Rotating Galaxy Clusters?

[Fisica]

Are the rotation curves for the galaxies different for the galaxies near the centers of the cluster compared to the galaxies farther from the cluster center?

 

Are there measurements that give the rotation curves for galaxy clusters?

 

Since the effect of Compton scattering is so tiny, do we currently have the sensitivity and resolution at these low frequencies for the SZ effect to give accurate measurements of the clusters? Can the SZ effect determine a rotation curve for the galaxy clusters?

 

What does the information that we have now from star, galaxy, and black hole formation tell us about the cluster structure and evolution of the clusters? What physical mechanisms affect the structure and dynamics of galaxy clusters?

 

Does anyone have any links to (free full text) peer reviewed articles?

 

Thanks!

[Mchurd]

I smell college research project question...

[Fisica]

I smell college research project question...

 

You must have allergies. It’s 100% pure curiosity.

[Airbrush]

Your questions are way beyond me, but here is what I think galaxy clusters are doing.

 

They orbit their combined center of mass is a disorderly manner compared to the planets of our solar system orbiting the sun, or our solar system orbiting the Milky Way. The galaxies in a cluster are orbiting each other every which way, not neatly on the same plane. They also collide and tear each other apart. They even tear each other apart without colliding, just by passing each other too close. Anyone please correct me if I am wrong here.

[Martin]

Are the rotation curves for the galaxies different for the galaxies near the centers of the cluster compared to the galaxies farther from the cluster center?

 

Are there measurements that give the rotation curves for galaxy clusters?

 

Since the effect of Compton scattering is so tiny, do we currently have the sensitivity and resolution at these low frequencies for the SZ effect to give accurate measurements of the clusters? Can the SZ effect determine a rotation curve for the galaxy clusters?

 

What does the information that we have now from star, galaxy, and black hole formation tell us about the cluster structure and evolution of the clusters? What physical mechanisms affect the structure and dynamics of galaxy clusters?

 

Does anyone have any links to (free full text) peer reviewed articles?

 

Thanks!

 

Those are nice questions. I can't answer without doing some hunting. For now I will just tell you my superficial reaction which can easily be wrong.

 

I know that DM density maps are made using weak gravitational lensing. They look like topographical maps of hilly terrain. The DM is mapped for galaxy clusters. The DM makes up most of the mass of the clusters.

 

I have not heard of clusters of galaxies ROTATING. I thought that the galaxies in the cluster just have some random velocities, like stars in a star-cluster. Or like gnats in a cloud of gnats.

I didn't hear about any organized pattern.

 

But one can tell at least the radial component of these random velocities, of the galaxies in a cluster. For the cluster to be stable and not fly apart, these random velocities must be less than the escape velocity. So one can check that against what is estimated about the mass, including the large DM component.

 

I hope someone else will find an example of one of those DM density maps superimposed on a visible cluster of galaxies. Weak lensing is a great way of mapping DM concentration!

Maybe also someone else knows more certain details and can fill in. I have to go out immediately. But liked the questions and wanted to reply right away. Hello Fisica and welcome.

Edited July 17, 2010 by Martin

[Fisica]

Hi Martin,

 

Thank you for your reply. I did a little searching and found a couple of links on my own. I have more if you'd like and a few on the Sunyaev-Zeldovich effect. Is there any chance that you would give me a quick rundown on this forum? How are disruptive members handled? Are there a lot of cranks and how are they dealt with? I hope you don’t mind me asking but what do you think the average ages of the members are? Are there any that have PhDs?

 

Thanks!

 

Fisica

 

The Astrophysical Journal

Kinetic Sunyaev-Zeldovich effect from galaxy cluster rotation

[Royston]

Are the rotation curves for the galaxies different for the galaxies near the centers of the cluster compared to the galaxies farther from the cluster center?

 

Are there measurements that give the rotation curves for galaxy clusters?

 

Since the effect of Compton scattering is so tiny, do we currently have the sensitivity and resolution at these low frequencies for the SZ effect to give accurate measurements of the clusters? Can the SZ effect determine a rotation curve for the galaxy clusters?

 

What does the information that we have now from star, galaxy, and black hole formation tell us about the cluster structure and evolution of the clusters? What physical mechanisms affect the structure and dynamics of galaxy clusters?

 

Does anyone have any links to (free full text) peer reviewed articles?

 

Thanks!

 

First, there are two types of SZ effect, thermal is used for distance measurements whereas kinetic deals with bulk motion relative to the cosmic rest frame, so the latter, despite being weak, would give some information on rotation. Cluster rotation is very complicated, although they do rotate (to an extent.) There is generally an accretor, where we're concerned this is M31, however the Milky Way also acts as an accretor. There are star trails where our most closest galactic neighbours are spiralling in towards the Milky Way, and we in turn, are spiraling towards M31 (I'm using the term spiraling loosely BTW, huge distances and timescales et.c). The SZ effect will be used in the next gen of CMB maps, so it's early days.

 

As for clumping and cluster structure, the general clumping of DM (in the early Universe) is outweighed by young galaxies and their DM halos (see Quasar distribution), I guess that stands to reason where gravity is involved, but I may be missing something. I realize this is a late reply, but I covered the SZ effect recently, so thought I'd add my, albeit, basic knowledge on the subject.

Edited July 30, 2010 by Royston