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Homework Help: Initial mass function problem

  1. Oct 16, 2009 #1
    1. The problem statement, all variables and given/known data
    Hello! I am currently working on a initial mass problem and getting nowhere, I need a little help here, the question states

    consider a newly formed globular cluster, with total mass 10e6 times that of the sun, and an initial mass function dN/dm = a.m(-2.35) (-2.35 being the power of m of course) in the mass range 0.1-20 mass of the sun, where m=M/mass of the sun. find a.

    2. Relevant equations

    3. The attempt at a solution
    what i did till now is
    we know that globular clusters have 10e4 to 10e6 stars so

    integral of N(m)dm = 10e6 where m ranges from .1 to 20 mass of the sun
    with this equation I got the value of N which was too small and used the given equation dN/dm = a.m(-2.35) to find a. Is this method correct ?
  2. jcsd
  3. Oct 16, 2009 #2


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    Homework Helper
    Gold Member

    Shouldn't the number of stars in a given mass range [itex]m_1\leq m\leq m_2[/itex] be equal to

    [tex]N=\int_{m_1}^{m_2} dN=\int_{m_1}^{m_2} \frac{dN}{dm}dm[/tex]

  4. Oct 16, 2009 #3
    thank you, ill try using this now
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