Yes for both. They are on by default; you don't need to do anything to enable it. Longer answer follows...
DEP is used by default in Ubuntu. This is done via the NX bit if the CPU supports it, or emulated via memory segmentation if the CPU does not support it. For more details, see the non-executable memory feature item.
ASLR is used by default in Ubuntu on any memory segments that can be relocated (stack, libraries, heap, mmap). The only portion of a program that is not relocatable by default is the main code area ("text" segment). Programs need to be specially compiled as PIE (position independent executable) to enable this. Many sensitive programs are already built this way. For more details, see the list
Many additional security features are also available by default in Ubuntu. See the Ubuntu Security Features documentation for the full list.