This is a kernel panic and will occur when your Mac cannot possibly continue operating, and can be caused by either hardware or software.
The easiest way to determine whether it's a hardware or software problem is to boot into Recovery Mode. Restart your Mac and hold down ⌘ Command +R until the Apple logo appears on screen. If you see the following screen then there's a fair change the problem lies within the software of your Mac. You will probably need to reinstall your OS.

This article has more steps you can go down to help isolate the issue
If you still get the same error when trying to boot into the alternate Recovery OS, that would indicate a problem with the hardware of your Mac. Try removing as many peripherals as you can and reseating the RAM.
In the event of a problem with your hardware, I would recommend you get in touch with an Apple Authorised Service Provider to take a look at your mac, or check out Apple Support