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.
Cite
@article{arxiv.astro-ph/0512230,
title = {Keck Interferometer Observations of FU Orionis Objects},
author = {R. Millan-Gabet and J. D. Monnier and R. L. Akeson and L. Hartmann and J. -P. Berger and A. Tannirkulam and S. Melnikov and R. Billmeier and N. Calvet and P. D'Alessio and L. A. Hillenbrand and M. Kuchner and W. A. Traub and P. G. Tuthill and C. Beichman and A. Boden and A. Booth and M. Colavita and M. Creech-Eakman and J. Gathright and M. Hrynevych and C. Koresko and D. Le Mignant and R. Ligon and B. Mennesson and C. Neyman and A. Sargent and M. Shao and M. Swain and R. Thompson and S. Unwin and G. van Belle and G. Vasisht and P. Wizinowich},
journal= {arXiv preprint arXiv:astro-ph/0512230},
year = {2009}
}
Comments
Accepted by The Astrophysical Journal, in press