<LI><A NAME="tex2html1" HREF="node3.html#63">Deep <I>ROSAT</I> HRI soft (0.2- 2 keV band)
X-ray image of Tycho's SNR. Solid (dashed) contours show regions of 
increased (decreased) flux when this image is compared to one taken
4.5 years earlier. The contour levels are in units of  <IMG WIDTH=9 HEIGHT=7 ALIGN=BOTTOM ALT="tex2html_wrap_inline119" SRC="img1.gif"  >  and 
the ones shown correspond to values of -4, -3, 3, 4, 5, and 6.</A>
<LI><A NAME="tex2html2" HREF="node3.html#65">Expansion of Tycho's SNR in the X-ray, optical, and radio
   bands. The rate corresponding to the Sedov expansion law (<I>n</I>=0.4)
   is shown as the horizontal dashed line. The X-ray points at
    <IMG WIDTH=28 HEIGHT=13 ALIGN=BOTTOM ALT="tex2html_wrap_inline127" SRC="img2.gif"  >  and  <IMG WIDTH=28 HEIGHT=13 ALIGN=BOTTOM ALT="tex2html_wrap_inline129" SRC="img3.gif"  >  include the location of the bright
   knots in the southeastern quadrant of Tycho. Note that these points
   are consistent with undecelerated motion (a value of 0.24%
   yr <IMG WIDTH=15 HEIGHT=8 ALIGN=BOTTOM ALT="tex2html_wrap_inline131" SRC="img4.gif"  > ).</A>
