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Title: COMPLEX VARIABILITY OF THE H{alpha} EMISSION LINE PROFILE OF THE T TAURI BINARY SYSTEM KH 15D: THE INFLUENCE OF ORBITAL PHASE, OCCULTATION BY THE CIRCUMBINARY DISK, AND ACCRETION PHENOMENA

Journal Article · · Astrophysical Journal
 [1];  [2];  [3];  [4]
  1. Department of Physics and Astronomy, Dickinson College, Carlisle, PA 17013 (United States)
  2. Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States)
  3. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)
  4. Astronomy Department, Wesleyan University, Middletown, CT 06459 (United States)

We have obtained 48 high-resolution echelle spectra of the pre-main-sequence eclipsing binary system KH 15D (V582 Mon, P = 48.37 days, e {approx} 0.6, M{sub A} = 0.6 M{sub Sun }, M{sub B} = 0.7 M{sub Sun }). The eclipses are caused by a circumbinary disk (CBD) seen nearly edge on, which at the epoch of these observations completely obscured the orbit of star B and a large portion of the orbit of star A. The spectra were obtained over five contiguous observing seasons from 2001/2002 to 2005/2006 while star A was fully visible, fully occulted, and during several ingress and egress events. The H{alpha} line profile shows dramatic changes in these time series data over timescales ranging from days to years. A fraction of the variations are due to 'edge effects' and depend only on the height of star A above or below the razor sharp edge of the occulting disk. Other observed variations depend on the orbital phase: the H{alpha} emission line profile changes from an inverse P-Cygni-type profile during ingress to an enhanced double-peaked profile, with both a blue and a red emission component, during egress. Each of these interpreted variations are complicated by the fact that there is also a chaotic, irregular component present in these profiles. We find that the complex data set can be largely understood in the context of accretion onto the stars from a CBD with gas flows as predicted by the models of eccentric T Tauri binaries put forward by Artymowicz and Lubow, Guenther and Kley, and de Val-Borro et al. In particular, our data provide strong support for the pulsed accretion phenomenon, in which enhanced accretion occurs during and after perihelion passage.

OSTI ID:
22037153
Journal Information:
Astrophysical Journal, Vol. 751, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English