NOAO/KPNO - NSO,

DEPARTMENT OF ASTRONOMY

AND STEWARD OBSERVATORY

AND NRAO

The University of Arizona

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JOINT COLLOQUIUM

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presents

• DR. KATHRYN A. FLANAGAN

of the

• MIT Center for Space Research

who will present a talk entitled

• "A High-Resolution X-Ray Spectrum of SNR E0102-72: X-Ray Astronomy from Your Armchair"

Abstract: The High Energy Transmission Grating Spectrometer (HETGS) on the Chandra X-ray Observatory is a powerful tool for studying the astrophysical properties of X-ray emitting objects. The HETGS was used to observe an extended source, the supernova remnant E0102-72 in the Small Magellanic Cloud. The dispersed spectrum is analogous to a spectro-heliogram, showing a series of monochromatic images of the source in the light of individual spectral lines. Much can be learned from simple inspection of these images - armchair X-ray astronomy! The X-ray lines enable us to explore plasma conditions in the remnant and estimate the mass of the progenitor star. Systematic differences in the radii of the ring-like images provide compelling evidence for a "reverse shock" propagating through the ejecta. Doppler shifts are apparent in the spectrum, and a two-dimensional Doppler map shows a striking separation of red-shifted and blue-shifted regions. This invites us to consider a three-dimensional model of the SNR.

• on Thursday, October 2, 2003

• at 4:00 p.m.

• in Steward Observatory Lecture Hall-Room N210

Refreshments at 3:30 p.m. in the Lobby