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Fraser
2005-Mar-21, 07:20 PM
SUMMARY: All Quasar's have black holes for hearts - but that doesn't mean they are unfriendly. In fact, 9 billion light year distant QSO2237+0305 may like us so much that it wants to make sure we see it even though it is actually hidden by a much nearer spiral galaxy. What can we learn from QSO2237+0305? For one, the cross that bears Einstein's name can tell us a lot about space-time curvature. For another, it can teach us invaluable lessons about how to see things otherwise hidden from view. If you have access to the scope and the skies, you too can see what the whole spectacle is all about.

View full article (http://www.universetoday.com/am/publish/planks_einstein_cross.html)

What do you think about this story? Post your comments below.

antoniseb
2005-Mar-21, 09:19 PM
Very nice article. I can just imagine the individual stars in the intervening galaxy sweeping across the face of the quasar, giving us randomly oriented scan lines in our cosmic video image of the accretion disk and jet.

It is interesting that the accretion disk is face on. This is in agreement with the model that quasars have their jets pointing straight at us.

Hyginus
2005-Mar-21, 10:45 PM
Dear Fraser et An(short for Antoniseb),
As one of Arp's self-appointed bravi and even though I'm not respectable as an astronomer, I believe I have a bit of an edge in the matter of the Einstein Cross controversy on the grounds that I have read his views for the second time now. Starting at page 173 ("Seeing Red") I understood him, but, by the time I waded to page 176, the water level rose so much that I developed theoretical gills to read on... In any event, The picture on page 176 sure looks favorable to his views!? So, don't spend my two cents on this matter any time soon in the hopes that they will be of any real value in our cosmic situation, Yr obt srvt, Hyginus

The Near-Sighted Astronomer
2005-Mar-21, 11:21 PM
It is interesting that the accretion disk is face on. This is in agreement with the model that quasars have their jets pointing straight at us.


Hi Antonseb,

Never considered this possibility before. I have viewed all kinds of galaxies through various instruments some present face on others at various angles. Some (Seyfert type Galaxies) have very luminous cores and present face on but are not bright enough to be thought of as quasars but it might be possible that the jets of such Seyfert galaxies if precisely oriented would be luminous enough for us to perceive them as quasars at huge distances.

Still uncertain though on the matter,

jeff

antoniseb
2005-Mar-22, 12:28 AM
Originally posted by Hyginus@Mar 21 2005, 10:45 PM
As one of Arp's self-appointed bravi
Do you mean this in the sixteenth century Italian sense of bravi = thugs? That doesn't seem like a good match for you.

None-the-less, since I don't plan on reading "Seeing Red", could you please summarize why Einstein's cross is favorable to Arp's views?

madman
2005-Mar-22, 01:54 AM
the lensing galaxy PGC 69457 is 400mly away....that's the same distance as the tadpole galaxy that was imaged in great detail by the newly installed acs (on hst 2003).

it would be nice to see an image of the einstein cross with that resolution.

Truthseeker
2005-Mar-22, 02:45 AM
Gravitational Lens or Redshift Anomaly?
In the mid-1980's, astronomers discovered these four quasars, with redshifts about z = 1.7, buried deep in the heart of a galaxy with a low redshift of z = .04. (The central spot in this image is not the whole galaxy, but only the brightest part of the galaxy's nucleus.) This could have been seen as a crucial verification of Halton Arp's discordant redshift associations. It could have been proof that the redshift-equals-distance relationship is fatally flawed. Instead, Einstein's space-warping principle was invoked, and astronomers announced they had discovered a single distant quasar split into four images by the gravity of the foreground galaxy. A galaxy-sized fun-house mirror!
But how well does the image fit the theory? Einstein predicted that light from a distant object that was gravitationally warped around a massive foreground object would form arcs or even a full circle. Here we see four bright spots and no ring-like elongations. In fact, all four of the bright spots are elongated in the wrong direction: they stretch toward the galaxy center.
More observations were undertaken. Using the Hubble Space Telescope, a friend of Arp's documented that quasar D is physically connected to the nucleus of the galaxy. Later, a high redshift connection was discovered between quasars A and B which passes in front of the connection between the nucleus and quasar D. But these observations went unnoticed: the journal which usually prints results from the Hubble Space Telescope rejected this announcement twice.
Mathematical analysis, too, casts doubt on the gravitational lens theory. The faint foreground galaxy would need to be much bigger and brighter in order to accomplish this lensing feat: In fact, it would have to be 2 magnitudes brighter than "conventional quasars," the brightest objects known.
There are more answers than are conventionally distributed.

