We present high-resolution X-ray spectra of the multiple (hierarchical quadruple) weak-lined T Tauri star system HD 98800, obtained with the High Energy Transmission Grating Spectrograph (HETGS) on board the Chandra X-Ray Observatory. In the zeroth-order Chandra/HETGS X-ray image, both principle binary components of HD 98800 (A and B, separation 0.8") are detected; component A was observed to flare during the observation. The infrared excess (dust disk) component, HD 98800B, is a factor of ~4 fainter in X-rays than the apparently “diskless” HD 98800A in quiescence. The line ratios of He-like species (e.g., Ne ix and O vii) in the HD 98800A spectrum indicate that the X-ray–emitting plasma around HD 98800 is in a typical coronal density regime (log n< ~11 ). We conclude that the dominant X-ray–emitting component(s) of HD 98800 is (are) coronally active. The sharp spectral differences between HD 98800 and the classical T Tauri star TWHya demonstrate the potential utility of high-resolution X-ray spectroscopy in providing diagnostics of pre–main-sequence accretion processes (Refer to PDF file for exact formulas).
Department, Program, or Center
Chester F. Carlson Center for Imaging Science (COS)
Joel H. Kastner et al 2004 ApJ 605 L49
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