Talk:Intracluster medium

Wiki Education Foundation-supported course assignment
This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Drbingbing. Peer reviewers: WhiskeyJack27.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 00:44, 17 January 2022 (UTC)

Untitled Thread
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)

Why I PRODed It
It states an absurdity and the 1 source given provides no support for same. Possible purposeful hoax/attempt to discredit wiki. Lycurgus (talk) 05:28, 28 December 2008 (UTC)


 * Suppose it may not be malicious but if there is no proof/evidence, say comparable to that that is taken as substantiating extrasolar planets and black holes, then at a very minimum the matter must be presented as a hypothesis. Even then it must be stated as such in a primary source. Instead it is presented as a known fact of nature without any substantiation. 72.228.150.44 (talk) 05:34, 28 December 2008 (UTC)


 * Also looked at the "Theoretical Progress" section of the reference the editor was told to "sink his teeth into" after which he sheepishly turned tail, and nowhere did I see what is stated in detail in current body of the article stated there as, as I say, as a known fact of nature (or for that matter one inferable in the way the aforementioned phenomena are). Why was that not given as a source for the article if it is in fact substantive proof of what it asserts as known fact? 72.228.150.44 (talk) 08:15, 28 December 2008 (UTC)


 * And finally, black holes, are mere virtual certainties, not known facts as no probes nor communications with first hand witnesses of such phenomena have yet occurred. The optical evidence of the extrasolar planets is perhaps close enough to it perhaps not (it is for me might reasonably not be for some others awaiting direct observations). 72.228.150.44 (talk) 08:29, 28 December 2008 (UTC)


 * I'm probably ready to retract much/most/all of the above except for the essential matter: the distinction between known fact and scientific/likely conjecture. 71.186.172.73 (talk) 20:33, 1 January 2009 (UTC)


 * Finally, I suppose this is purposeless as it would already be an advance to have science taken at its (philosophically weak) word and asking for the distinction above to be recognized is asking too much. 72.228.150.44 (talk) 09:27, 2 January 2009 (UTC)

Dark Matter
The line: "However, most of the mass in a galaxy cluster consists of dark matter." is written as if dark matter is a proven fact. It is not, it is just a theory. Maybe change it to: "..may consists of dark matter." ? — Preceding unsigned comment added by Gerard.van.Dorst (talk • contribs) 07:56, 21 June 2015 (UTC)

What data

 * Could we add eg notable clusters that have had the ICM (spectra, density, and temp) measured ? Is any detected in the local group ?
 * How do the characteristics of the ICM vary with size, density and nature of the galactic clusters ? - Rod57 (talk) 02:26, 14 January 2017 (UTC)

Wikiedu Changes
I was assigned this article for a wiki edu project. I have reworded most of the article for clarity and flow, added citations to important information, and updated a section with more current information. The Heating section could still use some work as I ran out of time and in my opinion the cooling flows section could be a little more fleshed out with properties of the flow including models of the inhomogeneities, multi-phase gas models, and entropy models. I also would like to include a bit more about the heating mechanisms as the section is very brief and not particularly enlightening. Drbingbing (talk) 21:45, 19 March 2017 (UTC)

Updated Page
I went ahead and removed the "Shockingly unsubstantiated material" after backing up some claims and reworking others. I'll be keeping an eye on this page and updating as semi-regularly as new Chandra studies are done. Drbingbing (talk) 18:29, 11 January 2019 (UTC)

A Commons file used on this page has been nominated for deletion
The following Wikimedia Commons file used on this page has been nominated for deletion: Participate in the deletion discussion at the nomination page. —Community Tech bot (talk) 01:59, 9 January 2020 (UTC)
 * A2199 Xray Optical.jpg

Warm-hot intergalactic medium
How does Warm–hot intergalactic medium relate? Subset? Disjoint? Competing concept? --JWB (talk) 16:59, 24 June 2020 (UTC)