BeAChooser
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Does anyone agree with some, all or none of these points?
That's a reasonable summary of the situation. Glad to see that someone around here is being reasonable.
Does anyone agree with some, all or none of these points?
Originally Posted by Wangler
1) It seems as if a posteriori statistics are used in astronomy perhaps more often than in other technical fields.
However, if we're talking about astronomy and astrophysics, as branches of science, then 1) starts too far from the beginning to be of much help, and so the rest become not so interesting ...
Originally Posted by Wangler
3) With 2) being stated, there are some apparently unique associations between some QSOs and some bright galaxies.
In any case, 3) does not depend on 1) or 2) ... and unless it is much, much more tightly qualified is so boringly, obviously true that we need not waste any more time on it.
Of course, every 'association' between any set of quasars and any set of galaxies (whether bright or not) is unique! What I think you may have intended to say is something about a general pattern, a relationship between a tightly defined subset of quasars and galaxies.
This pattern could be something derived from a theory, such as the non-existent one BAC refers to
However, the whole chain (above) can be short-circuited by asking two, very simple, questions:
a) what is a 'quasar'?
b) are 'quasars' a homogeneous class of objects?
how was NGC 3516 selected?
how many 'near NGC 3516 quasars' were known before Chu et al. planned their observations?
how are quasar redshifts distributed, in [0,3]? If they are not distributed equally (to within some bound), then probability calculations need to reflect that non-equal distribution.
your calculation, on its own, would seem to apply to any set of three numbers in [0,3]
As I noted earlier, if the range is [0,3], then all the Karlsson values in that range need to be included.
Beachooser wrote:
Here's a 2005 study http://www.iop.org/EJ/abstract/1538-3881/129/5/204 that indicates an average density of 8.25 deg-2 based on the SDSS survey then argues it should be corrected upward to 10.2 deg-2 to make it complete. And if you go to the SDSS website (http://www.sdss.jhu.edu/ ) you find they say the effort will observe 100,000 quasars over a 10,000 deg2 area. That also works out to about 10 quasars deg-2. So it looks like I used a number that was 3 times too large in my earlier calculation. In this revised calculation, I will only assume the average quasar density is 10 deg-2. That means the total number of quasars than can be seen from earth is around 410,000.
The Chu et al. paper carefully explains how they chose which objects to observe (in order to measure redshifts); the "average density" of quasars you need to use in this part of your calculation is that which would be obtained if the search method used in Chu et al. were to be used over the whole sky. As there appears to be no effort to explain this, in any quantitative fashion, let alone estimate it, you are left with an unknown.
No, I don't. The results of my calculation are not affected by the fact that more quasars might be located in one little area of the sky than in another, as long as the average density of the entire sky is 10/deg2. The total number of galaxies with 5 or more quasars (or 2 or 3 in the later calculations) near them will remain the same. Somehow, I think you aren't conceptualizing the true nature of this calculation.you need at least a measure of the variation in average density (as well as the average density), to make the sorts of estimates this part of calculation aims to do.
Do you honestly think that more than half of quasars lie near low redshift galaxies? Care to prove that? Do you have ANY basis for thinking that? The fact that Arp could only come up with a limited number of anomalous associations, after studying what must have been thousands of cases, seems proof enough that more than half of quasars must not be near low redshift galaxies from our viewing perspective. But I tell you what, if you have evidence that the percentage is higher than 0.5, then just offer it. Don't be coy. We can factor that into the calculation of probabilities and see what happens. :) Or maybe there's another way we can come up with an estimate of the number of galaxies we need to consider as being near quasars. What we need to know is the number of galaxies that are low redshift ... say within a redshift of about 0.01 (since both of the cases in my calculation have redshifts less than that value). ThisBeAChooser wrote: But the truth is that most quasars do not lie close to galaxies at all (certainly not galaxies where we can discern any detail as is the case in all three examples of interest here) so that's why I later multiplied the calculated probability by 0.10 to account for the assumption that only 10% of quasars lie next to a galaxy. I still think that's probably a reasonable number. But for this calculation, I'm going to give your side the benefit of the doubt and assume that fully half of all quasars are near galaxies. That has to be very conservative. Wouldn't you agree. So now there are 205,000 in the population that we need to distribute amongst galaxies. Making up numbers, and using one's intuition about what's conservative, reasonable, etc, in astronomy is an almost certain way to be wrong.
