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    • Fulltext

       

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      Permanent link:
      https://www.ias.ac.in/article/fulltext/joaa/001/01/0047-0066

    • Keywords

       

      21 cm absorption; shocked clouds; spin temperature; high velocities

    • Abstract

       

      A 21 cm absorption measurement over a long path length free of the effects of differential galactic rotation indicates the existence of two distinct cloud populations in the plane. One of them consisting of cold, dense clouds has been well studied before. The newly found hot clouds appear to be at least five times more numerous. They have a spin temperature of ~ 300 K, an rms velocity of ~ 35 km s-1, twice the total mass, and hundred times the kinetic energy of the cold clouds. Over long path lengths, the hot clouds haveNH/kpc ~ 2 X 1021 cm-2 Kpc-1, and are estimated to have individual column densities ≤ 1020 cm-2. We propose that they are shocked clouds found only within supernova bubbles and that the cold clouds are found in the regions in-between old remnants, immersed in an intercloud medium. We conclude that the solar neighbourhood must be located between old supernova remnants rather than within one.

    • Author Affiliations

       

      V. Radhakrishnan1 G. Srinivasan1

      1. Raman Research institute, Bangalore - 560080

    • Dates

       
      Published
      September 1980
      Manuscript received
      14 April 1980
      Accepted
      29 May 1980

  • Journal of Astrophysics and Astronomy | News

    • Continuous Article Publication

      Posted on January 27, 2016

      Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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