Quasar intacting with Galaxy?
http://ucsdnews.ucsd.edu/newsrel/science/mcquasar.asp
snowflake
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Quasar intacting with Galaxy?
http://ucsdnews.ucsd.edu/newsrel/science/mcquasar.asp
snowflake
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Perhaps the best example for an intrinsic red shift. Even better would be confirmation of one with a definitive proper motion.
Order of Kilopi
This report does not apparently remove the question mark from this question. Notably....Originally Posted by snowflakeuniverse
Note the "if".
"Closely associated" does not necessarily mean "within" or "interacting with".
Appears? So they're not sure if the quasar is actually interacting with the galaxy or if it just appears to be.
What a surprise.
This particular quasar has been discussed in depth on this board some time ago. I don't see anything new in this article or the summarized "new finding" which is to be published in an upcoming issue of Astrophys. J.
Everyone is entitled to his own opinion, but not his own facts.
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This is just my opinion, but words like "if" and "appears" should always be used when discussing scientific matters, because there are not many sure things in science. So I think that this kind of approach should also be used when reporting about findings that support the Big Bang theory.
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From the article it seems that the quasar does not have unshifted spectral lines from the galactic interstellar gas. I conclude from that that the quasar is a foreground object if it is not associated with the galaxy.
Order of Kilopi
Well, certainly not always. When describing findings, observations that are verified and repeated do not need such caveats. The redshift of the quasar in question here was found to be much greater than the galaxy's. The redshift doesn't appear to be greater; it is greater. Unless someone can explain how spectral lines can be greatly shifted without being at a great distance, I must conclude that the quasar is a deep background object, and its "association" with the foreground galaxy is simply coincidental.
Everyone is entitled to his own opinion, but not his own facts.
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Ok, I can tone it down to "almost always".
Unless there is some systematic effect making all observations of the phenomenon in question invalid...
...like in this case. What if that quasar is actually some low redshift object (foreground star for example) and for some reason our redshift measurements give too high value? In that case redshift only appears to be greater, in reality redshift would be lower.
In that case you need something like a properly placed and sized hole in the galaxy in order to see the quasar.
Hmm, I wonder if this could be explained by gravitational redshifting. If that quasar would be a black hole with fantastically high mass, would it be possible that it would cause enough gravitational redshifting?
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If it's a deep background object, it should have the low shifted lines as well as the high shifted lines. As I read the article, the low shifted lines aren't there.
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If you look at today's APOD and view the blow up version of the galaxy, it appears that there are several smaller and yellow-orange objects that seem to be red-shifted background galaxies. A couple of these are well inside the galaxy near the center. If these are indeed galaxies, then maybe it is possible for a background galaxy or quasar to shine through the big galaxy.
http://antwrp.gsfc.nasa.gov/apod/ap050112.html
edit: In fact this is what the poster says on the link to the APOD.
http://heritage.stsci.edu/2005/01/supplemental.html
Order of Kilopi
Yes, plus the images supplied in Snowflake's initial post may be somewhat misleading. With computer software it's very easy to increase a photo's contrast and saturation, making for a more stunning photo, but adding the appearance of dense luminosity where only a thin wisp of gas was to begin with. Perhaps it's a true riddle why the subject quasar's spectrum does not readily show absorption lines from the foreground galaxy.... or perhaps not.
Everyone is entitled to his own opinion, but not his own facts.
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They've got a decent case that this isn't a background object.
They see no indication of interference from the galaxies interstellar medium. This sort of interference should be there if the quasar was behind the galaxy, shining through it.
The proximity of the quasar to the galactic core is mere circumstantial evidence, but does contribute to the idea of an interacting quasar.
BTW, another source of redshift (even really high and relativistic redshifts) is high velocity...which is mimiced by the cosmological redshifting.
These odd interacting quasars may merely be ejected Active Galactic Nuclei. The core supermassive BH's may end up getting pretty close in a multibody system (say 3 SM BH's) and one gets thrown out, with its entourage of galactic debri still fuelling it.
That's my guess without completely rewriting the science of quasars and cosmological redshifting.
I'll see if I can't ask my supervisor (a quasar researcher) on his take, he may even have heard the talk personally.
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Those that are nearest the center of the galaxy, doesn't appear to be reddened (there is only white objects very close to the center) like the ones that are further from the center (couple of good examples are seen in the spiral arm at the bottom of the image), so I don't think the objects seen very close to the center are background galaxies. This same thing applies also to NGC 7319, there are reddened objects further away from the center, but near the center, where the quasar also lies, there are none.
