• SEREN - A new SPH code for star and planet formation simulations
• Importance of the Initial Conditions for Star Formation - III: Statistical Properties of Embedded Protostellar Clusters
• Importance of the Initial Conditions for Star Formation - II. Fragmentation Induced Starvation and Accretion Shielding
• Structure of Protostellar Collapse Candidate B335 Derived from Near-Infrared Extinction Maps
• Testing the universality of star formation - I. Multiplicity in nearby star-forming regions
• Episodic accretion, protostellar radiative feedback, and their role in low-mass star formation
• Multiple Star Formation to the Bottom of the IMF
• Dynamical population synthesis: Constructing the stellar single and binary contents of galactic field populations
• An improved sink particle algorithm for SPH simulations
• Protostellar disks formed from rigidly rotating cores
• Fragmentation and Evolution of Molecular Clouds. II: The Effect of Dust Heating
• Protostellar discs formed from turbulent cores
• Testing the universality of star formation - II. Comparing separation distributions of nearby star-forming regions and the field
• The binary companion mass ratio distribution: an imprint of the star formation process?
• Simulating star formation in Ophiuchus
• Star formation in molecular cores III. The effect of the turbulent power spectrum
• Binary mass ratios: system mass not primary mass
• Mapping the core mass function onto the stellar IMF: multiplicity matters
• The intrinsic shapes of starless cores in Ophiuchus
• Interactions between brown-dwarf binaries and Sun-like stars

Cited by in corpus (30)

• Discovery of an equal-mass "twin" binary population reaching 1000+ AU separations
• Star Cluster Formation in a Turbulent Molecular Cloud Self-Regulated by Photo-Ionisation Feedback
• The properties of discs around planets and brown dwarfs as evidence for disc fragmentation
• The Necessity of Feedback Physics in Setting the Peak of the Initial Mass Function
• Zooming in on Individual Star Formation: Low- and High-mass Stars
• Formation of wide binary stars from adjacent cores
• ALMA Observations of Starless Core Substructure in Ophiuchus
• Is stellar multiplicity universal? Tight stellar binaries in the Orion Nebula Cluster
• The effect of radiative feedback on disc fragmentation
• IN-SYNC VI. Identification and Radial Velocity Extraction for 100+ Double-Lined Spectroscopic Binaries in the APOGEE/IN-SYNC Fields
• The dynamical evolution of low-mass hydrogen-burning stars, brown dwarfs and planetary-mass objects formed through disc fragmentation
• Forming isolated brown dwarfs by turbulent fragmentation
• On the effects of solenoidal and compressive turbulence in prestellar cores
• On the emergent System Mass Function: the contest between accretion and fragmentation
• Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): A close low mass companion to ET Cha
• Resolved Gaia Triples
• Sink particle radiative feedback in smoothed particle hydrodynamics models of star formation
• Evolution of Hubble wedges in episodic protostellar outflows
• The impact of episodic outflow feedback on stellar multiplicity and the star formation efficiency
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): How do dense core properties affect the multiplicity of protostars?
• The long-term dynamical evolution of disc-fragmented multiple systems in the Solar Neighborhood
• The dependence of stellar properties on initial cloud density
• SPAMCART: a code for smoothed particle Monte Carlo radiative transfer
• Using binary statistics in Taurus-Auriga to distinguish between brown dwarf formation processes
• An ALMA search for substructure and fragmentation in starless cores in Orion B North
• Protostellar Outflows: a window to the past
• The Role of Discs in the Collapse and Fragmentation of Prestellar Cores
• Synthetic observations of protostellar multiple systems
• A theoretical perspective on the formation and fragmentation of protostellar discs
• Unraveling the Spectral Energy Distributions of Clustered YSOs