Perhaps you should take a look at your alert log.
I pulled this from the alert log of one of my databases.

Code:
PMON started with pid=2, OS id=2230
PSP0 started with pid=3, OS id=2232
MMAN started with pid=4, OS id=2234
DBW0 started with pid=5, OS id=2236
LGWR started with pid=6, OS id=2238
CKPT started with pid=7, OS id=2240
SMON started with pid=8, OS id=2242
RECO started with pid=9, OS id=2244
CJQ0 started with pid=10, OS id=2246
MMON started with pid=11, OS id=2248
MMNL started with pid=12, OS id=2250