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Please Help. Radio Spectroscopy -> Finding the doppler shift in a graph

  1. Mar 13, 2008 #1
    I've been trying this for 3 hours and I'm getting nowhere. These are the graphs I made for Hydrogen Intensity vs Frequency for a radio telescope that transits the sun and galactic arms of the galaxy.

    http://img220.imageshack.us/img220/5904/helpgraphia6.jpg [Broken]

    http://img139.imageshack.us/img139/8038/graph1nr8.jpg [Broken]

    http://img139.imageshack.us/img139/4486/graph2pp2.jpg [Broken]

    I need to find the rotation speed of the earth and the galactic arms. So I know I need to measure the doppler shift ...but my problem is, I don't know which spikes correspond to what. What spikes are from the sun or local space and which are from the galactic arms.

    Anybody please help?
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Mar 14, 2008 #2

    Nevermind this I figured most of it out ---

    but can someone please help me determine which spike comes from the sun?

    I know it's either the really thin intense one that's on all 3 ...but that looks more like a stray point to me ....or it's the other really large one that's thicker
    Last edited by a moderator: May 3, 2017
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