Are you saying I should use their estimate for the average quasar density per square degree of sky? Or their estimate of what fraction of the quasars are actually within a degree of galaxies? Or their estimate of what fraction are in quasar/galaxy associations with 5 quasars per galaxy? Did they actually estimate any of those numbers? I don't recall seeing it in the paper. If you see those numbers, please point them out to me.Earlier you introduced a paper by L-C&G, which presented some rather concrete numbers of just what you are trying to estimate; why not use what's in that paper?
A series of posts on questions that remain unanswered.
They also go on to show absorption lines, and reddening of the QSO, both indicative of some sort of matter between us and the QSO.
Spiral galaxies are not that dense in their rotational plane, even this close to the nucleus.
I think that the evidence I see points to the QSO being at the distance indicated by it's redshift.
Then I must have misunderstood your "hosts of gnomes" objection to the dark matter observation in the Bullet Cluster. It was not referring to the dark matter, it was just the one gnome about the distance to the Bullet Cluster as measured by redshift.
I am not an expert in statistics but I will look at your calculation about "improbability of so many redshifts in quasars near certain galaxies that are close to the Karlsson values". It looks plausible at first glance but so many statistical calculations do and many posters seem to disagree with the calculation.
As for NGC 7319: The quasar looks as if it is shining through the galaxy.
But galaxies are not solid
However it is unlikely to be in front of the galaxy since the Pasquale Galianni, et. al. paper states that the QSO spectrum has absorption lines in it consistent with the gas in the galaxy.
and that I may not be able to post for a couple of days or so ...
The full posting I "misrepresent" is here and is actually about this topic. The applicable paragraph is:Again, another misrepresentation of what I quite clearly stated. That's why I'm not going to go back and address this issue with you, RC. It makes no difference what I actually say, you will just misrepresent it.
I was under the impression that a host was more than one.David and his friends on this forum like to go on and on about dark matter being directly "observed" in the case of the Bullet Cluster ... even though there are a host of gnomes and assumption based calculations implicit in that so-called observation. Yet, the 2003 discovery of a high redshift (z = 2.11) quasar that is visually (in ordinary light) between us and the dense core of a low redshift (z = 0.022) galaxy, NGC 7319, is just dismissed out of hand.
The full posting I "misrepresent" is here and is actually about this topic. The applicable paragraph is:
I was under the impression that a host was more than one.
The Keel papers do show that spiral galaxies tend to be optically opaque along the arms and near the nucleus and so this quasar should not be visible. The key word is "tend". We have found optical holes in our own galaxy. It may be that this quasar is visible through such a hole. I am not ruling out that this is a real phenomenon and agree with the authors of the paper that more study is needed.
One quick comment,,,
You may beable to pass off one as a mere co-incidence, but, for example, Galaxy NGC 7603 has two definate small quasar like objects clearly at both points in the plasma filament connecting the quasar to the galaxy. Both have very different Redshifts.
Theres a picture of it about twenty seconds into this documentary, with various astronomers talking about it;
http://www.youtube.com/watch?v=EjQVybreSUs
Rather than look at what is probably a one-sided documentary judging by its description I went straight to an applicable paper: The field surrounding NGC 7603: Cosmological or non-cosmological redshifts?One quick comment,,,
You may beable to pass off one as a mere co-incidence, but, for example, Galaxy NGC 7603 has two definate small quasar like objects clearly at both points in the plasma filament connecting the quasar to the galaxy. Both have very different Redshifts.