So, I still think that if the quasar would be a background object, we wouldn't see it.
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And the redshift would be due to velocity? In the NGC 7319's case, the quasar would be flying away from us with velocity of about 2c. In that case it doesn't seem to be ejected from NGC 7319 because we see the quasar in front of NGC 7319. So, where would it be ejected from in this case? And what would cause the faster than light velocity?
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Actually the velocity is always less than c unless you don't believe special relativity. It certainly approaches c however for a shift of 2.11.
There was considerable analysis done in the 60s on whether a quasar red shift could be due a local ejection from our own galaxy. The lack of blue shifts, the lack of correlation with the galactic plane, the lack of proper motion all were objections to this; but the issue is still not entirely closed.
The work was done by a guy from Los Alamos. I can't remember names anymore. I have his paper in my basement in Colorado, but now I'm working in St. Louis.
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Unfortunately, I have to disagree with you. If you click on the picture and then on the expansion icon in the lower right corner you get a big version of the image. Look in the image near the 3 o'clock position near the center of the galaxy and you will see what appears to be a background galaxy shining through the galaxy near the center. There is another possibility of one even closer at the 9 o'clock position. However, quasars are usually pretty dim so they may not shine through like a galaxy would.Those that are nearest the center of the galaxy, doesn't appear to be reddened (there is only white objects very close to the center) like the ones that are further from the center (couple of good examples are seen in the spiral arm at the bottom of the image), so I don't think the objects seen very close to the center are background galaxies. This same thing applies also to NGC 7319, there are reddened objects further away from the center, but near the center, where the quasar also lies, there are none.
So, I still think that if the quasar would be a background object, we wouldn't see it.
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Really? That's good to know, thanks!
So I quess I have to modify my last question to Ricimer to And what would cause the near c velocity?
That 3 o'clock object was one of the objects I meant when I said they are not reddened. At least in my monitor that object looks white, not orange. Further out there are more galaxies roughly in 3 o'clock direction which are yellow/orange, but I assume you mean that white fuzzy object that is closest to the nucleus of the galaxy in that direction.
As far as I know, galaxies seen through other galaxies should be reddened. This is not, so I assume it is not background object. Perhaps it is foreground dwarf companion, or tight cluster of stars within the galaxy. Redshift value for that object would be interesting to know.
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Given the large amount of evidence we have that quasars are located at great distances, it seems more parsimonious IMO to assume that its a line-of-sight coincidence, and that there's just something about the ISM of this galaxy that we don't know about.
If it somehow is associated with the galaxy, then we have to explain how such a relatively nearby object got such a enormous velocity, far and away higher than that found for any galactic object aside from neutron star or black hole polar jets. We would also have absolutely no idea what this object is, because if it's located in the galaxy it would have to be extremely luminous to be that prominent in the imagel; I doubt even a trinary system of OB supergiants would be that bright. Most likely we'd have to invent a whole new category of object to even begin to understand it. Maybe more detailed spectra will answer this question.
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what would cause the near C velocity:
Well, in my possible explaination: We're dealing with a multi-body system, where objects can be ejected at high speeds. We're also dealing with black holes, the most intense gravitational sources possible.
So...it's possible (even if it isn't likely it's still possible) for such an interaction to produce high velocity ejections. How high, i'm not sure. An ejection with speed sufficient for a 2.11 doppler shift...may be so highly improbable that it isn't likely (considering the fact that we see a decent number of these odd interacting quasars).
The biggest problem, is one you pointed out and one I just plain overlooked: If the quasar is a forground object, and it was ejected by the galaxy "behind" it...then the shift should be a blueshift, not red.
So if the quasar is a foreground object, My idea just plain died an ignoble death.
Order of Kilopi
I kind of like this explanation and have proposed it in other threads, BUT as dgruss has pointed out, the anecdotal evidence (well, he didn't call it that!) shows a number of examples of apparent quasar-galaxy associations, and most of the quasars have redshifts that are MUCH larger than the associated galaxy. But if these were simply orbital slingshots, so to speak, they should be flung every which way, not just away from us, as it appears most examples are. SO... I will retreat to ponder the meaning of the word parsimonious.... :P
Everyone is entitled to his own opinion, but not his own facts.
