While reading a lengthy article about active galaxies and quasars (here, for those interested), I had a thought I want to put here, for people more familiar with these topics than I am. It may provide further evidence that Arp and his followers are wrong, and provide strong evidence for an expanding Universe and the Big Bang.

When a spectrum is taken of a high-redshift quasar, it invariably shows a series of absorption lines blueward of the Lyman alpha line (this is the emission line of hydrogen where the electron drops from the 2nd to the 1st energy level, and has a wavelength of 1216 Angstroms).

The standard explanation is that there is gas between us and the quasar. This gas, being closer to the quasar, sees the quasar at a lower redshift. We might see the Lyman alpha line redshifted to, say, 2432 Angstroms (at a redshift of 1), but the gas sees it as a redshift of 0.5. The gas absorbs this light, leaving an absorption line in its spectrum at where it sees the quasar's Lyman alpha.

However, the gas is redshifted with respect to us too, but not as much as the quasar, so we see this absorption feature to the blue of the Lyman alpha line from the quasar.

If there are lots and lots of gas clouds between us and the quasar, we would see lots and lots of absorption lines; a "forest" of them, all blueward of the emission line from the quasar itself. This is what's called the Lyman alpha forest, and to the best of my knowledge appears in every single high-redshift quasar spectrum.

I see this as a major problem with Arp's interpretation of redshift being something internal to the quasar. In his book, "Seeing Red", he claims that quasars are ejected from galaxies, and their redshift changes as they age. It has little or nothing to do with distance. The redshift is happening due to "new physics" inside the quasar itself.

So how does he (or his followers) explain the Lyman alpha forest? The forest falls naturally out of a redshift/distance correlation, but not if the redshift is intrinsic. The gas all has to see the quasar at different redshifts, but this is not possible if the quasar itself is the source of its own redshift.

Is this the nail in the coffin of Arp's theory? I have not seen it discussed in this way elsewhere.

I agree, Phil, that such evidence seems damning. I've mentioned it before and received the comment that the intrinsic redshift might be related in some sort of potential to the outside. In other words, that the absorption features might not be intergalactic clouds at all but rather intrinsic to the quasar itself.

I find this preposterous because we see the same z-absorbers in quasars that are on similar lines of sight but with different redshifts. Why should the features in one intrinsic quasar be the same in another one only when they are on the same line of sight? I mean, the quasars are different (at different redshifts) and yet they show the same absorption features with the SAME OPTICAL DEPTHS! This is a ridiculous coincidence that the intrinsic redshifters have NEVER explained to me, even though I've mentioned it numerous times.

Hey I like that easy to understand (for a non-astronomer) explanation of why Arp is wrong. Though I never thought that his connections between near-by galaxies and quasars looked all that impressive. If anything I am surprised that he was not able to find more of them by chance alignments.

I do have a question. I can think of a way that could really put another nail in coffin of Arp's hypothesis. Take one of the galaxy/quasar pairs that Arp says are physically connected. If the quasar is really much further distant than that Galaxy and the appearent connection is just the result of a chance alignment between the quasar and the galaxy, then should it not be possible that quasar's light will be absorbed by gas from that galaxy? If the answer is yes, the observational consequence would be very obvious.

The king of Bad Astronomers has made a point that is already enshrined in the inscrutable aether of the scientific literature.

Evidence consistent with the cosmological interpretation of quasar redshifts
En-Wei Liang & Yi-Ping Qin
Publications of the Yunnan Observatory 90(2): 16-21 (2002)
Abstract: We select a sample including 401 sources in which both absorption and emission redshifts are available from the table 1 in Hewitt and Burbidge (1993). The sample is the largest one for the investigation of the quasar redshifts so far. It is found that most of the absorption redshifts (93.6%) are smaller than the corresponding emission redshifts, and the result is consistent with the conclusion drawn from a small sample in 1970s. The result indicates that the redshifts of quasars are indeed distance indicators. That is consistent with the cosmological interpretation of quasar redshifts.

The problem is the relative obscurity of the source. Not everybody has the Publications of the Yunnan Observatory laying around, and many of the abstract archives don't include it either. It's just my luck that I found the paper at the Caltech library (which does have the Publications of the Yunnan Observatory laying around in the astronomy department library). I saw the paper, but don't think I have a copy. They have a nice plot of all the quasar redshifts vs Lyman-alpha redshifts. It's a pretty impressive picture.

