Does anyone happen to know the average density of dark matter per unit volume in the milky way? I've seen at least one formula, but I'm not sure I fully comprehend it. Here is the equation I found: ρ0 = 4.5 × 10−2(r0/kpc) − (2/3)2x10^30kg pc−3 The only part of this equation that I can't quite follow is the term "r0." I imagine that must be some unit of mass to make the units work out, but not sure what unit of mass it would be. Anyone happen to know? Also, since dark matter density isn't uniform, do researchers know yet whether it increases around relatively small gravitational bodies, such as the sun, earth, the local group, etc? If so, is there a rough formula for the density of dark matter surrounding a gravitational body or cluster of bodies of a given mass?