Keck Interferometer Observations of FU Orionis Objects

Abstract

We present new K-band long baseline interferometer observations of three young stellar objects of the FU Orionis class, V1057 Cyg, V1515 Cyg and Z CMa-SE, obtained at the Keck Interferometer during its commissioning science period. The interferometer clearly resolves the source of near-infrared emission in all three objects. Using simple geometrical models we derive size scales (0.5-4.5 AU) for this emission. All three objects appear significantly more resolved than expected from simple models of accretion disks tuned to fit the broadband optical and infrared spectro-photometry. We explore variations in the key parameters that are able to lower the predicted visibility amplitudes to the measured levels, and conclude that accretion disks alone do not reproduce the spectral energy distributions and K-band visibilities simultaneously. We conclude that either disk models are inadequate to describe the near-infrared emission, or additional source components are needed. We hypothesize that large scale emission (10s of AU) in the interferometer field of view is responsible for the surprisingly low visibilities. This emission may arise in scattering by large envelopes believed to surround these objects.

Accepted by The Astrophysical Journal, in press

References in corpus (19)

• Unveiling the Inner Disk Structure of T Tauri Stars
• On the Interferometric Sizes of Young Stellar Objects
• Resolved Inner Disks around Herbig Ae/Be Stars
• The near-infrared size-luminosity relations for Herbig Ae/Be disks
• Observations of T Tauri Disks at Sub-AU Radii: Implications for Magnetospheric Accretion and Planet Formation
• High-Resolution Spectroscopy of FUors
• Observations and modeling of the inner disk region of T Tauri stars
• Interferometer Observations of Subparsec-scale Infrared Emission in the Nucleus of NGC 4151
• The photometric evolution of FU Orionis objects: disc instability and wind-envelope interaction
• Keck Interferometer observations of classical and weak line T Tauri stars
• Observations of DG Tauri with the Keck Interferometer
• New insights on the AU-scale circumstellar structure of FU Orionis
• FU Orionis: A Binary Star?
• The Stellar Composition of the Star Formation Region CMa R1 -- III. A new outburst of the Be star component in Z CMa
• Long-term evolution of FU Orionis objects at infrared wavelengths
• Disks and Halos in Pre-Main-Sequence Stars
• Discovery of a Near-Infrared Jet-Like Feature in the Z Canis Majoris System
• Palomar Testbed Interferometer Observations of Young Stellar Objects
• The vertical structure of T Tauri accretion discs IV. Self-irradiation of the disc in the FU Orionis outburst phase

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• The ALMA early science view of FUor/EXor objects - V: continuum disc masses and sizes
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• The 2008 outburst in the young stellar system ZCMa: I. Evidence of an enhanced bipolar wind on the AU-scale
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• FU Orionis disk outburst: evidence for a gravitational instability scenario triggered in a magnetically dead zone
• Reading between the lines: Disk emission, wind, and accretion during the ZCMa NW outburst
• APEX Observations of the CO Envelope around the Young FUor-type Star V883 Ori
• Exploring intermediate (5-40AU) scales around AB Aurigae with the Palomar Fiber Nuller
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• Interferometric science results on young stellar objects