It has been explained in "More from Arp et al" thread (link to that thread was given in this thread earlier) many times that quasar host galaxies are not a problem for a local quasar model, at least for Arp's model anyway, first time it is explained in the first page of that thread, in post #7.

-------------------

Claim that Scranton et al. study shows Arp's work wrong has also been refuted in that same thread many times (for example in page 47 post #1410, page 49 post #1460, page 50 post #1494, page 51 posts #1504, #1514, and #1527, page 52 post #1553).

__________________
"Stupidity gets denser in a crowd" - Old Finnish saying. [My website and My BLOG] [Nimblebrain forums]

I don't believe that is an adequate explanation. Looking at the paper that is cited in that post #7 it doesn't talk about quasar host galaxies at all. It looks like he's talking about "companion" galaxies. What is meant by quasar "host" galaxies is that when you take an image of a quasar, you often see that is in fact in the center of a small (i.e, distant) galaxy.

But seeing that much of this ground has been covered in the other thread there's not much point in continuing to beat this dead horse.

That is what I meant by "host galaxies" as well. In Arp's model, the ejected matter from active galaxies is first in form of cloud of particles which then condenses to form a quasar. It is unlikely that all the ejected particles end up into the quasar, so you get a quasar that is surrounded by a cloud of particles. Later that quasar surrounded with particles will evolve into a galaxy having the quasar as nucleus and the surrounding cloud as the disk of matter.

Quasars with host galaxies are expected in Arp's model.

__________________
"Stupidity gets denser in a crowd" - Old Finnish saying. [My website and My BLOG] [Nimblebrain forums]

I call to your attention a little known paper, which was eventually published in the Publications of the Yunnan Observatory 90(2): 16-21, 2002 (or so I assume since the titles are the same, although only Qin & Liang authored the Yunnan version): Evidence consistent with the cosmological interpretation of quasar redshifts, Qin, Xie, Zhen & Liang, 2000.

Abstract: In this letter, the old issue of whether redshifts of quasars are of cosmological origin is investigated. We make a plot of absorption redshifts versus emission redshifts for quasars with large amounts of data. Our study shows that, almost all absorption redshifts are smaller than the corresponding emission redshifts. The relation between the absorption and emission redshifts predicted by current cosmological models is well obeyed. The result confirms that redshifts of quasars are indeed distance indicators. It might be the most obvious evidence found so far to be consistent with the cosmological interpretation of quasar redshifts.

You can see from the paper that the higher redshift quasars, which are at larger distances in the standard models, have more Lyman-alpha absorption lines than to lower redshift (closer) quasars. Furthermore, it is very rare to find an absorption line at higher redshift than the quasar, and in all such cases, the difference is very small, consistent with the higher redshift absorber being associated with the host galaxy. If we simply assume that the absorber is somewhere between the quasar and us, surely a reasonable assumption, then it is indeed hard to avoid the conclusion that the quasar redshift is a valid indicator of cosmological distance, as opposed to being in any way intrinsic to the quasar.

You suggest that the redshift is always smaller because the absorber is influenced in some way by the quasar or the host galaxy. Do you have any specific mechanism(s) to suggest?

__________________
The point of philosophy is to start with something so simple as not to seem worth stating, and to end with something so paradoxical that no one will believe it. -- Bertrand Russell

Thank you parejkoj, Cougar, Nereid and Amber Robot. I have been accessing all the references you mentioned and appreciate the leads.

I don't think that Arp thinks that quasars are anything other than young galaxies, so the idea of being at the centre of a galaxy does not seem strange.

OK, I went there and it referenced a page about 200,000 quasars can't be wrong. Unfortunately the article makes the claim that quasars will be brightened by gravitational lensing but doesn't really explain the method. According to my logic, if you make some part of the distant sky brighter by expanding it, you must make some other correspondingly part dimmer by contracting it. It is a simple fact that the totally area of the sky must be conserved by the lensing. So why would quasars be brighter on average?

If Arp is right that quasars have an "internal redshift" (in other words are much closer than expected) then you would not expect quasars to have intervening absorption at greater redshift. So that does not provide evidence in favour of the cosmological redshift at all. But I didn't start this thread to try and debate this, but to do my own analysis to test it because I want to be sure myself what is correct.

The very large scatter in the quasar redshift versus brightness diagram is a reason to suspect that redshift accurately measures distance. Of course it might be that they really have a huge range of brightnesses. One other thing that I would like to do with a quasar survey is to look at the various properties of quasars, particularly any parameters that might be indicative of their age, as that would be correlated with intrinsic redshift if Arp is right.

What survey would be best to use that has most other measurements of quasar properties (e.g. colour indices, other emissions, etc)? It does not matter if the sample size is not great as long as they are reasonably representative.