The Near-Sighted Astronomer
2005-Mar-22, 03:29 AM
Hi Folks,

Personally I was quite surprised on researching this article that the lensing elements within the galaxy were of such a low mass. In fact I carried a presumption into the research that the galaxy's own black hole was the lensing element. Then as i got in deeper i though that like our own galaxy there were a group of smaller black holes outside the main one doing the lensing. Later (with a prompt from antonSEB i noticed that their were five bown dwarf stars supposed to be responsible for the lensing - not even black holes!

But as to other points each brown dwarf supposedly captures the view of the quasar from a discrete perspective - my own suspicion is that only part of the accretion disk is seen from each and that is the basis for the lensing and the fact that the four views can act to reveal data on different parts of the quasar.

jeff

antoniseb
2005-Mar-22, 04:00 PM
Originally posted by The Near-Sighted Astronomer@Mar 22 2005, 03:29 AM
Personally I was quite surprised on researching this article that the lensing elements within the galaxy were of such a low mass. In fact I carried a presumption into the research that the galaxy's own black hole was the lensing element.
The mass of the galaxy (mostly its dark matter) caused the lensing of the quasar into four separate images. When observing the images we find that they do not brighten and dim simultaneously, but have different lengths for their light paths. We have correlated this rise and fall and found that the images match exactly once this is accounted for... exactly except that once in a while there is a microlensing event in one of the four images, increasing its brightness, and changing its spectrum. The microlensing events happen as an object in the galaxy moves (from our perspective) across the face of the quasar's black hole and accretion disk, amplifying the light from a small portion of that image on it's path across the face, so what we see, if we watch it continuously, is a single line in the image of the accretion disk and jet of the quasar.

THAT is why this story is so cool. If we look very carefully at Einstein's Cross for the next ten or twenty years, we'll be able to see a very clear image of the changing nature of the accretion disk and jets, detailed perhaps to a resolution of a small fraction of an AU, with good spectral information. This is incredible for something that is nine billion light years away.

Hyginus
2005-Mar-22, 04:51 PM
Dear Antoniseb,
Re: your post of Mar 22, 05, 12:28 am. What can I say, except touchee?
I guess my problem is I'm presently re-reading Dumas' 2nd sequel to "The Three Musketeers" (popularly known as "The Man in the Iron Mask") which contains some of the best dialogue in literary history, IMHO. As examples of "good" bravi, you may recall the Fab Four acted as bravi for Anne of Austria in the Affair of the Diamond Studs and as bravi in their attempt to save Charles I from the scaffold in Part Deux. In any event, to keep the metaphor going, I was about to dip my quill into inkpot in response to your post when I came upon Truthseeker's post of Mar 22, 05, 02:45 am which is a brighter and crisper precis than anything I would have writ on behalf of Arp's stance vis a vis Einstein's Cross. Then came the response of The Near-Sighted Astronomer(above) who asserts five(?) brown dwarves, not black holes, are lensing a background QSO. News to me! Is the plot thickening?
Yr obt srvt, Hyginus

The Near-Sighted Astronomer
2005-Mar-22, 07:26 PM
The mass of the galaxy (mostly its dark matter) caused the lensing of the quasar into four separate images. When observing the images we find that they do not brighten and dim simultaneously, but have different lengths for their light paths.


