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Reading my first Astrophys paper

  1. May 28, 2008 #1
    I'm getting a little stuck on terminology, but most of it can be looked up in wikipedia. However, there's one term I'm having trouble with.

    The paper is for a model of micrometeorites entering the atmosphere. It says:

    "Entry velocities ranged between 11.2 and 72 km/sec following a v^-5,394 velocity distribution,"

    What is a "a v^-5,394 velocity distribution" ?
  2. jcsd
  3. May 28, 2008 #2
    That just means that the distribution of micrometeorite velocities between 11.2 and 72 km/s looks like the plot of v^{-5394}.

    i.e. - it falls off really steeply as velocity increases.
  4. May 28, 2008 #3
    Okay, that makes sense. Any idea how I could convince MatLab to make such a matrix for me :)
  5. May 29, 2008 #4
    Ah, what they're describing in the paper isn't a matrix, it's best viewed as a probability density function.

    If you wanted to display it as a probability distribution, you would just plot v^{-5394}, but would need to multiply it by a normalization constant. That constant (using latex formating) will be 1 / (\int_11.2^72 v^{-5394}). That is to say, 1 over the integral of v^{-5394} from 11.2 km/s to 72 km/s.

    Do you need a matrix for some other reason?
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