[SN, SNR, and Isolated NS -- Oral ]

SNR 1987A: Ten Years of Chandra Monitoring

Sangwook Park, Penn State
David Burrows (Penn State), Judith Racusin (Penn State), Svetozar Zhekov (Colorado), Richard McCray (Colorado), Daniel Dewey (MIT), Vikram Dwarkadas (Chicago), and Gordon Garmire (Penn State)

We have been observing the dynamical and spectral evolution of SNR 1987A with Chandra since 1999. As of 2009 July, we have performed 20 monitoring observations of SNR 1987A. We have also performed 4 deep grating spectroscopic observations. We here review the X-ray evolution of SNR 1987A over the last 10 yr, including updates from the recent observations. The current X-ray emission of SNR 1987A originates primarily from the shock interaction with complex density structures along the inner circumstellar ring, which results in a range of the shock velocities and plasma conditions. We find no evidence for the much-anticipated central point source. The latest data show that SNR 1987A continues to brighten, but probably at a lower rate than 5 yr ago. The radial expansion of the SNR has significantly slowed since ~2004, supporting the interpretation that the blast wave is entering the main body of the inner ring. Recently we transitioned from using the ACIS to using the HETG in our monitoring program. The upcoming X-ray light curves combined with high resolution spectroscopy will help us further study the details of the shock evolution in the context of the density/chemical structures of the equatorial stellar winds and the late-stage evolution history of SN 1987A's massive progenitor.