Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Is there also a He 'fog'?

  1. Feb 14, 2006 #1


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Blue-ward of the Lyman limit, the sky is pretty much opaque, beyond a few pc (except in one or two directions, such as the Lockman hole), until well into the soft X-ray region, due to absorption by neutral H.

    H is a ubiquitous component of the ISM (and IGM). So is He.

    Are there two regions of the EM spectrum with similar 'fogs'? One corresponding to absorption by neutral He, the other by He+?

    I did a quick google search, but didn't turn up anything in the way of papers reporting good observations.
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you help with the solution or looking for help too?
Draft saved Draft deleted

Similar Discussions: Is there also a He 'fog'?
  1. What did he mean? (Replies: 0)

  2. He-4 abundance (Replies: 2)

  3. He II, O III lines? (Replies: 2)