R CrA SMM1A: Fragmentation in A Prestellar Core

Abstract

We report the discovery of multiple condensations in the prestellar core candidate SMM1A in the R~CrA cloud, which may represent the earliest phase of core fragmentation observed thus far. The separation between the condensations is between 1000 and 2100 AU, and their masses range from about 0.1 to 0.2 M_sun. We find that the three condensations have extremely low bolometric luminosities (< 0.1 L_sun) and temperatures (< 20 K), indicating that these are young sources that have yet to form protostars. We suggest that these sources were formed through the fragmentation of an elongated prestellar core. Our results, in concert with other observed protostellar binary systems with separations in the scale of 1000 AU, support the scenario that prompt fragmentation in the isothermal collapse phase is an efficient mechanism for wide binary star formation, while the fragmentation in the subsequent adiabatic phase may be an additional mechanism for close (< 100 AU) binary star formation.

13 pages, 3 figures, to be published by ApJ Letters

References in corpus (8)

• Toward understanding the formation of multiple systems - A pilot IRAM-PdBI survey of Class 0 objects
• Formation Scenario for Wide and Close Binary Systems
• L1448 IRS2E: A candidate first hydrostatic core
• OVRO N2H+ Observations of Class 0 Protostars: Constraints on the Formation of Binary Stars
• Coronae in the Coronet: A very deep X-ray look into a stellar nursery
• ATCA and Spitzer Observations of the Binary Protostellar Systems CG30 and BHR71
• Centimeter Imaging of the R Coronae Australis Region
• A dense micro-cluster of Class 0 protostars in NGC 2264 D-MM1

Cited by in corpus (18)

• SMA Observations of Class 0 Protostars: A High-Angular Resolution Survey of Protostellar Binary Systems
• Close companions around young stars
• Feedback Effects on Low-Mass Star Formation
• Exposed Long-lifetime First-core: A New Model of First Cores Based on Radiation Hydrodynamics
• Impact of Protostellar Outflow on Star Formation: Effects of Initial Cloud Mass
• An ALMA Search for Substructure, Fragmentation, and Hidden Protostars in Starless Cores in Chamaeleon I
• The dense cores and filamentary structure of the molecular cloud in Corona Australis. Herschel SPIRE and PACS observations from the Herschel Gould Belt Survey
• ALMA Observations of Starless Core Substructure in Ophiuchus
• Time Monitoring of Radio Jets and Magnetospheres in the Nearby Young Stellar Cluster R Coronae Australis
• A (sub)millimetre study of dense cores in Orion B9
• Strong irradiation of protostellar cores in Corona Australis
• Molecular Clouds in the North American and Pelican Nebulae: Structures
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): Detection of extremely high density compact structure of prestellar cores and multiple substructures within
• An Observed Lack of Substructure in Starless Cores II: Super-Jeans Cores
• Dynamics, CO depletion, and deuterium fractionation of the dense condensations within the fragmented prestellar core Orion B9-SMM 6
• Radiation Hydrodynamics Simulations of Spherical Protostellar Collapse for Very Low Mass Objects
• Linking ice and gas in the Coronet cluster in Corona Australis
• FORCAST imaging of two small nearby Clusters: The Coronet and B59