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C. Tam (McGill), M. S. E. Roberts (McGill/MIT), V. M. Kaspi, C. L. Brogan (McGill)
Recent results of radio analysis are presented on the composite supernova remnant G11.2-0.3. We describe updated results from detailed expansion measurements of the remnant's bright, circular shell by comparing archival VLA radio data taken in 1984-85 with recent observations made in 2001-02, which indicate an expansion rate of ~0.5%. The aim is to constrain the age of the remnant based on different possible expansion processes, and to compare it to the conflicting timescales provided by the characteristic age of its associated pulsar PSR J1811-1925 (located directly at the remnant's center), and the age since the historical supernova event of 386 AD, the likely source of this remnant. Futhermore, these expansion measurements in conjunction with detailed Chandra X-ray spectral results allow us to estimate the distance to the remnant, based on its shock characteristics. We also present preliminary images between 90 and 3.5 cm, which can be used to better constrain the broad-band radio spectrum of the shell and pulsar wind nebula.
This work is supported in part by NASA, NSERC and NRAO.
Bulletin of the American Astronomical Society,
© 2003. The American Astronomical Soceity.