This means that it is possible that most galaxies , including our own Milky Way , have gone through an active stage , appearing as a quasar or some other class of active galaxy that depended on the black hole mass and the accretion rate , and are now quiescent because they lack a supply of matter to feed into their central black holes to generate radiation .
This means that most galaxies , including our own Milky Way , may have gone through an active stage as a quasar or some other class of active galaxy . They are now quiescent because they lack a supply of matter to feed into their central black holes to generate radiation .