SMA observations of young disks: separating envelope, disk, and stellar masses in class I YSOs

Abstract

(abbreviated) We aim to determine the masses of the envelopes, disks, and central stars of young stellar objects (YSOs) in the Class I stage. We observed the embedded Class I objects IRS 63 and Elias 29 in the rho Ophiuchi star-forming region with the Submillimeter Array (SMA) at 1.1 mm. IRS 63 and Elias 29 are both clearly detected in the continuum, with peak fluxes of 459 resp. 47 mJy/beam. The continuum emission toward Elias 29 is clearly resolved, whereas IRS 63 is consistent with a point source down to a scale of 3 arcsec (400 AU). The SMA data are combined with single-dish data, and disk masses of 0.055 and >= 0.007 MSun and envelope masses of 0.058 and >= 0.058 MSun are empirically determined for IRS 63 and Elias 29, respectively. The disk+envelope systems are modelled with the axisymmetric radiative-transfer code RADMC, yielding disk and envelope masses that differ from the empirical results by factors of a few. HCO+ J = 3-2 is detected toward both sources, HCN J = 3-2 is not. The HCO+ position-velocity diagrams are indicative of Keplerian rotation. For a fiducial inclination of 30 degrees, we find stellar masses of 0.37 +/- 0.13 and 2.5 +/- 0.6 MSun for IRS 63 and Elias 29, respectively. We conclude that the sensitivity and spatial resolution of the SMA at 1.1 mm allow a good separation of the disks around Class I YSOs from their circumstellar envelopes and environments, and the spectral resolution makes it possible to resolve their dynamical structure and estimate the masses of the central stars. The ratios of the envelope and disk masses are found to be 0.2 and 6 for IRS 63 and Elias 29, respectively. This is lower than the values for Class 0 sources, which have Menv/Mdisk >= 10, suggesting that this ratio is a tracer of the evolutionary stage of a YSO.

7 pages, 7 figures, accepted by A&A

References in corpus (26)

• Spectral Energy Distributions of T Tauri Stars With Passive Circumstellar Disks
• The Submillimeter Array
• From Molecular Cores to Planet-forming Disks: A SIRTF Legacy Program
• Flaring vs. self-shadowed disks: the SEDs of Herbig Ae/Be stars
• 2-D Radiative Transfer in Protostellar Envelopes: I. Effects of Geometry on Class I Sources
• Unveiling the Circumstellar Envelope and Disk: A Sub-Arcsecond Survey of Circumstellar Structures
• High Resolution Submillimeter Constraints on Circumstellar Disk Structure
• Radiative Equilibrium and Temperature Correction in Monte Carlo Radiation Transfer
• Infrared Extinction Toward Nearby Star-Forming Regions
• Physical structure and CO abundance of low-mass protostellar envelopes
• Star formation in Perseus - V. Outflows detected by HARP
• PROSAC: A Submillimeter Array Survey of Low-Mass Protostars. I. Overview of Program: Envelopes, Disks, Outflows and Hot Cores
• The COMPLETE Survey of Star-Forming Regions: Phase I Data
• A 3-5 micron VLT spectroscopic survey of embedded young low mass stars I: Structure of the CO ice
• An Extinction Threshold for Protostellar Cores in Ophiuchus
• Optical Spectroscopy of the Surface Population of the rho Ophiuchi Molecular Cloud: The First Wave of Star Formation
• Probing the inner 200 AU of low-mass protostars with the Submillimeter Array: Dust and organic molecules in NGC1333-IRAS2A
• The structure of protostellar envelopes derived from submillimeter continuum images
• Tracing the Mass during Low-Mass Star Formation, IV: Observations and Modeling of the Submillimeter Continuum Emission from Class I Protostars
• A 3-5$\mu$m VLT spectroscopic survey of embedded young low mass stars II; OCN${}^{-}$
• Tracing the envelopes around embedded low-mass young stellar objects with HCO+ and millimeter-continuum observations
• The Environment and Nature of the Class I Protostar Elias 29: Molecular Gas Observations and the Location of Ices
• The structure of the NGC1333-IRAS2 protostellar system on 500 AU scales: an infalling envelope, a circumstellar disk, multiple outflows, and chemistry
• Disk Properties and Density Structure of the Star-Forming Dense Core B335
• An Infrared Multiplicity Survey of Class I/Flat-Spectrum Systems in the Rho Ophiuchi and Serpens Molecular Clouds
• Lensing Properties of Cored Galaxy Models

Cited by in corpus (62)

