Milky Way galaxy
The Milky Way galaxy is the name given by Humans to the galaxy within which they live. The games Star Control 2 and The Ur-Quan Masters therefore take place within a portion of this galaxy.
It is unknown if the analogous HyperSpace galaxy contains the gravity wells of all the stars in the Milky Way galaxy, but it is possible that it does — if we assume that the density of the HyperSpace galaxy is uniform (or at least that the average is close to the density in our region), then even if each of the two Ur-Quan subspecies has circumvented the galaxy once, they wouldn't have needed an average speed greater than 10 standard HyperSpace distance units per day (which is even less than the speed of the Kohr-Ah fleet during the Death March — 15.8 distance units per day). It is also almost certain that the HyperSpace galaxy is larger than than 500-600 millions square HyperSpace distance units.1