Cistus, with its many hybrids and cultivars, is commonly encountered as a garden flower. The common name rockrose is applied to the species, a name also shared by the related genera Halimium, Helianthemum and Tuberaria, all in the family Cistaceae. The common name gum cistus is applied to resin-bearing species, especially C. ladanifer.
Quasars are part of a class of objects known as active galactic nuclei (AGN). Other classes include Seyfert galaxies and blazars. All three require supermassive black holes to power them.
It also says the galaxies we see around us now may have been quasars in the distant past; even our Milky Way galaxy may have been a quasar-like galaxy long ago --- now not much material falls into the large black hole at the Milky Way's center, so the radiation output from the center is not as great as it used to be.hese objects were called the qausi-stellar radio sources, or quasars for short. Later, it was found these sources could not be stars in our galaxy, but must be very far away --- as far as any of the distant galaxies seen.