Can quasars reactivate within an established galaxy?

Matt Todd

Is a quasar a one off phenomenon at the inception of a galaxy, or does a super massive black hole produce quasars repeatedly as a by-product when there is too much matter to be absorbed.

Drakkith

I believe it generally only happens early on, but if something causes a significant amount of matter to fall into an unstable orbit then I see no reason why it can't "reactivate".

Matt Todd

Thanks Drakkith. I wonder then if the collision of the Milky Way and Andromeda would create this scenario.

Drakkith

I guess we just have to wait 4 billion years to find out!

Matt Todd

I'll put the kettle on.

TheTechNoir

To my knowledge almost all, if not all quasar's we have observed thus far have been in vastly distant (and so yes, old newly forming galaxies) so I am inclined to think that if the milky way/andromeda merger had the potential to have a realistic chance of producing a quasar then we would observe more, closer by/newer quasars from other galatic mergers?

EDIT: Though I agree with Drakkith, I can't see why it couldn't happen again if there were a source of enough infalling matter. Don't know of any mechanism or interaction that could cause this though as we don't have any evidence of this ever happening I don't think?

Chalnoth

Quasars definitely turn on when galaxies form, but are also believed to turn on when galaxies merge.

TheTechNoir

Is that a prediction or has there been any observational evidence to lend credence to the belief? And what about in more recent times cosmologically speaking? It wouldn't surprise me I guess if it were mergers taking place in the young universe.

Thanks for the response dude. I am curious about this, 'cause I don't believe any quasars have been found that are anywhere close to recent, so it puzzles me why if mergers like milky-andromeda could form a quasar in today's universe why then are the only observed quasars from many billions of years ago?



Okay, doing a little searching I found this. http://laserstars.org/news/3C405.html Any one know if this story is legitimate? Or have reliable citations for this? I haven't had time yet to read the article, but saw the distance is just over half a billion LY away. I'm curious to learn more about (if it isn't covered in the article) whether this is thought to be as a result of a merger, and if so, what if any properties of the merging galaxies is or could in prinicipal be known.

But from a quick search it seems like there are some more recent quasars than I had thought, so perhaps there really is a chance milky-andromeda could cause one as well. Interesting stuff

Chalnoth

I honestly don't know enough about galaxy evolution to say for sure. However, I would say that the observation of jets of matter coming from the center of our own Milky Way demonstrate that its black hole has been active in the relatively recent past (cosmologically speaking).

The source was linked in the article:
http://adsabs.harvard.edu/cgi-bin/bi...atur.371..313A

So yes, I'd say pretty reliable.

Matt Todd

Okay, so it's looking as though quasars aren't a one off, they seem to depend on availability of matter, dense and abundant matter being the trigger?

Drakkith

That looks correct to me.