Could the quasar be so close to the galactic center that its orbital velocity could be contributing to the observed red shift.
No, I don't think that's possible. It would have to be orbiting at relativistic velocities, so the orbital period would be extremely short (hours or minutes).
Or could it be an infall of matter that is creating the red shift, yet the quasar is moving at the same rate as the ost galaxy?
First of all, this object is much brighter than a star, so we're talking about a heck of a lot of matter.
Second, it wouldn't all be falling from the same direction; we'd see the blueshifted matter falling in from the other side, and the unshifted matter falling in from every other direction.
Third, infalling matter doesn't just, well, fall in. Almost every falling piece of matter has some non-zero angular momentum with respect to the gravitating object, which means it will try to go into orbit about the object. Now, objects are falling every which-way, and all of that stuff--mostly gas and dust--is going to crash into the other stuff that is in intersecting orbits, and almost all of that angular momentum is going to cancel.
Not all of it, however. After all the cancellations, all of the matter remaining in orbit has an angular momentum that points in the same direction--the net angular momentum of the infalling cloud. This means it flattens out into a disk, known as an accretion disk. That stays in orbit. If there's enough of it, it will form planets (as in the case of our solar system). If there's much more of it, it might even form stars (as in the case of our galaxy). But there's really no easy way to prevent such a disk from forming, and when it forms, it will be highly visible, and it won't be redshifted.
Since the article mentions there is more than one example of this phenomenon, it doesn't sound like a coincidence or a mesurement error.
That has also been said about ESP.
Thanks for the reply. I'm still interested in how, spectroscopically I presume, interactions between the quasar and galaxy are determined that would lead to the suggestion that the quasar and the galaxy are together. Any thoughts?