Other
Scientific paper
Jan 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010aas...21533303l&link_type=abstract
American Astronomical Society, AAS Meeting #215, #333.03; Bulletin of the American Astronomical Society, Vol. 42, p.432
Other
Scientific paper
We present results from our Hubble Space Telescope WFPC-2 mosaics (in four filters: [O III], [S II], [O I] and a relatively line-free continuum) of the Crab Nebula. The Crab Nebula comprises the Crab pulsar and surrounding synchrotron emission, a shock driven into the backside of the supernova ejecta by the pulsar wind, and a contact discontinuity interior to this shock where the low-density pulsar wind accelerates into the ejecta. This region contains numerous Rayleigh-Taylor (R-T) instabilities that famously characterize the Crab Nebula. Our observations reveal a notable asymmetry between the northwest (NW) and southeast (SE) ends of the nebula. We attribute this asymmetry to the 120 km/s motion of the pulsar toward the northwest. The pulsar is nearly on and moving along an axis of symmetry we fit to our mosaics. The pulsar motion implies that the pulsar wind-driven shock has propagated farther, and into lower-density ejecta, in the NW quadrant; we predict faster shock speeds and longer post-shock cooling timescales in the NW. Using the models of Sankrit et al. (1997) for post-shock line emission, we infer faster shock speeds in the NW, consistent with expectations. We have adapted the models of Jun et al. (1998), and predict earlier initiation of R-T instabilities in the NW, consistent with our findings of longer and more developed R-T fingers there. Our HST images also reveal a lack of filamentary structure behind the shock in the NW quadrant, which we argue is a manifestation of the lower ejecta densities and longer cooling timescales there. In this dissertation talk I will expand on these and other observations we have made of the perimeter of the Crab Nebula, and our interpretation of the Crab's evolution.
No associations
LandOfFree
HST WFPC2 Observations Of The Crab Nebula: A Northwest-Southeast Asymmetry In Filamentary Properties does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with HST WFPC2 Observations Of The Crab Nebula: A Northwest-Southeast Asymmetry In Filamentary Properties, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and HST WFPC2 Observations Of The Crab Nebula: A Northwest-Southeast Asymmetry In Filamentary Properties will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-962005