The PS3 version has been available on Sony's streaming service in the past, allowing for play on modern consoles.
only for games that were actually released for the platform (ISO/CSO formats). If you'd like, I can help you: Sonic Unleashed Psp Rom
In short: Every "Sonic Unleashed PSP ROM" is a fan-made port or mod, not an official Sega release. The PS3 version has been available on Sony's