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Optical spectroscopy of Z Canis Majoris, V1057 Cygni, and FU Orionis - Accretion disks and signatures of disk windsHigh resolution, high SNR optical spectra have been used to investigate the hypothesis that in outburst, FU Ori objects are self-luminous accretion disks whose light dominates at optical and near-IR wavelengths. Strong evidence has been found for linewidth versus wavelength correlation in good agreement with model predictions for Z CMa and V1057 Cyg, but not for FU Ori itself. Linewidth varies continuously with wavelength at optical wavelengths in the former two objects, In the case of FU Ori, it is argued that a combination of strong wind components to spectral lines, and surface gravity possibly being lower than that of supergiants, conceals the underlying linewidth versus wavelength relationship. A marginal correlation is found between linewidth and lower excitation potential in all three objects. Synthetic disk spectra are subtracted from observed spectral, and remarkably good fits are found for all three objects for wavelengths longer than about 5000 A.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Welty, Alan D. (Pennsylvania State Univ. University Park, United States)
Strom, Stephen E. (Massachusetts Univ. Amherst, United States)
Edwards, Suzan (Smith College Northampton, MA, United States)
Kenyon, Scott J. (NASA Headquarters Washington, DC United States)
Hartmann, Lee W. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Date Acquired
August 15, 2013
Publication Date
September 20, 1992
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 397
Issue: 1
ISSN: 0004-637X
Subject Category
Distribution Limits