I have'nt got my copy of the copy of the core rules yet, but I'm wondering where abouts in the imperium is Jericho Reach. Is there a map showing it's location? Or does it explain at all? Just very curious.

Its effectively near Ultramaar, if you have the 40k tabletop book, look for the Hadex anomoly on the map

Thanks for that, I went and checked it out. I actually have'nt looked at the TT book in a while and rediscovered lots of cool fluff. May the emperor light your way.