If dark matter is real matter out there in space, it must be absorbing photons from adjacent stars and other bodies. Also, by definition, it is not emitting any radiation, so it must be inexorably heating up. Is this sustainable, or will it cause some sort of explosion or start the body on an emission path later. Or is there some other way in which it could be losing heat ? Another question on this matter. Has anyone established whether dark matter is actually emitting radiation but this is so weak that our detectors cannot “see” the emitting body.