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Well, I am in the camp that says that quasars have an intrinsic non-doppler red shift. I think it's Compton, especially if the quasar is a strong radio source.
I have not seen a radio map for the Burbidge quasar.
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I just don't get it. Why is it the first time you hear a word, it pops up somewhere else too?!
The first time I heard parsimonous was when I took the general GRE's. It popped up 5 times during the verbal section, and each time I had no clue what it meant!
And now you say it.
Go figure.
BTW, it means exceedingly stingy or frugal.
It's a work I won't soon forget.
John, I take it you mean compton scattering right?
If so, where the heck are you getting all that material! Shining light through a very, very concentrated beam of electrons in a lab would produce an observed compton scattering event once every hundred years or so.
The only way to approach the electron density needed for compton scattering is to use a solid object, and extremely high energy photons.
This would also produce a frequency dependent redshift as different photons are more or less likely to hit electrons than others.
Order of Kilopi
This arguement reminds me of the TMR-1C images taken a few years ago. Supposedly a planet ejected from a young star system was clearly visible at the end of a trail of gas. The image lined up so perfectly, I even recall a 3D model of what the system was believed to have looked like.
Turns out, it was a background star all along.
Without further observation, trying to use this one released image as a pillar on which to try and stand intrinsic red shift is a risky proposition.
Order of Kilopi
It could still experience doppler blueshifting, but the overall spectral shifting would be redshifted because the intrinsic redshift would be much larger than the doppler blueshifting ... if the Arp et al interpretation be correct. The measured redshifts can have multiple factors contributing. In the ejection scenario, the intrinsic redshift mechanism would have to dominate or we would see actual blueshifted quasars.
Order of Kilopi
The observed redshift is almost certainly not a doppler redshift if it is local. There must be some intrinsic redshift mechanism. Perhaps that means new physics, perhaps that means different applications of known physics to scenarios the physics has not previously been applied to.
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Here's one paper that gives radio maps of NGC 7319.
They mention that paper in the paper discussing this quasar (in conclusions chapter, page 9).
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Each day, the people who use femtosecond lasers observe thermodynamically allowed transfers of energy between beams refracted by a common medium. These transfers produce frequency shifts and are very strong if the coherence is preserved, that is if the geometry of the beams is preserved. The laws of these effects have been computed and verified experimentally.
It is generally assumed that beams of light propagating in a common refracting medium do not interact. These laser experiments show the contrary. Replacing, in the theory the parameters of the laser light by the parameters of ordinary incoherent light (much more time-coherent) shows that the strong transfers of energy occur only in particular gases, in the practice in atomic hydrogen, in states 2P or 2S. It is the CREIL.
Very easy to use: only search this excited atomic hydrogen, mostly generated by a Lyman alpha pumping by a very hot source (quasar), or by the combination of protons and electrons (producing the increase of frequency of the radio signals of the Pioneer probes by transfer of energy from the solar light where the cooling of the solar wind produces neutral, excited H atoms).
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The problem I have with invoking an intrinsic redshift is: We know of no suitable mechanism for it. The redshifts observed are not anomalous redshifts, they appear to be the same sort of redshift as any other velocity induced redshift.
JMB: How does interacting with hydrogen at two specific quantum states uniformly shift the entire energy spectrum?
I understand how it can absorb light, then re-emit it in a different region of the spectra. This does not however produce a redshift. It merely creates absorption and emission lines.
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Maybe quasars are ejected from galaxy cores with extremely high rotation rates, such that there is a very high relativistic Doppler shift (proportional to v^2/c^2). If you take Arp's idea that the quasar is a nascent galaxy, which will eventually come to rotate at a few hundred km/sec, then its initial rotation rate would have to be very much higher given its small initial size relative to a typical spiral. In this case, quasar light would have components that are either extremely blueshifted or redshifted, due to ordinary first-order Doppler effects arising from quasar matter moving rapidly towards us or away from us. The redshift we actually record would be due to matter moving laterally relative to us. This could explain redshift quantization too, since the angular momentum of the quasars could be quantized, just as planetary orbits seem to be.
Hey, this is even testable!
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Why don't we then see the blueshifted components?
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They would be shifted so far away from the middle portions of the spectrum (the latter arising from transversely moving quasar matter) that you would have to make a special search for them. It would be akin to the original discovery that quasar light was ordinary starlight redshifted to a huge degree. I wonder if they have looked at the far ends of the quasar spectra.
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