• Protoplanetary Disks and Their Evolution
• Water in star-forming regions with Herschel (WISH): II. Evolution of 557 GHz 110-101 emission in low-mass protostars
• PROSAC: A Submillimeter Array survey of low-mass protostars. II. The mass evolution of envelopes, disks, and stars from the Class 0 through I stages
• A Keplerian disk around a Class 0 source: ALMA observations of VLA1623A
• Water in star-forming regions (WISH): Physics and chemistry from clouds to disks as probed by Herschel spectroscopy
• A library of near-infrared integral field spectra of young M-L dwarfs
• Signs of Early-Stage Disk Growth Revealed with ALMA
• Evidence for Disk Photoevaporation Driven by the Central Star
• Rotationally-supported disks around Class I sources in Taurus: disk formation constraints
• Grain growth in the envelopes and disks of Class I protostars
• ALMA Observations of the Transition from Infall Motion to Keplerian Rotation around the Late-phase Protostar TMC-1A
• ALMA Observations of Infalling Flows toward the Keplerian Disk around the Class I Protostar L1489 IRS
• The nature of the Class I population in Ophiuchus as revealed through gas and dust mapping
• APEX-CHAMP+ high-J CO observations of low-mass young stellar objects: IV. Mechanical and radiative feedback
• Unveiling the Evolutionary Sequence from Infalling Envelopes to Keplerian Disks around Low-Mass Protostars
• A Keplerian Circumbinary Disk around the Protobinary System L1551 NE
• 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?
• Dust Polarization Toward Embedded Protostars in Ophiuchus with ALMA. III. Survey Overview
• Outflow forces of low mass embedded objects in Ophiuchus: a quantitative comparison of analysis methods
• Unveiling the physical conditions of the youngest disks: A warm embedded disk in L1527
• Transition from the Infalling Envelope to the Keplerian Disk around L1551 IRS 5
• Disk Masses for Embedded Class I Protostars in the Taurus Molecular Cloud
• Angular Momentum Exchange by Gravitational Torques and Infall in the Circumbinary Disk of the Protostellar System L1551 NE
• A Spitzer Five-Band Analysis of the Jupiter-Sized Planet TrES-1
• Active-Region Tilt Angles: Magnetic Versus White-Light Determinations of Joy's Law
• Physical and chemical fingerprint of protostellar disc formation
• ALMA observations of the kinematics and chemistry of disc formation
• Disks and Outflows in CO Rovibrational Emission from Embedded, Low-Mass Young Stellar Objects
• VLA and CARMA Observations of Protostars in the Cepheus Clouds: Sub-arcsecond Proto-Binaries Formed via Disk Fragmentation
• The TEXES Survey For H2 Emission From Protoplanetary Disks
• High-Velocity Jets and Slowly Rotating Envelope in B335
• Apparent disk-mass reduction and planetesimal formation in gravitationally unstable disks in Class 0/I YSOs
• Kinematics and Physical Conditions of the Innermost Envelope in B335
• Observation of rotation in star forming regions: clouds, cores, disks, and jets
• The Mass Accretion Rate and Stellar Properties in Class I Protostars
• Accretion Flows or Outflow Cavities? Uncovering the Gas Dynamics around Lupus 3-MMS
• The Co-evolution of Disk and Star in Embedded Stages: The Case of the Very Low-mass Protostar
• Sub-Keplerian accretion onto circumstellar disks
• Sulfur-Bearing Species Tracing the Disk/Envelope System in the Class I Protostellar Source Elias 29
• The Rotating Outflow, Envelope and Disk in Class-0/I protostar [BHB2007] 11 in the Pipe Nebula
• Classifying the embedded young stellar population in Perseus and Taurus & the LOMASS database
• Interplay between chemistry and dynamics in embedded protostellar disks
• c2d Spitzer IRS spectra of embedded low-mass young stars: gas-phase emission lines
• Missing water in Class I protostellar disks
• ALMA observations of the protostellar disk around the VeLLO IRAS 16253-2429
• Large-scale numerical simulations of star formation put to the test: Comparing synthetic images and actual observations for statistical samples of protostars
• Evolution of CO lines in time-dependent models of protostellar disk formation
• Testing protostellar disk formation models with ALMA observations
• The circumestellar disk of the B0 protostar powering the HH 80-81 radio jet
• Evidence for Infalling Gas of Low Angular Momentum towards the L1551 NE Keplerian Circumbinary Disk
• Interferometric view of the circumstellar envelopes of northern FU Orionis-type stars
• Dynamical structure of the inner 100 AU of the deeply embedded protostar IRAS 16293-2422
• A Rotating Disk in the HH 111 Protostellar System
• Constraint on ion-neutral drift velocity in the Class 0 protostar B335 from ALMA observations
• Characterizing the velocity field in hydrodynamical simulations of low-mass star formation using spectral line profiles
• Computational modeling of the class I low-mass protostar Elias 29 applying optical constants of ices processed by high energy cosmic ray analogs
• FERIA: Flat Envelope Model with Rotation and Infall under Angular Momentum Conservation
• Skewed Distributions and Opposite Velocity Gradients of Submillimeter Molecular Lines in Low-Mass Protostellar Envelopes
• No impact of core-scale magnetic field, turbulence, or velocity gradient on sizes of protostellar disks in Orion A
• Linking High- and Low-Mass Star Formation: Observation-Based Continuum Modelling and Physical Conditions
• The role of external FUV irradiation in the survival of astrophysical ices in Elias 29
• FAUST. XXVIII. High-Resolution ALMA Observations of Class 0/I Disks: Structure, Optical Depths, and Temperatures