The structure of young embedded protostellar discs

Abstract

Young protostellar discs provide the initial conditions for planet formation. The properties of these discs may be different from those of late-phase (T Tauri) discs due to continuing infall from the envelope and protostellar variability resulting from irregular gas accretion. We use a set of hydrodynamic simulations to determine the structure of discs forming in collapsing molecular clouds. We examine how radiative feedback from the host protostar affects the disc properties by examining three regimes: without radiative feedback, with continuous radiative feedback and with episodic feedback, similar to FU Ori-type outbursts. We find that the radial surface density and temperature profiles vary significantly as the disc accretes gas from the infalling envelope. These profiles are sensitive to the presence of spiral structure, induced by gravitational instabilities, and the radiative feedback provided by the protostar, especially in the case when the feedback is episodic. We also investigate whether mass estimates from position-velocity (PV) diagrams are accurate for early-phase discs. We find that the protostellar system mass (i.e. the mass of the protostar and its disc) is underestimated by up to 20%, due to the impact of an enhanced radial pressure gradient on the gas. The mass of early-phase discs is a significant fraction of the mass of the protostar, so position-velocity diagrams cannot accurately provide the mass of the protostar alone. The enhanced radial pressure gradient expected in young discs may lead to an increased rate of dust depletion due to gas drag, and therefore to a reduced dust-to-gas ratio.

Accepted for publication in MNRAS, 15 Pages, 12 Figures, 2 Tables

References in corpus (24)

• Astrophysics Source Code Library
• SPLASH: An interactive visualisation tool for Smoothed Particle Hydrodynamics simulations
• Protoplanetary Disk Structures in Ophiuchus
• The properties of brown dwarfs and low-mass hydrogen-burning stars formed by disc fragmentation
• Spiral Density Waves in a Young Protoplanetary Disk
• The Effects of Radiative Transfer on Low-Mass Star Formation
• The Importance of Radiative Feedback for the Stellar Initial Mass Function
• A Triple Protostar System Formed via Fragmentation of a Gravitationally Unstable Disk
• Variable protostellar accretion with episodic bursts
• Formation of a Keplerian disk in the infalling envelope around L1527 IRS: transformation from infalling motions to Kepler motions
• Dust retention in protoplanetary disks
• 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
• Formation Scenario for Wide and Close Binary Systems
• Testing the theory of grain growth and fragmentation by millimeter observations of protoplanetary disks
• A Sub-arcsecond Survey Toward Class 0 Protostars in Perseus: Searching for Signatures of Protostellar Disks
• HOPS 383: An Outbursting Class 0 Protostar in Orion
• Observations of Infalling and Rotational Motions on a 1,000-AU Scale around 17 Class 0 and 0/I Protostars: Hints of Disk Growth and Magnetic Braking?
• On the reliability of protostellar disc mass measurements and the existence of fragmenting discs
• Effects of radiation transfer on the structure of self-gravitating disks, their fragmentation and evolution of the fragments
• Vertical Structure of the Transition Zone from Infalling Rotating Envelope to Disk in the Class 0 Protostar, IRAS04368+2557
• The effect of radiative feedback on disc fragmentation
• Constraining the Earliest Circumstellar Disks and their Envelopes
• Gravitational instabilities in a protosolar-like disc II: continuum emission and mass estimates

Cited by in corpus (2)

• Planet formation around M dwarfs via disc instability: Fragmentation conditions and protoplanet properties
• Observational signatures of outbursting protostars -- II: Exploring a wide range of eruptive protostars