The idea is to see whether it is possible to make an estimate of their intrinsic redshift and produce a much tighter external redshift (being observed minus estimated internal) versus brightness diagram like for galaxies.

I think that if the scatter can be considerably reduced then that would be proof of a non-cosmological component to redshift.

Have you ever looked at an image of a quasar host galaxy? See, for example this link. If these are not at cosmological distances then there is a completely new type of galaxy that is very different than every other type. When you look at these images you can sometimes see fully-blown spiral galaxies, If these are not at cosmological distances, and are at local distances, then they are very, very small. And then you have to explain why the redshift-distance correlation should not apply to these galaxies like they do for other local galaxies.

(my bold)

Do you have some equations (maths, numbers, and stuff) to support this?

Specifically, what mechanism (or class of mechanisms) are you assuming is doing the brightening, expanding (and dimming, contracting)?

Would you please clarify something?

In this ATM thread, are you presenting (and defending) your own ATM idea, Arp's ideas, or something else?

One reason why I'm asking is that, as I pointed out earlier, there is an old ATM thread on Arp's ideas.

My own, Arp's and Narlikar's and some of Tifft's (his early observations but not his theory). I started this because the previous quantized redshift thread was closed.

Quite simply, the size of the sky is equal to the size of the sky. So if you have a complicated lens over it, whatever parts get magnified, some other part gets shrunk to exactly compensate.

But I think I got the answer thanks because although the popularized article is very weak, the journal article is not. It does explain that it is based on the nearness to the galaxies.

Yes, they are new type of objects, they are intermediates between quasars (which in Arp's model also are new type of objects) and galaxies. If there is a spiral galaxy in the making, then I don't see any problems in spiral structure being already visible, at least not in principle.

Redshift in Arp's model is "More from Arp et al" stuff but briefly, redshift decreases with age of objects and quasars are newly created objects in Arp's model. But, if one starts to argue against these local quasar models, one should already know these basic issues about them, no? (Similarily, if I would argue that Big Bang theory doesn't work because it puts Earth in the center of the universe, or some other clearly false argument, then surely you would suggest that I should learn about Big Bang theory before arguing against it.)

__________________
"Stupidity gets denser in a crowd" - Old Finnish saying. [My website and My BLOG] [Nimblebrain forums]

I'm aware that that my contribution to this discussion is absolutely insignificant, but I can't help noting that the (in)famous ATMers mantra "...look at the picture!" is well rooted amongst the mainstreamers too, and no one does complain about it.

I apologise to Amber Robot and Ari Jokimaki for my impolite break into their discussion.

My suggestion to "look at the picture" was to point out that the quasar host galaxies look like distant galaxies. And that there are no local analogues to these galaxies that don't contain quasars. After looking at the picture, you should look at the spectra, analyze their redshifts, metal contents, ionization structure, star-formation histories, and stellar populations. All of these will give you some clue as to whether these are local objects or not.

I am not explicitly stating that quasars aren't local objects spat out of galaxies and creating mini-spirals, I'm arguing that you can't make that the statement that are local based solely on their relative positions to nearby galaxies. There is a virtual cornucopia of spectral and photometric information about the quasars themselves and their host galaxies that need to be taken into account and formulated into a coherent picture of what these objects are.

Well, if you consider "redshift decreases with age of objects" as a "basic issue" of quasars then you're right that I don't know that, because that is also part of Arp's model and not an already established fact one must "learn about" before arguing against Arp's model.

When I said "basic issues about them", the "them" referred to models, not quasars. My point was simply that if one doesn't know about these models and one wants to discuss them, then one should start by asking questions about the models in order to learn about them. One should not start by claiming that the models don't work because of this and that if there's no actual knowledge how the this and that work under the models in question.

__________________
"Stupidity gets denser in a crowd" - Old Finnish saying. [My website and My BLOG] [Nimblebrain forums]

Fine. Then my question is this: How does Arp explain damped lyman alpha systems in his model?

Don't get so nervous, Amber Robot, I posed only a question of method.

But, as you turned it to merit, I would like to ask if you do think that a layman has to content himself with this assertive statements about quasars (read here; some my bolds added):
Or may any issue on quasars be posed only on the right side?

Yes, the popular press, and the popular scientific press also, present too much as absolutes when they should be qualifying. And they go to the other extreme also, and qualify where they shouldn't. The K-T impact is a fine example. Boom, done. And paleontologists as good as Bakker go hand waving about disease and climate. Certainly one of my pet peeves.

