The EU myth re quasars (and Arp)
To refresh our memories, here's what Z wrote, in
post #1948:
Zeuzzz said:
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 as being "statistically insignificant", along with all of Arps other observations. Where he has documented well over thirty similar cases, probably even more.
One thing we could do is ask Z for clarification of his statement - where was this '2003 discovery' published, what is his source for claiming that it "
is just dismissed out of hand as being "statistically insignificant"", is it true that "
all of Arps other observations" (bold added) have been also "
dismissed out of hand", and so on - and if Z follow his usual track record he will vaguely answer some of these requests for clarification, after a week or more, and not answer others, and we'll learn that his original claim was a wild exaggeration, etc, etc, etc (IOW, Z has plainly demonstrated, over hundreds of posts, that he is an unreliable reporter of the work of scientists).
However, that would not stop him - or others - making similar claims in future, perhaps in other threads.
Better, let's look at 'quasars'.
In an earlier post I briefly described what the classification of astronomical objects involves, how the classifications are developed, etc.
For our purposes, now, we may consider an astronomical object as a 'quasar candidate' if it is a point source in the visual waveband (or UV or IR) and has a colour* that falls in a certain region of a multi-dimensional colour space; it becomes a 'quasar' if its spectrum shows a redshift of >0.01 (or some other minimum).
That is a purely empirical description ... as long as you don't reject any part of the modern physics textbook, I think we can all agree, can't we?
So, with this definition in hand, we can go look at the sky, and discover quasars; and, being astronomers, we will report, or publish, our observations and somehow they will all end up in one or more of the online databases.
And those databases are, for the most part, freely available, and free ... so anyone - Z, BAC, Arp, ... - can download them and do analyses.
One analysis we can do concerns the distribution of quasars, 'on the sky'; another concerns the distribution of quasars wrt galaxies; another concerns how the number of quasars varies as the database is sorted by colour, by redshift, by apparent magnitude, by ...
Now these sorts of analyses have been done, by the thousand, and form the basis for hundreds and hundreds and hundreds of published papers.
And on the basis of these - and hundreds of other studies, analyses, etc - over several decades, a unified model emerged, that 'quasars' are 'AGNs' (active galactic nuclei). Further, quasars differ from Seyfert galaxies only in degree, not kind; they differ from 'type 2 quasars' only by viewing angle, and so on. Further, this unified AGN model lead to a great many new hypotheses, concerning quasars, ULXs, galaxies, .... which could be tested using observations from Spitzer, Chandra, XMM-Newton, Fermi, and so on (even
Auger!).
Now comes the killer point.
If you wish to make a case that
this quasar is 'in front of'
this NGC object, you need to either show that
this quasar is different from the ~million other ones, OR that all the ~million other quasars are also at distances from us that are radically different from their estimated Hubble flow distances!
IOW, that there are at least two quite distinct classes of quasar (despite the extensive research which shows they are a single class of object) - one that is 'local', and the other which is 'cosmological'; OR that all quasars (and all other AGNs) are 'local'.
AFAIK, no one has, in a published paper, tried to make the former case.
And only a few people try to make the latter case, Arp among them.
Now of course, Arp et al. may be right ... but if so, then no only are all quasars 'local', but also the Hubble relationship is an illusion!
There's certainly no doubt that many an EU proponent claims that the Hubble relationship is, indeed, an illusion (i.e. that galaxies' redshifts do not reflect the Hubble flow and thus cannot be used to estimate their distances from us); however, they fail dismally in their attempts to provide an alternative explanation (I explore this in considerable detail in the
Alternatives: Cosmological redshift/BBE thread, particularly in posts
43,
54,
72,
80,
82,
86,
89,
90,
105,
108,
110,
116,
125, and
132).
So, far from Arp's observations being "
just dismissed out of hand as being "statistically insignificant"", they have been subject to a great deal of scrutiny - especially in the 1960s and 1970s - and found seriously wanting, especially wrt the statistical analyses presented in the paper he (and colleagues) published.
To wrap up: in a world where astronomy caught the quantitative revolution many centuries ago, quasars are AGNs at distances that can be estimated from their redshifts and the Hubble relationship; to those for whom the quantitative revolution has yet to arrive, quasars can be anything you want them to be, provided you write nicely.
*
this is a technical term, and has a precise meaning; suffice it to say that it is a quantitative description of broadband features of the spectrum of the object
!).
