Talk:Intracluster medium
From Wikipedia, the free encyclopedia
 |
This article is within the scope of WikiProject Physics, which collaborates on articles related to physics. |
| ??? | This article has not yet received a rating on the assessment scale. [FAQ] |
| ??? | This article has not yet received an importance rating within physics. |
|
Help with this template Please rate this article, and then leave comments to explain the ratings and/or to identify its strengths and weaknesses. |
|
I created this page today; it's a pretty bare-bones overview, but I'd love to see somebody give a little history or examples of relevance. Perhaps when I have more time I can add some of that myself! Motorneuron 17:16, 27 February 2006 (UTC)motorneuron
You say most of the matter is baryons, I thought most of the gravitational matter in a cluster was dark matter. I had learned that the x-ray emitting baryons in the cluster gas were useful because they traced out the gravitational potential created mostly by the dark matter. Maybe you want to look into that further.
You're right that most of the matter in a cluster is dark matter, but the ICM is defined as just being the gas at the center of the cluster. So by definition, we're only looking at the baryons when we talk about the ICM. But the cluster's dark matter still does compose the bulk of its mass. Motorneuron 16:49, 17 July 2006 (UTC)motorneuron
I am not an expert on this subject, but I know enough about physics and astronomy to know that there are many substantive and factual errors in this entry. No references are cited, much of the basic terminology is used incorrectly, and some of the material sounds, frankly, made up. I will recommend this article for deletion or delete it myself unless improvements/citations are made. Wikipedia is not an area to promote your own research, untested (or not thouroughly tested) theories, or personnal ideas or beliefs. MPA —Preceding unsigned comment added by 140.32.122.60 (talk) 22:25, 27 December 2007 (UTC)
I agree the article could do with some references. Except for the intracluster dust section, which does seem to be overly long and promotes particular recent research, what bits do you think are wrong or made up? I work in this area of research (no references to me in the article!) - I think most of the material is okay - although it could do with wording better. Which of the terminology is incorrect? Xioxox (talk) 19:37, 1 January 2008 (UTC)
Galaxy clusters are merely collections of galaxies held together by mutual gravitational attraction (I know dark matter is involved as well, but that doesn't speak to this discussion). They do not have clearly defined "centers." Volume-wise or center-of-gravity-wise, the central point of most clusters is simply a point in (virtually) empty intergalactic space. What is the difference between the intergalactic and intracluster medium? As far as I'm aware, there is none. While some galaxy clusters may, by happenstance, have a large central galaxy near where their supposed "centers" appear to be, this is only by coincidence. This is the case with Abell 2199. The picture of Abell 2199 used at the beginning of the article is misleading and should not be used because it is not even a picture of Abell 2199 in its entirety, but of only a single galaxy (I assume the large galaxy that happens to lie near its "center," but even this is not clear). It is clear the picture is of only a single galaxy from the distance scale on the right side of the picture labeled "50 thousand light years." This is the scale of galaxies, not galaxy clusters, which are on the scale of megaparsecs. The caption of that picture is incorrect as it is describing the interstellar medium of that particular galaxy, not of galaxy cluster Abell 2199. There are certainly X-Ray sources within galaxies and from active galaxies, but not from the material between galaxies (as far as I'm aware, though I know stars do occasionally get ejected from galaxies). Anyway, I've gone on enough. Most of the rest of the assertions in this article sound similarly suspect. But, like I said, I am no expert. Prove me wrong with some sort of evidence or delete this article. MPA —Preceding unsigned comment added by 140.32.122.60 (talk) 20:16, 18 March 2008 (UTC)
Nonsense. I work professionally on studying galaxy clusters - they contain a hot plasma (millions of degrees, density of 10**-2 to 10**-4 cm**-3). This is seen in X-rays. What do you think the X-ray picture of Abell 2199 is? That X-ray image is concentrating on the inner core of the galaxy cluster. The X-ray emission extends for mega parsecs. Why not take a look at a general article on galaxy clusters if you think you are correct? Here's an old but fairly easy to understand review for you to get your teeth into http://nedwww.ipac.caltech.edu/level5/March02/Sarazin/Sarazin_contents.html Xioxox (talk) 19:54, 19 April 2008 (UTC)
D'oh! You are correct. I am plain, old wrong - and feel a little silly. I'll leave my comments above as a lesson for others to make sure they check and re-check their assertions. —Preceding unsigned comment added by 140.32.122.60 (talk) 22:34, 25 April 2008 (UTC)
