[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.