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chornedsnorkack
2009-Aug-14, 03:51 PM
Active galactic nuclei seem to be hosted in disturbed, interacting galaxies. This makes sense: in an elliptical galaxy, there is no gas that could fall in a black hole, and in a stable spiral galaxy, gas and dust are on their respective orbits and cannot fall in a black hole, either.

The radio jets travel until they (usually) slow down and come to halt in intergalactic gas. Which takes a lot of distance. I think that there is a radio galaxy whose jets span 19 million lightyears.

Much more than the size of, say, Local Group. Are there any active galaxies whose jet happens to hit another galaxy? And what happens there?

antoniseb
2009-Aug-14, 04:13 PM
... Are there any active galaxies whose jet happens to hit another galaxy? And what happens there?

I'm unaware of any known system in which a jet hits another galaxy.
Just as an educated guess, I'd say that unless the other galaxy was a Satellite (like the LMC to the Milky Way), that the jet would hit the gas and dust in the other galaxy and pretty much stop.

It would be very bright in radio and XRays. I do not know what kind of radiation hazard the stream of Gammas and neutrinos would be to life bearing worlds in the other galaxy. I'm guessing that only a very close distance between galaxies would make it a threat.

Great question. Hopefully a more informed answer will turn up.

transreality
2009-Aug-16, 09:58 PM
If a civilisation were located in a radio galaxy would the use of radio for communications and astronomy be affected significantly?

matthewota
2009-Aug-17, 12:36 AM
I think that would depend on the orientation of the planet vis a vis the radio jet. If it was in line with the jet I doubt if life could even exist.

Bearded One
2009-Aug-17, 02:25 AM
Are there any active galaxies whose jet happens to hit another galaxy? And what happens there?I thought I saw a picture of exactly that not to long ago but I can't recall where I saw it if it wasn't on Phil's blog. If I find it again I will post a link.

RussT
2009-Aug-17, 09:06 AM
I thought I saw a picture of exactly that not to long ago but I can't recall where I saw it if it wasn't on Phil's blog. If I find it again I will post a link.

Yes, I saw that too, but also cannot find it. I have gone 4 pages back on the "Universe Today" story comments pages, and have not found it yet.

I would have to think though, that this is a very rare occurance.

chornedsnorkack
2009-Aug-17, 09:25 AM
Yes, I saw that too, but also cannot find it. I have gone 4 pages back on the "Universe Today" story comments pages, and have not found it yet.

I would have to think though, that this is a very rare occurance.

How much of our sky is spanned by galaxies of Local Group?

And Local Group is a sparse one. The big galaxy clusters are denser than this... there might be an appreciable chance that a radio jet encounters a nearby galaxy.

RussT
2009-Aug-17, 09:41 AM
How much of our sky is spanned by galaxies of Local Group?

And Local Group is a sparse one. The big galaxy clusters are denser than this... there might be an appreciable chance that a radio jet encounters a nearby galaxy.

I was going to add, and should have, that in all likelyhood, the galaxy that was being 'hit' by the Jet was a Dwarf Galaxy.

But, even then, Most dwarf galaxies are NOT flying right over (Or under;) assuming an edge on view, IF it were a spiral)) the SMBH Jets that are "Perpendicular to the Plane of the galaxy".

Also, 99.9% of those "Jets" are coming out of SMBH's in the center of Elliptical Galaxies, which have, over long eons, enveloped most if not all of their dwarf galaxies after N number of passes through the galaxy.

And, it appears, that almost all of the regular galaxies are orbiting the central cluster Elliptical Galaxy, and therefore NOT over the SMBH either.

ngc3314
2009-Aug-17, 11:03 AM
I'm unaware of any known system in which a jet hits another galaxy.

Minkowski's Object.

(At a meeting at the moment, will follow up if no one else posts links in the meantime).

trinitree88
2009-Aug-17, 05:18 PM
3C321 is pummeling it's neighbor. SEE:http://chandra.harvard.edu/resources/animations/quasars.html

RussT
2009-Aug-17, 10:45 PM
3C321 is pummeling it's neighbor. SEE:http://chandra.harvard.edu/resources/animations/quasars.html

Yep, that's the one........good find trinitree88 ;)



In 3C321, a jet from a black hole in one of the galaxies is pummeling its neighbor galaxy, the first time this type of galactic violence has ever been seen.