I mentioned that quasars and other active galactic nuclei are thought to be powered by supermassive black holes (SMBH). Let’s consider one aspect of…

I mentioned that quasars and other active galactic nuclei are thought to be poweredby supermassive black holes (SMBH). Let’s consider one aspect of this idea.(a) A typical quasar luminosity is about 10^12 L, where L = 3.83*10^33 erg s^-1 is the luminosity of the Sun. If the energy is released by mass falling into a SMBH,estimate the mass accretion rate. (Convenient units are solar masses per year.)(b) If the mass accretion rate is roughly constant, how long would it take to builda mass of 10^8M , were M is solar mass= 1.989 × 10^33 g? Is that long or short compared with the age of the Universe(about 14 Gyr)? Comment on whether the idea that quasars are powered by accretion onto SMBH makes sense or not.