The Early ALMA View of the FU Ori Outburst System

Abstract

We have obtained ALMA Band 7 observations of the FU Ori outburst system at 0.6"x0.5" resolution to measure the link between the inner disk instability and the outer disk through sub-mm continuum and molecular line observations. Our observations detect continuum emission which can be well modeled by two unresolved sources located at the position of each binary component. The interferometric observations recover the entire flux reported in previous single-dish studies, ruling out the presence of a large envelope. Assuming that the dust is optically thin, we derive disk dust masses of $2\times 10^{-4}$M${}_{\odot }$ and $8\times 10^{-5}$M${}_{\odot }$, for the north and south components respectively. We place limits on the disks' radii of $r<$45 AU. We report the detection of molecular emission from ${}^{12}$CO(3-2), HCO${}^{+}$(4-3) and from HCN(4-3). The ${}^{12}$CO appears widespread across the two binary components, and is slightly more extended than the continuum emission. The denser gas tracer HCO${}^{+}$ peaks close to the position of the southern binary component, while HCN appears peaked at the position of the northern component. This suggests that the southern binary component is embedded in denser molecular material, consistent with previous studies that indicate a heavily reddened object. At this angular resolution any interaction between the two unresolved disk components cannot be disentangled. Higher resolution images are vital to understanding the process of star formation via rapid accretion FU Ori-type episodes.

ApJ Accepted

References in corpus (5)

• The Burst Mode of Protostellar Accretion
• The Hot Inner Disk of FU Ori
• Proplyds and Massive Disks in the Orion Nebula Cluster Imaged with CARMA and SMA
• Mid-infrared size survey of Young Stellar Objects: Description of Keck segment-tilting experiment and basic results
• The Differential Rotation of FU Ori

Cited by in corpus (26)

• Flybys in protoplanetary discs: I. Gas and dust dynamics
• The ALMA early science view of FUor/EXor objects - V: continuum disc masses and sizes
• Resolving the FU Ori System with ALMA: Interacting Twin Disks?
• Chemical Signatures of the FU Ori Outbursts
• Near-Infrared High-Resolution Imaging Polarimetry of FU Ori-Type Objects: Towards A Unified Scheme for Low-Mass Protostellar Evolution
• The ALMA Early Science view of FUor/EXor objects. I. Through the looking-glass of V2775 Ori
• Massive compact disks around FU Orionis-type young eruptive stars revealed by ALMA
• A 1.3 mm SMA Survey of 29 Variable Young Stellar Objects
• The ALMA Early Science View of FUor/EXor objects. II. The Very Wide Outflow Driven by HBC 494
• Millimeter-sized Dust Grains Appear Surviving the Water-sublimating Temperature in the Inner 10 au of the FU Ori Disk
• A concordant scenario to explain FU Ori from deep centimeter and millimeter interferometric observations
• On the rise times in FU Orionis events
• Irregular dust features around intermediate-mass young stars with GPI: signs of youth or misaligned disks?
• Diagnosing 0.1-10 au scale morphology of the FU\,Ori disk using ALMA and VLTI/GRAVITY
• The ALMA Early Science View of FUor/EXor objects. IV. Misaligned Outflows in the Complex Star-forming Environment of V1647 Ori and McNeil's Nebula
• Mass transport from the envelope to the disk of V346 Nor: a case study for the luminosity problem in an FUor-type young eruptive star
• The Circumstellar Disk and Asymmetric outflow of the EX Lup Outburst System
• Interferometric view of the circumstellar envelopes of northern FU Orionis-type stars
• The SPHERE view of three interacting twin disc systems in polarised light
• The disk of FU Orionis viewed with MATISSE/VLTI: first interferometric observations in $L$ and $M$ bands
• ALMA Observations of Young Eruptive Stars: continuum disk sizes and molecular outflows
• An ALMA Study of the FU-Ori Type Object V900 Mon: Implications for the Progenitor
• The Mid-Infrared Evolution of the FU Orionis Disk
• Testing the Binary Trigger Hypothesis in FUors
• An APEX study of molecular outflows in FUor-type stars
• A survey of IRAS young stellar object candidates. Searching for large-scale Herbig-Haro objects