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 Phenomenae

Abstract

We have obtained 48 high resolution echelle spectra of the pre-main sequence eclipsing binary system KH~15D (V582 Mon, P = 48.37 d, $e$ $\sim$ 0.6, M${}_A$ = 0.6 M${}_{\odot }$, M${}_B$ = 0.7 M${}_{\odot }$). The eclipses are caused by a circumbinary disk 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 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 circumbinary disk with gas flows as predicted by the models of eccentric T Tauri binaries put forward by Artymowicz & Lubow, Günther & 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.

accepted to ApJ

References in corpus (6)

• Periodic accretion from a circumbinary disk in the young binary UZ Tau E
• The Orbit and Occultations of KH 15D
• Modelling Circumbinary Gas Flows in Close T Tauri Binaries
• Dynamical Masses for Pre-Main Sequence Stars: A Preliminary Physical Orbit for V773 Tau A
• Reflected Light from Sand Grains in the Terrestrial Zone of a Protoplanetary Disk
• The Light Curve of the Weakly-Accreting T Tauri Binary KH 15D from 2005-10: Insights into the Nature of its Protoplanetary Disk

Cited by in corpus (13)

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• Locating the Trailing Edge of the Circumbinary Ring in the KH 15D System
• Another deep dimming of the classical T Tauri star RW Aur A
• Tests of the planetary hypothesis for PTFO 8-8695b
• XMM-Newton monitoring of the close pre-main-sequence binary AK Sco. Evidence of tide driven filling of the inner gap in the circumbinary disk
• The Gaia-ESO Survey: Catalogue of H$\alpha$ emission stars
• Searching for spectroscopic binaries within transition disk objects
• A "blue ring nebula" surrounding a thousands of years old stellar merger
• Optical and Radio Observations of the T Tauri Binary KH 15D (V582 Mon): Stellar Properties, Disk Mass Limit and Discovery of a CO Outflow
• Multi-Wavelength Photometry of the T Tauri Binary V582 Mon (KH 15D): A New Epoch of Occultations
• H-alpha Variability in PTFO8-8695 and the Possible Direct Detection of Emission from a 2 Million Year Old Evaporating Hot Jupiter
• Seeing Through the Ring: Near-Infrared Photometry of V582 Mon (KH 15D)
• Double-peaked OI profile: a likely signature of the gaseous ring around KH 15D