Mass and luminosity evolution of young stellar objects

Abstract

A model of protostar mass and luminosity evolution in clusters gives new estimates of cluster age, protostar birthrate, accretion rate and mean accretion time. The model assumes constant protostar birthrate, core-clump accretion, and equally likely accretion stopping. Its parameters are set to reproduce the initial mass function, and to match protostar luminosity distributions in nearby star-forming regions. It obtains cluster ages and birthrates from the observed numbers of protostars and pre-main sequence (PMS) stars, and from the modal value of the protostar luminosity. In 31 embedded clusters and complexes the global cluster age is 1-3 Myr, matching available estimates based on optical spectroscopy and evolutionary tracks. This method of age estimation is simpler than optical spectroscopy, and is more useful for young embedded clusters where optical spectrocopy is not possible. In the youngest clusters, the protostar fraction decreases outward from the densest gas, indicating that the local star-forming age increases outward from a few 0.1 Myr in small protostar-dominated zones to a few Myr in large PMS-dominated zones.

To appear in The Astrophysical Journal, Part 1

References in corpus (22)

• Cold Dark Clouds: The Initial Conditions for Star Formation
• A Spitzer Survey of Young Stellar Clusters within One Kiloparsec of the Sun: Cluster Core Extraction and Basic Structural Analysis
• Stellar, brown dwarf and multiple star properties from a radiation hydrodynamical simulation of star cluster formation
• Filamentary structure of star-forming complexes
• The Effects of Radiative Transfer on Low-Mass Star Formation
• The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud
• The Disk Population of the Chamaeleon I Star-Forming Region
• Resolving the Luminosity Problem in Low-Mass Star Formation
• The Global Evolution of Giant Molecular Clouds. I: Model Formulation and Quasi-Equilibrium Behavior
• A Spitzer census of the IC 348 nebula
• Clustered and Triggered Star Formation in W5: Observations with Spitzer
• Current Star Formation in the Ophiuchus and Perseus Molecular Clouds: Constraints and Comparisons from Unbiased Submillimeter and Mid-Infrared Surveys. II
• The Spitzer Gould Belt Survey of Large Nearby Interstellar Clouds: Discovery of a Dense Embedded Cluster in the Serpens-Aquila Rift
• Quantitative Evidence for an Intrinsic Age Spread in the Orion Nebula Cluster
• Star Formation in Space and Time: The Orion Nebula Cluster
• A Multi-Color Optical Survey of the Orion Nebula Cluster. Part I: the Catalog
• Protostar Mass Due to Infall and Dispersal
• Clustered Star Formation in Magnetic Clouds: Properties of Dense Cores Formed in Outflow-Driven Turbulence
• Star formation in dense clusters
• The Structure of the Star-forming Cluster RCW 38
• Spitzer, Near-Infrared, and Submillimeter Imaging of the Relatively Sparse Young Cluster, Lynds 988e
• Cluster Formation in Contracting Molecular Clouds

Cited by in corpus (30)

• The Big Problems in Star Formation: the Star Formation Rate, Stellar Clustering, and the Initial Mass Function
• The Physics of Star Cluster Formation and Evolution
• Continuum Variability of Deeply Embedded Protostars as a Probe of Envelope Structure
• Infall-Driven Protostellar Accretion and the Solution to the Luminosity Problem
• The Luminosities of Protostars in the Spitzer c2d and Gould Belt Legacy Clouds
• How do stars gain their mass? A JCMT/SCUBA-2 Transient Survey of Protostars in Nearby Star Forming Regions
• Core-Halo Age Gradients and Star Formation in the Orion Nebula and NGC~2024 Young Stellar Clusters
• A WISE Census of Young Stellar Objects in Canis Major
• The Spatial Structure of Young Stellar Clusters. III. Physical Properties and Evolutionary States
• Star formation in W3 - AFGL333: Young stellar content, properties and roles of external feedback
• Protostellar half-life: new methodology and estimates
• A Spitzer View of Mon OB1 East/NGC 2264
• Near-infrared Variability among YSOs in the Star Formation Region Cygnus OB7
• The Progression of Star Formation in the Rosette Molecular Cloud
• The relation between accretion rates and the initial mass function in hydrodynamical simulations of star formation
• The accretion history of high-mass stars: An ArTéMiS pilot study of Infrared Dark Clouds
• Protostellar accretion traced with chemistry: Comparing synthetic C18O maps of embedded protostars to real observations
• Protostar mass functions in young clusters
• Origin of the dense core mass function in contracting filaments
• Recurrent strong outbursts of an EXor-like young eruptive star Gaia20eae
• The star formation law in Galactic high-mass star-forming molecular clouds
• Star Formation Activity in the Long, Filamentary Infrared Dark Cloud G53.2
• On the Nature of the High-Energy Rollover in 1H 0419-577
• Virial Clumps in Central Molecular Zone Clouds
• Catalogue of High Protostellar Surface Density Regions in Nearby Embedded Clusters
• On the mass function of stars growing in a flocculent medium
• Probing the Global Dust Properties and Cluster Formation Potential of the Giant Molecular Cloud G148.24+00.41
• The young stellar population of Lynds 1340. An infrared view
• Structured velocity field in the inner envelope of B335: ALMA observations of rare CO isotopologues
• Unraveling the Spectral Energy Distributions of Clustered YSOs