I agree with John that most astronomical press releases present far more certitude than is warranted. Would you feel better if it read: "Astronomers theorize that quasars consist of supermassive black holes, each surrounded by a vortex of gas."? What level of proof is needed before a statement can be made without such a preface?

How do you feel about the certitude of the following statements? How many need a "astronomers theorize that..."?

- there's a supermassive black hole at the center of the Milky Way.
- the moon orbits the earth.
- the Andromeda nebula is a galaxy, not unlike the Milky Way, that is 2 million light years away.
- type Ia supernova are caused by white dwarfs accreting matter beyond the Chandrasekhar mass limit.
- the age of the universe is 13.7 +/- 0.2 billion years old.
- in the ultraviolet, dust is highly forward scattering.

Certainly more than one side should be viewed on the question of quasars. But at what point does one side become the dominant paradigm? At what point should it? At what point do Arp's ideas become a historical curiosity? Is it possible that the rest of the astronomical community has gotten it wrong and Arp has it right? I guess that is possible. I don't think, though, that most astronomers think conspiratorially about their theories. Egos do get involved sometimes, of course. And that applies equally to Arp, too.

Can I (neither de-, nor re-, so just...) rail the conversation here for a moment? I think everyone in this conversation needs to answer the following:

We can't talk about these things without agreeing on a definition (or at least being aware a of what we each are talking about). I'm speaking of an observational definition, not what you think they physically are. Please give me a set of criterion for separating quasars from not quasars. If you want to cite a paper, that's fine, but also describe the definition, briefly.

rtomes: If it is the working definition you are using, can you paraphrase the what SDSS defines as a QSO?

Ari Jokimaki: Could you please tell me what you and/or Arp et al. define as a quasar, observationally? I haven't seen it defined in the few of their papers that I've read.

__________________
"What do you care what other people think?" -- Richard Feynman
"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." -- Feynman, at the conclusion of his Challenger report

Sorry, I don't know that. That's why I originally commented only your quasar host galaxies claim.

__________________
"Stupidity gets denser in a crowd" - Old Finnish saying. [My website and My BLOG] [Nimblebrain forums]

My definition: Stellar looking object that has high redshift (say, roughly z > 0.1).

Arp's definition, or rather, my rough interpretation of it: Stellar looking object that is newly created and has been ejected out of active galaxy. (In Arp's model "newly created" means it has high redshift, and having been ejected out of active galaxy means that generally quasars are much closer than their redshift distance indicates, because they are associated with the low redshift active galaxy.)

__________________
"Stupidity gets denser in a crowd" - Old Finnish saying. [My website and My BLOG] [Nimblebrain forums]

Dwarf galaxies at redshift >0.1 can look stellar! How is the "stellarity" of an object defined?

Thank you, it's just what I intended stressing on.

The problem lies in the fact that this "astronomy-by-press-release" style not so seldom leaks out to scientific press too (as good old "Chip" said in one of his so hurting pamphlets), and astronomers don't dislike it.

Regards.

Note that it was only my "definition", which is intentionally vague, because currently I don't really know what these objects are (I haven't really decided if I believe Arp, or believe him partly, or if I don't believe him at all). I took the value 0.1 out of my hat, it was just to give some idea what I meant by high redshift, and I think that generally the lower limit for QSO redshifts are somewhere around there.

I haven't really thought what "stellarity" would mean in this context. For example, if Arp would be correct in that quasars would be recently created objects made of low mass particles, then I don't think they necessarily would look like tightly packed "stellar" objects if you are observing them close, they might indeed look like dwarf galaxies.

__________________
"Stupidity gets denser in a crowd" - Old Finnish saying. [My website and My BLOG] [Nimblebrain forums]

That's quite satisfactory for me, crammed as it is with questions and so few certainties.

I seem that some of the statements you posed are no longer debated, and this may signify that scientists have reached a reasonable certitude, here.
May be that, on the contrary, some others are involved in ego issues, but nevertheless they are worth a scientific debate, rather than an aprioristic rebuttal of any "un-orthodox" hypothesis.

Perhaps, the "conspiration tale" (which I don't believe), is nurtured by hypertrophic egos on both sides.

Now it's better for me to retire, so I'll not interfere with this interesting discussion.
Thank you, anyway, for your kind reply.

Side note: z > 0.1 isn't considered particularly high redshift these days, and SDSS has hundreds of objects that it calls QSOs (classified spectroscopically) with redshifts below 0.1.

Nothing wrong with a vague definition. "Stellar-looking object" was the classical definition for a while after they were discovered, but it has plenty of problems if you try to pin things down: Do you mean an object that is a point source photometrically? In all wavebands, or just optical and to what level of resolution? Look at anything with high enough resolution and it won't look like a point source any more! What about the spectrum? It should probably look non-stellar, but how? What exactly distinguishes something that is "stellar-looking" from an actual star, besides proper-motion (which is hard enough to measure in stars themselves)?

