those are pretty normal these days...
They are from a kiddie or a bot on a hacked server that trying a lot of user and password to get access to your server...
If you have a complex password, i wouldn't be scared about them...
Also, disable root login ( if not already done... if you need help with this, i believe support can help you to be sure everything is done properly )
You can also change the ssh port... that will solve the scans for sure ...
