Hello,
That is a kernel panic, which can be caused by hardware and/or software issues. I believe that Darwin Kernel Version 9.4.8 is from Mac OS X 10.5.x Leopard. If so, that version of OS X may not be supported by your iMac.
-Which exact model iMac, is it the iMac (27-inch, Mid 2011)? If so, the minimum OS X version it will run is OS X 10.6.6 Snow Leopard and the maximum is macOS 10.13.6 High Sierra.
-Can you explain a bit more about "I select the cd bootable drive."?
-What version of OS X/macOS are you attempting to install and what medium is the installer on?
C