For example, which of these would you consider a quasar? (remember, the automatic computer-based classification in SDSS isn't always correct).

http://cas.sdss.org/dr6/en/tools/exp...98663046938695
http://cas.sdss.org/dr6/en/tools/exp...97863112294442
http://cas.sdss.org/dr6/en/tools/exp...97863112294443
http://cas.sdss.org/dr6/en/tools/exp...35348562624561
http://cas.sdss.org/dr6/en/tools/exp...24232638464033
http://cas.sdss.org/dr6/en/tools/exp...25550136786984
http://cas.sdss.org/dr6/en/tools/exp...34691424895079
http://cas.sdss.org/dr6/en/tools/exp...22983903985955
http://cas.sdss.org/dr6/en/tools/exp...24241235017792

They are all interesting objects, to say the least. But are they quasars? (I've got plenty more where these came from! ) Some of them are quite stellar-like...

That's a model for quasars, not an observational definition. What I want to know is, can you (or Arp, et al., or Narlikar et al. or rtomes) tell me something is a quasar just by looking at it (or its spectrum, or its radio or x-ray or UV properties or something else about it), based on some defining characteristics? Not an easy question, I know; I can't always identify quasars immediately myself, but my definition is rather fluid, encompassing a fairly broad range of objects. And I'm no-where near an expert.

Kinda like defining "planet."

__________________
"What do you care what other people think?" -- Richard Feynman
"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." -- Feynman, at the conclusion of his Challenger report

Thanks for the info. I guess I included high redshift to my definition just to distinguish quasars from low redshift galaxies they are claimed to be associated with, and which generally have much lower redshift than 0.1 (there are exceptions too, such as 3C 343 where the "galaxy" has z = 0.34 and the "QSO" has z = 0.75).

Yes, and as I'm not knowledgeable enough to pin things down, my definition will necessarily be vague. And my answers to your questions will only be guesses.

Possibly. I mean an object that generally looks like point source in our images, such as DSS-images, but might deviate from point source in our better images, such as HST-images. If you mean that by "photometrically", then yes. But I guess you can do some fancy tricks with photometrics, so might it even be possible to detect them as non-point sources even from DSS-images (for example)? Does luminosity profiling belong to "photometrics"?

My definition is about visible appearance, but then again, you can't really discriminate QSOs from all objects with my definition. (And my definition doesn't carry any wieght, so it is not even very important for this discussion.)

True. (Although I'm not quite sure if you can say that about individual photons. )

Well, it's probably here where most of the real definition lies. I really should learn about spectroscopy...

Beats me. For example SDSS have had some trouble with stars masquerading as quasars.

But if local quasar models are correct, then you'd expect to see proper motion in some quasars that are associated with some nearby galaxies. Or, it depends on local quasar model, but in Arp's model quasars are expected to have high velocity due to being ejected from nearby galaxy, so proper motions would be detectable in some of them. But they probably would still be less than the proper motions in many of the stars in our galaxy.

Yes, I know that. I have spent enough time at SkyServer to have noticed that myself. For example, apparent HII regions in galaxies are quite frequently mentioned as quasars, faint quasars, or stars.

Not a quasar. I would say this is quite ordinary galaxy. But click the image in that page and you'll get finding chart image of the same object. There are three blue objects that I would consider quasar candidates, they are at 6, 9, and 11 o'clock from your object.

Perhaps could be a quasar, but quasar wouldn't first come to my mind when looking at this object.

This is slightly worse quasar candidate than the last one in my opinion. I think it has to do with the brightness of the nucleus.

A spiral galaxy, not a quasar.

Also a spiral galaxy.

I don't know what I would say to this if I wouldn't know these are SDSS images (I think I would accept this as a quasar candidate). So far the quasars I have looked at in SDSS images have been blue (to my recollection). I think this is a star in our galaxy. (And the redshift reveals that it most likely isn't a quasar.)

Could be a quasar, but to me it is more likely to be a HII region.

Not a quasar, a galaxy.

Quasar candidate. Quasars look exactly like this in SDSS images.

I can't do that currently, but I'm quite sure that Arp for example can (as well as anyone else). But here we approach a question I have though about many times; is there a difference between the objects Arp says are quasars associated with quasars and the objects generally classified as quasars. In other words, is there two classes of quasars in this sense? Are Arp's "quasars" special class of objects?

Definitely not easy, for me anyway.

__________________
"Stupidity gets denser in a crowd" - Old Finnish saying. [My website and My BLOG] [Nimblebrain forums]