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Previous Next Up Topic Cosmology / Alternative Cosmology / Lopez-Corredoira: Summary paper on QSO-galaxy associations (2995 hits)
By Ari Jokimäki Date 2009-01-29 06:06
There's a new paper from Lopez-Corredoira in arXiv today:
Apparent discordant redshift QSO-galaxy associations

There's nothing new there, it's just a (nice) summary of the subject.
By Jade Annand Date 2009-01-29 20:00
That is a nice summary.

I like in particular Martín's treatment of the way people treat the problem: the casual dismissal of the problem, the sloppiness of some of the non-cosmological/alternative redshift proponents, and the very non-sugar-coated statement:

Martín said:

Mainstream cosmologists are waiting for the death of the main leaders of the heterodox idea (mainly Arp and the couple Burbidge) to declare the idea as definitively dead.


Martín points out:

Martín said:

There are, however, many papers in which no objections are found in the arguments and they present quite controversial objects, but due to the bad reputation of the topic, the community simply ignores them.


It will be a mistake to think that the ideas will die right along with them, of course, since we already know there are quite a few minor players in the field who are unlikely to let this go, and the observations are getting up to higher redshifts, which we have already seen results in some violated expectations for concordance cosmology. Did Arp and the Burbridges really have that much influence?

I did get a laugh out of his encounter with people who figured that since something already happened, its probability of happening was 1.0, and therefore there is nothing to see :)

Thanks for the link, Ari!
By David Russell Date 2009-01-30 00:36
I read the paper over.   As you said, nothing really new, but it is a good reminder of what we've been looking at.   I think that the large SDSS data releases have actually made the problem of QSO distances harder to analyze.   When Arp started, there were only a small number of very bright, radio loud QSO's.   The apparent associations with large, bright, local AGN was fairly compelling.  However, as the surveys go to much fainter objects, it becomes more difficult to identify the parent galaxies to the QSO's because the number of candidates increases exponentially.   Fainter QSO's will be associated with more distant parent galaxies which means you're looking for fainter parent galaxies and therefore many more candidates.  This was a point some people on BAUT never seemed to understand.   I think it is time to reanalyze the QSO distributions focusing on objects brighter than a certain limiting magnitude.  

But in the meantime, bridged associations from our M51 catalog need to be studied in more detail.
By Ari Jokimäki Date 2009-01-30 06:03
Yep, "non-sugar-coated", my thoughts exactly. :)

Dave said:

I think that the large SDSS data releases have actually made the problem of QSO distances harder to analyze.   When Arp started, there were only a small number of very bright, radio loud QSO's.   The apparent associations with large, bright, local AGN was fairly compelling.  However, as the surveys go to much fainter objects, it becomes more difficult to identify the parent galaxies to the QSO's because the number of candidates increases exponentially.

There's another problem that at least 2dF QSO catalog has; there is a maximum limit for magnitude of the objects, so 2dF QSO catalog selection criteria excludes bright quasars, so it is not best possible catalog to look at this issue. I don't know if this is a case with SDSS also... oh, it seems that at least DR5 QSO catalog has maximum magnitude limit (I-band PSF magnitude > 15).
Previous Next Up Topic Cosmology / Alternative Cosmology / Lopez-Corredoira: Summary paper on QSO-galaxy associations (2995 hits)

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