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Star clustering (Help me )

  1. Jun 6, 2009 #1
    Star clustering.... (Help me....)

    Here goes....:cry:

    I am currently taking a BS Degree in Applied Physics and I do need someone's help right now. My research is all about the clustering of stars... Frankly speaking, I don't know where to start. I just first want to organize my thoughts and step by step answer the problems that are bugging me....

    First, I want to know what are the values I need to look for. This research started when I was reading a journal about the clustering of the galaxies. I just narrowed the research and reduced it to star clustering. I've read that the galaxy clustering started with the presence of the black hole. So I'm assuming that one of the components I'm gonna need is the gravitational pull produced by a black hole. I don't know what's next.

    Second, I need to know what mathematical approaches I'm gonna use to estimate the star clustering. I am also gonna need some data regarding this research... All I can assume is that I can only get it from NASA... But I don't know how to contact them or if they will provide data (I am kind of assuming that it is somehow confidential... I really don't know...)...

    In the end of the research I'm gonna have to simulate the clustering in such a way that given a certain initial conditions, the program shall be able to estimate how a certain group of stars will cluster....

    To tell you honestly.... Our university doesn't quite offer much knowledge regarding this field... Therefore, I'm gonna need all the help I could get.... I also don't have much resources like journals, books, and contacts (connections) that can get me through this research.... I'm planning to make this as my thesis..... Please help me.... This is the only topic that I had since I really don't have journals and stuff....

    I'm gonna need your comments, suggestions, reactions, etc....

    I also need your opinion regarding if I have to give up on this topic or pursue it... I'm really confused right now.... So please help me...:cry::cry::cry:
  2. jcsd
  3. Jun 6, 2009 #2


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    Re: Star clustering.... (Help me....)

    there are different theories about the origin of clumping of matter into stars, star clusters, galaxies, galaxy clusters.

    I personally do not think that we have a final answer yet. But there are some very good models. I personally think that the best you can do is to describe one model. You do not describe the truth, but you can discuss what some people think happens.

    I personally am familiar with only one model of socalled "structure formation" which depends not on black holes but on dark matter.

    According to this model, the early universe was almost uniform density, with only very slight random fluctuations.

    In the early universe the dark matter (which really should be called "transparent matter" because we cannot see it) was about 5 times more abundant than the ordinary baryonic matter (the atoms we are familiar with).

    The dark matter was cold and slow-moving because it does not interact with light. But the baryonic matter was very hot and fast moving because it absorbs and radiates light. So the terrible light of the early universe excited the baryonic matter to move around very fast.

    So it was the constructive effect of the cold slow-moving dark matter which first began the work of clumping and condensing into structures. Wherever a random wave caused a small increase in density, then that extra density gravity would draw more in towards it and increase the density still more.

    For things to condense and gather, by gravity, there must be a way to drain off excess energy, and this was provided by expansion. Expansion actually slows stuff and causes cooling of hot stuff, but this is a rather subtle point. Too rapid expansion can prevent condensation. But the right amount can help.

    So the dark matter first collected into clouds, and then these clouds gravity attracted the ordinary matter and gather it together.

    And so we see to this day, because each galaxy is surrounded by a cloud of dark matter which helped that galaxy gather together. by making a region of extra gravity.

    But the dark matter does not continue condensing because it doesn't "stick together". It cannot radiate off extra energy in the form of light and heat. So it can help in the initial stage of gathering matter, while the universe is expanding fairly rapidly, but afterwards it stops and remains in a dispersed form.

    Now this is a complicated story. It may not be the story you want to tell in your paper. But in case you want to find out more about this particular model of structure formation, there are some video lectures by Nobel laureate George Smoot that are very good.

    Google "Smoot TED" There is a club called TED that invited Smoot to give them a slide show.

    Also there is a video of the one hour talk by Smoot, paid for by the Honeywell company, gave it to the Pune India university students. Very good slide show. But only parts have to do with structure formation. Here are links to it:
    Nobelist George Smoot talking about the CMB and what things it tells us.
    Very skillful presentation with animated graphs, shows what bumps in the power spectrum mean, and why. Part of the "Honeywell Nobel" lecture series.










    Also google "Wiki structure formation" and see what Wikipedia says about the universe's structure formation.

    However, to my personal taste the best is what you get when you google "Smoot TED" because he shows computer animation movies of how the dark matter collects into what eventually becomes a kind of skeleton of the structure of the universe. Cobweb wisps, and where the wisps and strands cross the galaxy clusters form, and so a computer simulation of dark matter being gathered by gravity produces, finally, a pattern of structure (with wisps and strands and clumps and voids) similar to what we actually see.
    Last edited by a moderator: Apr 24, 2017
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