This is more in accord with my own concept of how gravitational lensing occurs. The foreground galaxy's total mass refracts all light from the distant quasar. What is of particular interest to me is the fact that normally such lensing would create a single refracted image of the quasar in exactly the way an orb of glass images distant objects. Now of course the grvitational field of a galaxy is NOT a single transparent lensing element - it possesses many occlusions (some of which have their own lensing fields) and this could conceivably act more like a crystal with facets. Such facets could then cause a multiplicity of views of the quasar. And each of these facets should be capable of highlighting a specific "perspective" on the quasar amplifying variations in energy output from some small region near the black holes UV source.

So OK i now understand AntonSEB's input - yes? But what is this Arp perspective I'm hearing "championed" by others? The sense i get is that this perspective is a "reposte" against the redshift notion giving rise to the concept of universal expansion...

jeff

antoniseb
2005-Mar-22, 08:49 PM
Originally posted by The Near-Sighted Astronomer@Mar 22 2005, 07:26 PM
what is this Arp perspective I'm hearing "championed" by others?
There is a thread in Alternative Theories about Arp's ideas. Further discussion about that aspect of this should go there. Briefly stated, they see Einstein's Cross as four separate different quasars that have been ejected from the lensing galaxy. The fact that they all have identical redshifts is an indication to them that they were ejected during one event, and have some mysterious property that causes an intrinsic (non-cosmological) redshift.

antoniseb
2005-Mar-22, 08:52 PM
Originally posted by Hyginus@Mar 22 2005, 04:51 PM
I'm presently re-reading Dumas' 2nd sequel to "The Three Musketeers" (popularly known as "The Man in the Iron Mask")
Oops, sorry, I read it in French thirty-five years ago, but didn't retain the word bravi.


five brown dwarves, not black holes, are lensing a background QSO. News to me! Is the plot thickening?

I don't think this complicates things. this is as I described in my post of Mar 22 2005, 04:00 PM. It is a very easy to understand idea using only well known physics.

The Near-Sighted Astronomer
2005-Mar-22, 09:17 PM
Thanks AntonSEB for the Arp perspective.

As i understand it these four refracted images are very stable and more or less identical in terms of their output - most of the time - and it is only during an HAE that they display any differences in output. To my way of thinking this discounts the Arp hypothesis of four separate entities since each one should show a good deal more intrinsic variability in their output...

antoniseb
2005-Mar-22, 10:25 PM
Originally posted by The Near-Sighted Astronomer@Mar 22 2005, 09:17 PM
To my way of thinking this discounts the Arp hypothesis
It's best to continue this in the More on Arp Thread in Alternative Theories. Some of our members care passionately about this subject, and have written much on this topic there.

Dave Mitsky
2005-Mar-23, 03:54 PM
I once saw PGC 69457 and one of the four lensed arcs through a 24" Tectron Dob at Cherry Springs State Park, a site that has a visual limiting magnitude of about 7.0 on the best of nights. It was one of the most difficult observations that I've ever made.

http://www.skyhound.com/sh/archive/sep/Q22...2237+0305A.html (http://www.skyhound.com/sh/archive/sep/Q2237+0305A.html)

Dave Mitsky

Hyginus
2005-Mar-24, 05:00 PM
Dear Antoniseb,
I crave leave to paraphrase your post @Mar 22,05,04:00pm: the four images of one QSO vary in brightness but not simultaneously in apparent contradiction to one lens doing the imaging. I wonder why other QSO's (certainly not being lensed) vary in brightness, and how one could say this is intrinsic change and these four images is a lensing artifact? Yr obt srvt, Hyginus

The Near-Sighted Astronomer
2005-Mar-24, 07:14 PM
Hi Hyginus,

I believe that all QSO's are variable since their power source (assimilation of orbital material) is not constant. If a single lensing object were to bring light to our eyes we would see a pattern of luminosity variations that - if not being absolutely simultaneous - would be predictable in their sequence and with only slight delays (due to slight but potentially variant gravitational pathing factors).

The four lensing bodies however capture light from different perspectives of the UV source surrounding the SMBH. This makes any "pattern recognition" based on different light-paths of the same behaviors impossible. And it is the uniqueness of these HAE's and their staging that allowed the analysis team to see "details" concerning the accretion disk as well as assay the masses of the microlenses involved.

