The Age, Stellar Content and Star Formation Timescale of the B59 Dense Core

Abstract

We have used moderate resolution, near-infrared spectra from the SpeX spectrograph on the NASA Infrared Telescope facility to characterize the stellar content of Barnard 59 (B59), the most active star-forming core in the Pipe Nebula. Measuring luminosity and temperature sensitive features in the spectra of 20 candidate YSOs, we identified likely background giant stars and measured each star's spectral type, extinction, and NIR continuum excess. We find that B59 is composed of late type (K4-M6) low-mass (0.9--0.1 M_sun) YSOs whose median stellar age is comparable to, if not slightly older than, that of YSOs within the Rho Oph, Taurus, and Chameleon star forming regions. Deriving absolute age estimates from pre-main sequence models computed by D'Antona et al., and accounting only for statistical uncertainties, we measure B59's median stellar age to be 2.6+/-0.8 Myrs. Including potential systematic effects increases the error budget for B59's median (DM98) stellar age to 2.6+4.1/-2.6 Myrs. We also find that the relative age orderings implied by pre-main sequence evolutionary tracks depend on the range of stellar masses sampled, as model isochrones possess significantly different mass dependencies. The maximum likelihood median stellar age we measure for B59, and the region's observed gas properties, suggest that the B59 dense core has been stable against global collapse for roughly 6 dynamical timescales, and is actively forming stars with a star formation efficiency per dynamical time of ~6%. This maximum likelihood value agrees well with recent star formation simulations that incorporate various forms of support against collapse, such as sub-critical magnetic fields, outflows, and radiative feedback from protostellar heating. [abridged]

20 pages, 12 figures, accepted for publication in the Astrophysical Journal; updated to amend acknowledgments

References in corpus (26)

• Stellar SEDs from 0.3-2.5 Microns: Tracing the Stellar Locus and Searching for Color Outliers in SDSS and 2MASS
• Radiation-Hydrodynamic Simulations of Collapse and Fragmentation in Massive Protostellar Cores
• The Effects of Radiative Transfer on Low-Mass Star Formation
• The Stellar Population of the Chamaeleon I Star-Forming Region
• The Nature of the Dense Core Population in the Pipe Nebula: Thermal Cores Under Pressure
• 2MASS wide field extinction maps - I. The Pipe nebula
• Equilibrium Star Cluster Formation
• Magnetic Fields in Dark Cloud Cores: Arecibo OH Zeeman Observations
• Characterizing Young Brown Dwarfs using Low Resolution Near-IR Spectra
• Magnetically Regulated Star Formation in 3D: The Case of Taurus Molecular Cloud Complex
• Lithium Depletion of Nearby Young Stellar Associations
• A Survey for New Members of Taurus with the Spitzer Space Telescope
• Driven and Decaying Turbulence Simulations of Low-Mass Star Formation: From Clumps to Cores to Protostars
• Optical polarimetry toward the Pipe nebula: Revealing the importance of the magnetic field
• The Luminosity and Mass Functions of Low-Mass Stars in the Galactic Disk: I. The Calibration Region
• Infrared Spectroscopy and Analysis of Brown Dwarf and Planetary Mass Objects in the Orion Nebula Cluster
• The nature of the dense core population in the Pipe Nebula: A survey of NH3, CCS, and HC5N molecular line emission
• The Spitzer c2d Survey of Nearby Dense Cores: IV. Revealing the Embedded Cluster in B59
• The structure of molecular clouds and the universality of the clump mass function
• The nature of the dense core population in the pipe nebula: core and cloud kinematics from C18O observations
• On the Evolution of the Dense Core Mass Function
• An assessment of Li abundances in weak-lined and classical T Tauri stars of the Taurus-Auriga association
• On the fidelity of the core mass functions derived from dust column density data
• Nothing to hide: An X-ray survey for young stellar objects in the Pipe Nebula
• Diverse protostellar evolutionary states in the young cluster AFGL961
• 2MASS J17112318-2724315: A Deeply-Embedded Low-Mass Protostellar System in the B59 Molecular Cloud

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