Along with the Lyman-alpha forest, one might include the logically connected Gunn-Peterson trough, caused by the absorption of neutral hydrogen in the universe, before the epoch of re-ionization (or so standard cosmology predicts). Long a theoretical expectation, the Gunn-Peterson trough is now an observed reality (VLT optical and near-infrared observations of the z=6.28 quasar SDSS J1030+0524, L. Pentericci et al., Astronomical Journal 123(5): 2151-2158, May 2002; A survey of z greater than 5.8 quasars in the Sloan Digital Sky Survey. I. Discovery of three new quasars and the spatial density of luminous quasars at z similar to 6, X.H. Fan et al., Astronomical Journal 122(6): 2833-2849, December 2001; Evidence for reionization at z similar to 6: Detection of a Gunn-Peterson trough in a z=6.28 quasar, R.H. Becker et al., Astronomical Journal 122(6): 2850-2857, December 2001).

I like to think that the combo of Lyman-Alpha forest & Gunn-Peterson trough are like a one-two punch that needs to be dealt with by anyone who thinks redshifts of quasars are non-cosmological.

harlequin ... If the quasar is really much further distant than that Galaxy and the appearent connection is just the result of a chance alignment between the quasar and the galaxy, then should it not be possible that quasar's light will be absorbed by gas from that galaxy? If the answer is yes, the observational consequence would be very obvious.

There are published papers which show just that. The galaxy absorbs quasar light, showing that the quasar lies in the background. Not all of the suspicious galaxy-quasar pairs show this, but at least some can be discounted for the reason you cite (examples, New observations of the gas cloud associated with the quasar-galaxy pair 3C-232 NGC-3067, J.T. Stocke et al., Astrophysical Journal 374(1): 72-82, Part 1, June 10 1991; Properties of low redshift QSO absorption systems - QSO-galaxy pairs, D.S. Womble, Publications of the Astronomical Society of the Pacific 105(691): 1043-1050, September 1993). I have posted other examples in other threads, but unfortunately I am not so well organized as to have them handy.

I hope I didn't misspell shift again.

Cheers.

Tim, you're the Man. [img]/phpBB/images/smiles/icon_smile.gif[/img]

I'll note that there is a description of the Gunn-Peterson effect in the paper I linked in my original post to this thread.

It's nice to know I can be backed up with science.

Please don't y'all consider me as a believer in close quasars or Arp/Narlikar's "new physics" (which I hate yet deeper than the Big Bang itself), but why don't you consider a hydrogen atmosphere around the quasar itself? The thing might be very heavy to produce local redshifts, yet charged too much to collapse. Anybody ever modelled that?

I would think that an atmosphere at best would cause a broadening of the line, because the redshift would be continuous, rather than the discrete lines that make up the Lyman alpha forest.

<font size=-1>[ This Message was edited by: Zathras on 2003-01-16 11:24 ]</font>

That must depend on the density. After all, that light gets that much hydrogen anyway...

But my question was were there any attempts of the nature I mentioned, or any serious consideration for "intrinsicness" at all (I mean - no overly new physics).

This is a perfect example of desperate hand waving that quacks will go though to get around the evidence. How could an "atmosphere" of a quasar have a redshift that is both different and distinct from the quasar itself?

[Edited to improve clarity and grammar.]


<font size=-1>[ This Message was edited by: harlequin on 2003-01-16 14:57 ]</font>

Agora, but two different quasars on similar lines of sight show convergeant signals from z-absorbers at EXACTLY where we see, for example, the Virgo cluster. How could those signals be part of the quasar atmosphere?

Come on, you can't possibly be that intellectually crippled yet still able to write a post...

Tim,

Thanks for confirming my hunch.

Bad Astronomer (or Tim),

This would a great subject for a page. This is something that be easily explained to people without a technical astronomy background.


