Hello, All...

I have read all of Arp's books, and many, many other authors' works.  One thing seems to be brought up much more often than one would think, and that is the lamentation that there ought to be more redshift measurements made of many curious objects.

Without going into the "telescope time" problem, can anyone shed light on this?  Are there any systematic redshift measurements of "interesting objects" going on at the moment?  I haven't been able to find references to any.  Links to any current studies would be appreciated.

Finally, how about some discussion about what would be a good study for redshift measurements.  Yes, of course, the measurements of companion galaxies should be fleshed out, but what about some others?

Regards, Mike Petersen

I think large part of the problem is that redshift studies in general are designed so that you have certain coverage area from where you measure redshifts with even distribution so that your redshift coverage of the area will be homogenous. As you probably realize, this way you don't get much measurements where two objects right next to each other are both measured. Most likely targets in this kind of studies are the brightest objects, so you end up with lot of measurements of main galaxies, but very little of their fainter companion objects.

Another problem currently is the tendency to go for as faint objects you possibly can, so you get lot of studies mapping the z > 2 objects (for example). This, and the problem above leave the companion objects of bright galaxies in between, they are generally too faint to be interesting but not faint enough to be interesting.

Automated studies have also a problem with measuring objects very close to each other in the same run. For example, I think that 2dF had a limit somewhere around 30-40 arcseconds. In that kind of setting you only get measurements of very closeby objects only if you run the same area twice. I think SDSS also has some limit like that one.

But these large automated studies are nevertheless providing us a lot of new measurements. There are also some studies devoted to the redshifts of neighboring objects, but they are quite rare. Some studies also make very thorough redshift mapping on certain individual systems.

A good study from my point of view would be to extend SDSS for nearby objects of bright galaxies. Or, make a redshift study of lot of galaxies and their closest galaxy-like object, or few closest objects. Good big project would be to take all galaxies from the catalog of bright galaxies by de Vaucouleurs and measure their close objects (out to certain distance from the galaxy and with certain brightness limits for the measured object).

What I am working on (which means going to the pub and letting ones mind drift under copious amounts of liquids - theoretical Physics is a great qualification!) and getting absolutely nowhere is 'are the galaxy rotation curves a redshift effect'?
I mean, the curves are flat. That is, as one goes out towards the edge of galaxies the speeds remain constant instead of getting slower.
This is put down to 'dark matter.'

But the speeds are measured by redshift.

So is it just a case that the intrinsic redshift changes as one goes out towards the edge of the galaxy so that the speeds appear to remain the same (hence no dark matter).

I am not having a lot of success with my theory on this (look at how honest I am1) but would anyone else's theory work?

Has anyone tried to look at the flat rotation curves using the Arp-Narlikar variable mass theory?  Perhaps galaxies consist of younger material in the center, and the farther one goes towards the "edge", the older the matter gets.  That would mean that, um, let's see...that would mean the redshift should lower as we move out from the center of the galaxy to its edges.

Is this what is measured?  Or does the redshift increase as we move to the edges?  I am woefully ignorant on this.  Clarification, anyone?

This probably doesn't answer to anything here, but here's one paper relating to the subject:

http://adsabs.harvard.edu/abs/1975A%26A....40..257J

Egad!  That paper is 35+ years old.  Are there no more recent studies?  It would seem to me there ought to be, because the results of this paper were intriguing.  Does anyone think this is another of those areas that are studiously avoided by mainstreamers?  I can't think of any other explanation.

- Mike

I think this is the same as the redshift in the arms of the sun - theyr increase towards the edge. Ari Brynjolfsson did a paper on this and the galactic halo explaining it by his version of Tired Light. It works the same with mine.
http://arxiv.org/abs/astro-ph/0401420
This is not the same as the rotation curves - the speed of the stars in a rotating galaxy should get smaller as one gets out towards the limbs (in our solar system the further out a planet the slower it goes). They don't.
If it is a redshift effect then stars in the galaxy moving away from us in the rotation must experience an intrinsic redshift that gets greater the further away from the galactic centre (so that as they physically slow, the intrinsic redshift velocity component gives the overall retrograde velocity measurement a boost so that the resultant measurement stays the same) whilst stars in the galaxy moving towards us in the rotation must experience an intrinsic blueshift that gets greater the further away from the galactic centre.

Perhaps our doppler redshift equations are a bit wrong. I wonder how high velocities we have used to test those equations. What would result if we assume that galaxy rotation is non-flat, and we would derive our redshift equation from that?