Theres a picture of it about twenty seconds into this documentary, with various astronomers talking about it;
http://www.youtube.com/watch?v=EjQVybreSUs
.That's not true. I have no problem with baryonic dark matter. I've said that many times.
And it's because certain posters keep mischaracterizing what I actually said that I choose to ignore some of the efforts to debate me on certain threads after basically everything has been said that needs to be said and after I've been repeatedly insulted on those threads. So if I wish to discuss dark matter then I will visit that thread you mentioned. But I would appreciate your confining your remarks on this thread to the matter of redshift and observations that suggest redshift might not equate to distance in all objects. For example, would you like to comment on my calculation regarding the improbability of so many redshifts in quasars near certain galaxies that are close to the Karlsson values? Or do you have something to add regarding NGC 7319 and the quasar that appears to be on this side of it?
.In other words, a desperate attempt to obfuscate your growing problelm on this thread? Perhaps we should stick to the calculation I offered until you convince everyone there is no problem? If you can't, perhaps then we can focus on identifying a viable alternate solution.DeiRenDopa said:A series of posts on questions that remain unanswered.![]()
.That's ok. I'm feeling the pressure of tax time too.![]()
.The full posting I "misrepresent" is here and is actually about this topic. The applicable paragraph is:BeAChooser said:Again, another misrepresentation of what I quite clearly stated. That's why I'm not going to go back and address this issue with you, RC. It makes no difference what I actually say, you will just misrepresent it.David and his friends on this forum like to go on and on about dark matter being directly "observed" in the case of the Bullet Cluster ... even though there are a host of gnomes and assumption based calculations implicit in that so-called observation. Yet, the 2003 discovery of a high redshift (z = 2.11) quasar that is visually (in ordinary light) between us and the dense core of a low redshift (z = 0.022) galaxy, NGC 7319, is just dismissed out of hand.
I was under the impression that a host was more than one.
The Keel papers do show that spiral galaxies tend to be optically opaque along the arms and near the nucleus and so this quasar should not be visible. The key word is "tend". We have found optical holes in our own galaxy. It may be that this quasar is visible through such a hole. I am not ruling out that this is a real phenomenon and agree with the authors of the paper that more study is needed.
.I guess I believe the verdict is out and what makes me uncomfortable with Big Bang is that one phenomena after another is being explained only via bizarre particles, forces, energies and interactions that we haven't been able to demonstrate or see in a lab here on earth. At this point they are purely mathematical constructs.
.
...
Dancing David clearly wants to stick to why he started this thread in the first place (and the paper on NGC 3516 would fit nicely within that scope, I think).
And I would like to have the unanswered questions in post 207, 208, and 209 answered.
However, at some point I think we should get onto the question of what a quasar is; if we don't I feel this thread will grow much longer.
.One quick comment,,,
You may beable to pass off one as a mere co-incidence, but, for example, Galaxy NGC 7603 has two definate small quasar like objects clearly at both points in the plasma filament connecting the quasar to the galaxy. Both have very different Redshifts.
Theres a picture of it about twenty seconds into this documentary, with various astronomers talking about it;
http://www.youtube.com/watch?v=EjQVybreSUs
.Rather than look at what is probably a one-sided documentary judging by its description I went straight to an applicable paper: The field surrounding NGC 7603: Cosmological or non-cosmological redshifts?
This observation is almost enough to convince me that anomalous redshifts exist and so distances determined from some QSO's are in doubt. I would like an independent observation, preferably at a higher resolution so that any structure of the alleged QSOs can be determined.
IMHO, If this observation is confirmed it will cause as many problems for cosmologies including "intrinsic redshift" as it will for conventional cosmology.
If these 2 quasar-like objects (and NGC 7603B?) were ejected from NGC 7603 in one ejection event then why do the quasar-like objects have different intrinsic redshifts?
If they were ejected in separate events (i.e. have different ages) then why is there an identical direction of ejection?
