Sup /tg/, quick question.

Does the Immaterium exist outside the Galaxy? Since it's fueled by the emotions and thoughts of sentient beings, it would seem it only really exists where there are sentient beings. Since intergalactic space probably doesn't have those, is it even possible for someone to traverse the Warp out of the Galaxy?

I'm sure it exists in other galaxies, but would it be a burbling little creek in intergalactic space compared to the raging storm it is within the Galaxy?