HEAD 2000, November 2000
Session 45. Stellar Coronae/Cataclysmic Variables
Oral, Friday, November 10, 2000, 10:10-11:30am, Pago Pago Ballroom

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[45.02] Resolving the Orion Trapezium in X-rays: Lifting the Veil...

N.S. Schulz, C.R. Canizares, D. Huenemoerder (Massachusetts Institute of Technology), J.H. Kastner (Rocheser Institute of Technology), J. Lee, S.C. Taylor (Massachusetts Institute of Technology)

Do you wonder what it would be like to study stars in X-rays without blurry images and with good spectra? We have resolved the Orion Trapezium into X-ray point sources with the the High Energy Transmission Grating Spectrometer (HETGS) onboard the Chandra X-ray Observatory. Within 2'x2' around the Orion Trapezium we detected 111 X-ray sources with luminosities between 6\times 1028 erg cm^{-2} s^{-1} and 2\times 1032 erg cm^{-2} s^{-1}. The two observations separated by 3 weeks reveal a large number of sources which appear variable and heavily absorbed. Some of these also appear in close vicinity to the main Trapezium stars; many are identified with thermal and non-thermal radio sources, as well as with disk-star systems ('proplyds') and we argue that the X-ray emission originates from class I and class II protostars at the cores of the proplyds.

X-ray spectra of the brightest, early type members of the Trapezium reveal a variety of thermal spectra with single soft and hard components or a combination of both with temperatures ranging from kT = 0.67 keV to kT = 3.20 keV. High resolution grating spectra resolved the X-ray emission from the stellar wind of \theta1 Ori C into emission lines and a hot continuum. Detailed diagnostics of these emission lines indicate a highly confined, hot and dense plasma as the source of the X-ray emission.

The author(s) of this abstract have provided an email address for comments about the abstract: nss@space.mit.edu

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