Hope this clarifies things,

jeff

The Near-Sighted Astronomer
2005-Mar-24, 07:16 PM
Hi Dave,

I did some research on the least aperture required to see the cross. One website specified 18 inches of aperture - sounds like it might actually require a bit more than that based on your observation.

jeff

PS: By calculation a 500mm /20 inch scope should just hold the four 17th magnitude quasar images through 7/10 seeing stability and 7.0ULM skies at 180x.
Under more likely 6.0 skies one might hold them on fully averted sight...

Hyginus
2005-Mar-28, 02:54 PM
Dear Near-Sighted Astronomer,
Re:Mar 27 05 APOD of Einstein's Cross.
The galaxy supposedly lensing 4 QSO's looks like a Seyfert galaxy to my untutored eyes. Arp's scenario involves such galaxies and QSO's. The debate goes on with or without further comments from yr obt srvt, Hyginus

antoniseb
2005-Mar-28, 03:28 PM
Originally posted by Hyginus@Mar 28 2005, 02:54 PM
The galaxy supposedly lensing 4 QSO's looks like a Seyfert galaxy to my untutored eyes.
It looks sort of like a Seyfert, except that there is no bright core, except for the four quasar images, whose redshifts do NOT match the rest of the galaxy. I suspect you knew these facts, and assume the above post was only trying to make (harmless) trouble, but if so, how do we know when you're being serious?

Hyginus
2005-Mar-28, 11:55 PM
Dear Antoniseb.
Re: your post @ Mar 28,05, 03:28pm
On page 177 of Arp's "Seeing Red" There's a photo of Einstein's Cross with a semi-detached 5th blob of light I take to be the nucleus of the galaxy. I assume bright nuclei of Seyfert's give birth to QSO's until whatever mechanism is working runs out of steam. As for humor in my posts, it's merely an attempt at a thin layer of sanity to hide my lack of omniscience about the appalling universe and whatever else lies beyond yr obt srvt, Hyginus

Dr.Dong-Wook Lee
2005-Apr-05, 03:25 AM
Truthseeker said, "But how well does the image fit the theory? Einstein predicted that light from a distant object that was gravitationally warped around a massive foreground object would form arcs or even a full circle. Here we see four bright spots and no ring-like elongations. In fact, all four of the bright spots are elongated in the wrong direction: they stretch toward the galaxy center."
*** However, this is not true at all.****
My answers are;
1) The reason why there is no ring like image in the Einstein Cross is that the lensing galaxy has also external perturbations. In such a case, the corresponding caustic is diamond shape, not a single ponit. If the source is smaller compared with the diamond caustic and located inside the caustic, then the lensed images are normally 4-components. Also, most of lensing galaxy observed so far produce the typical diamond shape caustics and 4 or 2 lensed images!!!
Only if the source size is compatible with the diamond caustic, the ring image can occur.
This fact is mathematically evident!!!(All GL astronomers know this fact!).

When a single lens without external perturbations (in this case the casutic is a single point)acts as a lensing object, if the source is exactly behind the lens, then the ring image will appear.
So this explains why the Einstein Cross have 4 lensed iamegs instead of a ring image!!!

2) If you look into high resolution HST images for the Einstein Cross, you can nerver say again the images are elongated toward the center of galaxy!!!

Please visit this WWW site;
http://cfa-www.harvard.edu/castles/Individ...dual/Q2237.html (http://cfa-www.harvard.edu/castles/Individual/Q2237.html)

Best regards,
D.W.Lee

Hyginus
2005-Apr-10, 09:05 PM
Dear Fraser,
Re: Your post of Mar 21, '05, 07:20 PM
The summary begins by asserting, "All quasars have black holes for hearts..." When it comes to the movement(s) skeptical of BH's and counter-proposing that quasars begin ejected as "point-sized" Machian vacuities, you'll find me back at the baggage train asking questions, e.g. since when are quasars only three magnitudes fainter than an interreacting "spiral" looking like an elliptical dwarf? In any event, while deeper and better questions are pupating, I remain yr obt srvt, Hyginus