Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Timeline of knowledge about the interstellar and intergalactic medium
open-in-new
<h2 id="references">References</h2> <ol> <li id="fn:1"><p>Kanipe, Jeff (2011-01-27). The Cosmic Connection: How Astronomical Events Impact Life on Earth. Prometheus Books. ISBN 9781591028826. <a href="9781591028826" target="_blank">9781591028826</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>"V. M. Slipher Papers, 1899-1965". www.azarchivesonline.org. Retrieved 2019-11-29. <a href="http://www.azarchivesonline.org/xtf/view?docId=ead/lowell/VMSlipher.xml" target="_blank">http://www.azarchivesonline.org/xtf/view?docId=ead/lowell/VMSlipher.xml</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>"V. M. Slipher Papers, 1899-1965". www.azarchivesonline.org. Retrieved 2019-11-29. <a href="http://www.azarchivesonline.org/xtf/view?docId=ead/lowell/VMSlipher.xml" target="_blank">http://www.azarchivesonline.org/xtf/view?docId=ead/lowell/VMSlipher.xml</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Ewen, H. I.; Purcell, E. M. (September 1951), "Observation of a Line in the Galactic Radio Spectrum: Radiation from Galactic Hydrogen at 1,420 Mc./sec.", Nature, 168 (4270): 356, Bibcode:1951Natur.168..356E, doi:10.1038/168356a0, S2CID 27595927 <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Gunn, James E.; Peterson, Bruce A. (November 1965), "On the Density of Neutral Hydrogen in Intergalactic Space", Astrophysical Journal, 142: 1633–1641, Bibcode:1965ApJ...142.1633G, doi:10.1086/148444 <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Wilson, R. W.; Jefferts, K. B.; Penzias, A. A. (July 1970), "Carbon Monoxide in the Orion Nebula", Astrophysical Journal, 161: L43, Bibcode:1970ApJ...161L..43W, doi:10.1086/180567 <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> </ol>