XMM-Newton observations across the Cygnus Loop from the northeastern rim to the southwestern rim
Abstract
XMM-Newton observed the Cygnus Loop from the northeastern rim to the southwestern rim by seven pointings We report here the results of the observation The image between 0 3 keV and 3 keV showed a rim-brightened structure which is consistent with the image obtained with ROSAT We extracted spectra from annular regions at intervals of 3 arc-minutes from the center of the Cygnus Loop We can clearly see the prominent emission lines from O VII O VIII Fe-L Ne IX Mg XI Si XIII and S XV at any regions We measured the equivalent width of those emission lines from each region finding that those of O VII O VIII Ne IX and Mg XI showed the largest value at the rim and a gradual decrease toward the center of the Cygnus Loop 1000-500 eV for O VII 550-200 eV for O VIII 130-50 eV for Ne IX and 170-20 eV for Mg XI from the rim to the center respectively On the other hand the equivalent width of Fe-L Si XIII around the center portion clearly shows higher value than those at the rim 200-400 eV for Fe-L 500-2000 eV for Si XIII from the rim to the center respectively These facts suggest that the heavy elements like Si and Fe are not well mixed with the elements in the outer layers and still sitting in the center portion at present Furthermore we found that the radial profile of the equivalent width of Fe-L clearly shows an asymmetric structure the southwestern portion shows higher value This fact suggests asymmetric explosion
- Publication:
-
36th COSPAR Scientific Assembly
- Pub Date:
- 2006
- Bibcode:
- 2006cosp...36.2619K