===================

There is another posible way to use this sort of argument. Maybe Tim or J S Princton (whose post influenced this) can say if it has been done. Say there are two quasars that whose position to each other two-dimentionally (i.e. not counting distance) is fairly small. There are far enough from the line of sight for Arp not to claim they are "connected" but close enough to the line of sight to have there light absorbed by the same "cloud" of hydrogen. They will get some lines in their spectrum from it. Princeton said this has been done in his reply to The Bad Astronomer. But the farther one can also get absorption from
hydrogen that is even further out that the
other quasar does not have. Has that been observed?

If someone can show some examples of this, then I say that we can say with about as close to absolute confidence as one get in the real world that non-mainsteam explanations of the red shifts are false.

That would be a coincidence for Arp to match! [img]/phpBB/images/smiles/icon_smile.gif[/img] Yet I'd ask a few questions -
Are there parts in their absorption spectra that don't match, yet come from atomic hydrogen; what's the weight of convergent parts?
Do the "closest" quasars exhibit appropriately less forest effect?

<font size=-1>[ This Message was edited by: AgoraBasta on 2003-01-16 14:54 ]</font>

No ducks here.

Latest discovery from Hubble.
For years, double cosmic clouds of radio emission such as those flanking this spiral galaxy's core have been studied and cataloged. But, at least until now, such radio sources were only known to arise from the cores of giant elliptical galaxies or in violent merging galaxy systems, making 0313-192 the wrong kind of galaxy to be found in this scenario. Astronomers are searching for clues to why this spiral galaxy, potentially similar to our own Milky Way, shows such powerful activity.

http://antwrp.gsfc.nasa.gov/apod/ap030114.html

The only parts that don't match are the parts from redshifts that are larger in one than the redshift of the other object.

There definitely are fewer absorption features in quasars that have lower redshifts.

Thus hydrogen atmospheres won't help them... I have no doubt they'll find some fun elsewhere. [img]/phpBB/images/smiles/icon_wink.gif[/img]

In addition to the ones that Tim mentioned, there's also the case of the most famous of the so-called alignment systems involving the quasar Mrk 205. The quasar's spectrum shows narrow MgII absorption lines at the redshift of the foreground galaxy (with the so-called 'bridge').
http://adsabs.harvard.edu/cgi-bin/np...e2780004c02697

But besides these Arpian cases, there must be many dozens (hundreds?) of known cases of quasar absorption line systems observed along lines of sights that lie near or through the disks and halos of spiral galaxies (Lyman limit and damped Lyman alpha systems). (Papers by Ken Lanzetta, Chuck Steidel, many others)

As for the gas that lies between galaxy clusters responsible for the vast majority of the low column density absorption lines, simulations of the formation of large scale structure in an expanding universe can actually reproduce the Lyman alpha forest and its evolution with redshift (it thins out at low redshift -- just a dozen or so lines in the spectrum of 3C 273 and other "nearby" quasars, and the forest becomes totally opaque for wavelengths shortward of the Lyman alpha emission line by the highest redshift quasars z > 6). (numerical modeling papers by Neil Katz and David Weinberg, others)



<font size=-1>[ This Message was edited by: Spaceman Spiff on 2003-01-16 23:09 ]</font>

I dont arguing against what you said,but the fact than the Lyman alpha forest appears ONLY in every single high-redshift quasar spectrum and is not visible in lower Redshift quasars imply a limited aera (zone)of gas clouds centered around high redshift quasars or the Layman alpha forest should be visible on all redshift of Quasars not only the high redshift.Because we would see the absorption lines each time the light of the Quasar -even with a lower redshift- travel through a gas cloud betwen us. This should be visible in the spectrum line for all quasars observed?

<font size=-1>[ This Message was edited by: Orion38 on 2003-01-17 17:40 ]</font>

Orion, there are two effects: one: there are fewer clouds of absorbable material to go through for lower redshift quasars. Two, the way redshift works, especially high redshift, you end up with "length contraction" effects. That's why it's a forest, because even though you've gone way, way out, you have a finite amount of wavelength space in which to absorb all the way back to z=0. This means that most of your absorbers tend to cluster up in the higher-redshifts (thus looking like a forest).

Low redshift, the formula reduces to v=zc and so you needn't worry about running out of wavelengths to absorb back down to rest-frame Ly-alpha.

Arp has his own forums. Have any of you posted there your doubts & received responses from him or his devotees?

http://www.haltonarp.com/?Page=Forum