Environment and Protostellar Evolution

Abstract

Even today in our Galaxy, stars form from gas cores in a variety of environments, which may affect the properties of resulting star and planetary systems. Here we study the role of pressure, parameterized via ambient clump mass surface density, on protostellar evolution and appearance, focussing on low-mass, Sun-like stars and considering a range of conditions from relatively low pressure filaments in Taurus, to intermediate pressures of cluster-forming clumps like the Orion Nebula Cluster (ONC), to very high pressures that may be found in the densest Infrared Dark Clouds (IRDCs) or in the Galactic Center (GC). We present unified analytic and numerical models for collapse of prestellar cores, accretion disks, protostellar evolution and bipolar outflows, coupled to radiative transfer (RT) calculations and a simple astrochemical model to predict CO gas phase abundances. Prestellar cores in high pressure environments are smaller and denser and thus collapse with higher accretion rates and efficiencies, resulting in higher luminosity protostars with more powerful outflows. The protostellar envelope is heated to warmer temperatures, affecting infrared morphologies (and thus classification) and astrochemical processes like CO depletion to dust grain ice mantles (and thus CO morphologies). These results have general implications for star and planet formation, especially via their effect on astrochemical and dust grain evolution during infall to and through protostellar accretion disks.

7 pages, 5 figures. accepted for publication in ApJL

References in corpus (27)

• The Formation of Massive Stars from Turbulent Cores
• A simple model for the evolution of the dust population in protoplanetary disks
• Interpreting Spectral Energy Distributions from Young Stellar Objects. I. A grid of 200,000 YSO model SEDs
• Competitive accretion in embedded stellar cluster
• Evolution of Massive Protostars with High Accretion Rates
• Efficiencies of Low-Mass Star and Star Cluster Formation
• On the Role of Disks in the Formation of Stellar Systems: A Numerical Parameter Study of Rapid Accretion
• Dense Gas and Star Formation: Characteristics of Cloud Cores Associated with Water Masers
• Evolution of Massive Protostars via Disk Accretion
• The chemical history of molecules in circumstellar disks. I. Ices
• Mid-Infrared Extinction Mapping of Infrared Dark Clouds II. The Structure of Massive Starless Cores and Clumps
• Gravitational Collapse and Star Formation in Logotropic and Non-Isothermal Spheres
• The chemical history of molecules in circumstellar disks. II. Gas-phase species
• Three-Dimensional Radiation Transfer in Young Stellar Objects
• The Different Structures of the Two Classes of Starless Cores
• Bipolar molecular outflows driven by hydromagnetic protostellar winds
• Models for Dense Molecular Cloud Cores
• Effects of magnetic fields on the cosmic-ray ionization of molecular cloud cores
• G0.253+0.016: A centrally condensed, high-mass protocluster
• On the temperature structure of the Galactic Centre cloud G0.253+0.016
• Radiation Transfer of Models of Massive Star Formation. III. The Evolutionary Sequence
• The Dependence of Protostellar Luminosity on Environment in the Cygnus-X Star-Forming Complex
• The Onset of Massive Star Formation: The Evolution of Temperature and Density Structure in an Infrared Dark Cloud
• Radiation Transfer of Models of Massive Star Formation. I. Dependence on Basic Core Properties
• Survival of interstellar molecules to prestellar dense core collapse and early phases of disk formation
• Radiation Transfer of Models of Massive Star Formation. II. Effects of the Outflow
• A Density Dependence for Protostellar Luminosity in Class I Sources: Collaborative Accretion

Cited by in corpus (15)

• Distributed star formation throughout the Galactic Center cloud Sgr B2
• The SOFIA Massive (SOMA) Star Formation Survey. I. Overview and First Results
• The Core Mass Function Across Galactic Environments. II. Infrared Dark Cloud Clumps
• ALMA Cycle 1 Observations of the HH46/47 Molecular Outflow: Structure, Entrainment and Core Impact
• The Core Mass Function in the Massive Protocluster G286.21+0.17 revealed by ALMA
• Radiation Transfer of Models of Massive Star Formation. IV. The Model Grid and Spectral Energy Distribution Fitting
• Massive Star Formation via the Collapse of Subvirial and Virialized Turbulent Massive Cores
• Zooming in to Massive Star Birth
• The Impact of Feedback in Massive Star Formation. II. Lower Star Formation Efficiency at Lower Metallicity
• Continuity of accretion from clumps to Class 0 high-mass protostars in SDC335
• Core Emergence in a Massive Infrared Dark Cloud: A Comparison Between Mid-IR Extinction and 1.3 mm Emission
• GMC Collisions As Triggers of Star Formation. VIII. The Core Mass Function
• The young stellar population of Lynds 1340. An infrared view
• Comparison of Low-Mass and High-Mass Star Formation
• Fire from Ice - Massive Star Birth from Infrared Dark Clouds