Hey there Danny and Elsewhere, don't stop now. I'm quite enjoying your back and forth tete-a-tete.
Have to sleep sometimes, we ahave some time difference :)
I was not successful in identifying the points of light surrounding the primary object, and therefore could not comment on their respective distances either. I looked at literally dozens of sites to find such info and nothing shed any light on this. Perhaps you could enlighten me and the rest of us.
Because we are in our galaxy with lots of stars in each direction that you look you will find stars (not in each direction a equal amounth by the way) So the points of light are very probably all stars. Maybe one or two could be other galaxies, but they have a more fuzzy form. It is easy to examine if it is a star when you use a spectroscope. You can see what the star is made of and the temperature of the star. A spectroscopic analysis can always show if it is a single star or a whole galaxy of stars. You do not need the redshift for this.
See my picture of the Andromeda. There are two satelite galaxies, but it is clearly that they differ from the stars. Stars are more pointlike.
Danny, if you look to Velocity (Redshift) as an explanation, are you suggesting that if a quasar appears to be in front of a galaxy (nearer), and the galaxy has a lesser redshift, that therefore it is because the galaxy is travelling at a lesser velocity away from us, and so we get this lower reading? And therefore, the implication is that the quasar could still be farther away?? Please clarify what you are suggesting.
I do not really suggest this, as I do not think it is very likely.
First of all, from this and some other examples it seems that there is a connection between some quasars and some normal galaxies. There is also some support of this in observations made in radio wavelengths.
So this quasar is not in front or closer by then the galaxy, it is near the galaxy, and has about the same distance. So probably at least a few others.
Anyway, we have to ask if the red shift of the quasar is so high, and it is closer than expected, then what other process gives the quasar the red shift.
A possibilty is that it is moving away from us. Red shift is speed, this can be speed due to expansion of the universe or actual speed of the object. So if this object is moving for some reason at half the speed of light away from us, it would give this result in observation.
However I can not see any reason why this object whould travel so fast. So I don't think this is a good explanation, but it is a possible one however.
The second thing is that red shift can also be caused by gravitational pull. If this quasar is a very compact heavy object, its radiation would have a redshift even if it is not moving. So this could explain it.
There can maybe also be another process at atomic scale, causing a red shift.
Does this invalidate the relation between red shift and distance. No, not at all. This relation is shown to exists. It proves that there are maybe other factors, specially in quasars that have to be included in this relation. It can also mean that some or maybe all quasars are not as far as we though.
An anology: There is probably a relation betwen the temperature of the tires of a car, and the speed of the car. (in equal conditions, same kind of cars etc). Supose you have a formula for this (probably a notr very simple one) and it allows you to calculate or estimate the speed my measuring the temperature.
Now we see a motorbike come along and messure that the speed by the temperature of the tires. But this motorbike is traveling alongside a car, and we estimated of course a very different speed. The motor is lighter, different tires etc.
So what is our conclusion now: Cars do actually not move (there was no big bang) or the relation seem to be more complex and in case of cars it works out find, but in case for a motorbike we need to add some things?
Danny