CIRCUMBINARY GAS ACCRETION ONTO A CENTRAL BINARY: INFRARED MOLECULAR HYDROGEN EMISSION FROM GG Tau A
- Space Telescope Science Institute, 3700 San Martin Dr. Baltimore, MD 21218 (United States)
- Department of Physics and Astronomy, Colgate University, 13 Oak Drive, Hamilton, NY 13346 (United States)
- Observatoire Aquitain des Sciences de l'Univers (OASU), Universite de Bordeaux, 2 rue de l'Observatoire, BP89, F-33271 Floirac Cedex (France)
- IRAM, 300 Rue de la Piscine, 38406 Saint Martin d'Heres (France)
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States)
We present high spatial resolution maps of ro-vibrational molecular hydrogen emission from the environment of the GG Tau A binary component in the GG Tau quadruple system. The H{sub 2} v = 1-0 S(1) emission is spatially resolved and encompasses the inner binary, with emission detected at locations that should be dynamically cleared on several hundred year timescales. Extensions of H{sub 2} gas emission are seen to {approx}100 AU distances from the central stars. The v = 2-1 S(1) emission at 2.24 {mu}m is also detected at {approx}30 AU from the central stars, with a line ratio of 0.05 {+-} 0.01 with respect to the v = 1-0 S(1) emission. Assuming gas in LTE, this ratio corresponds to an emission environment at {approx}1700 K. We estimate that this temperature is too high for quiescent gas heated by X-ray or UV emission from the central stars. Surprisingly, we find that the brightest region of H{sub 2} emission arises from a spatial location that is exactly coincident with a recently revealed dust 'streamer' which seems to be transferring material from the outer circumbinary ring around GG Tau A into the inner region. As a result, we identify a new excitation mechanism for ro-vibrational H{sub 2} stimulation in the environment of young stars. The H{sub 2} in the GG Tau A system appears to be stimulated by mass accretion infall as material in the circumbinary ring accretes onto the system to replenish the inner circumstellar disks. We postulate that H{sub 2} stimulated by accretion infall could be present in other systems, particularly binaries and 'transition disk' systems which have dust-cleared gaps in their circumstellar environments.
- OSTI ID:
- 22039285
- Journal Information:
- Astrophysical Journal, Vol. 754, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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