Gamma Ray Bursters vs Quasars?

aguycalledwil

Okay, so this may be a little bit of a trivial question, but I've read conflicting information and found myself confused as a result.

I've read from several sources (wikipedia, books) that GRB's are the most luminous events known to occur in our universe.

However, I've also read that Quasars are 'the most energetic and luminous objects in the known universe' (the physics book - Cllifford A. Pickover).

So my question is, which is brighter? Nowhere that I've found on the net addresses the question. Some sites favour GRB's and others favour quasars, but nowhere compares them. Does anybody have any quantitive values?

Thanks in advance!

Whovian

I'm probably remembering incorrectly, but aren't GRBs caused by Quasars, or at least we think so(?)

aguycalledwil

Not as far as I know.. I thought GRBs were short-lived bursts of gamma radiation as a result of a star's collapse into an ordinary black hole, which occur frequently all over the universe, whilst a quasar is an ancient supermassive black hole that emits intense radio waves. It's to my understanding that quasars were only present early on in the universe's history, which isn't true for GRBs? Maybe I'm mistaken..

Steely Dan

This is basically correct. The problem that the OP cites is mainly one of terminology. In terms of amount of energy released per second, GRBs are undoubtedly the most luminous events in the universe during the brief time over which they occur. Quasars, on the other hand, are the most luminous "static" sources of energy (I use quotation marks because quasars do show rapid variability).

aguycalledwil

Thanks very much, that makes sense to me! It's been bugging me for ages now, glad to get that cleared up. Thanks!