{"id":30747,"date":"2010-11-13T16:19:18","date_gmt":"2010-11-13T16:19:18","guid":{"rendered":"http:\/\/euvolution.com\/futurist-transhuman-news-blog\/mapping-the-dark-matter-cosmic-variance\/"},"modified":"2010-11-13T16:19:18","modified_gmt":"2010-11-13T16:19:18","slug":"mapping-the-dark-matter-cosmic-variance","status":"publish","type":"post","link":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/astronomy\/mapping-the-dark-matter-cosmic-variance.php","title":{"rendered":"Mapping the Dark Matter | Cosmic Variance"},"content":{"rendered":"<p>Have any friends or colleagues who don&rsquo;t believe in dark matter? Showing them this should help.<\/p><p><a rel=\"nofollow\" target=\"_blank\" href=\"http:\/\/hubblesite.org\/newscenter\/archive\/releases\/2010\/37\/full\/\"><img loading=\"lazy\" decoding=\"async\" style=\"padding-left:10px; padding-right: 10px;\" src=\"http:\/\/euvolution.com\/futurist-transhuman-news-blog\/wp-content\/plugins\/wp-o-matic\/cache\/0c0b2_hubble-dark-matter-map.jpg\" alt=\"Dark Matter in Abell 1689\" width=\"600\" height=\"615\" class=\"aligncenter size-full wp-image-5757\"><\/a><\/p><p>That ghostly haze is dark matter &mdash; or at least, an impression of the gravitational field created by the dark matter. This is galaxy cluster Abell 1689, in the constellation Virgo. (We feel compelled to add that information, in case you&rsquo;re going to go looking for it in the night sky tonight or something.) It&rsquo;s easy to see that the images of many of the galaxies have been noticeably warped by passing through the gravitational field of the cluster, a phenomenon known as strong gravitational lensing. This cluster has been studied <a rel=\"nofollow\" target=\"_blank\" href=\"http:\/\/apod.nasa.gov\/apod\/ap030109.html\">for a while<\/a> using strong lensing. The idea is that the detailed distribution of dark matter affects the specific ways in which different background images are distorted (similar to what was used to analyze the <a rel=\"nofollow\" target=\"_blank\" href=\"http:\/\/blogs.discovermagazine.com\/cosmicvariance\/2006\/08\/21\/dark-matter-exists\/\">Bullet Cluster<\/a>). Astronomers use up massive amounts of computer time constructing different models and determining where the dark matter has to be to distort the galaxies in just the right way. Now Dan Coe and collaborators have made <a rel=\"nofollow\" target=\"_blank\" href=\"http:\/\/hubblesite.org\/newscenter\/archive\/releases\/2010\/37\/full\/\">an unprecedentedly high-precision map<\/a> of where the dark matter is (paper <a rel=\"nofollow\" target=\"_blank\" href=\"http:\/\/adsabs.harvard.edu\/abs\/2010ApJ...723.1678C\">here<\/a>). <\/p><p>This isn&rsquo;t all about the pretty pictures. We have theoretical predictions about how dark matter should act, and it&rsquo;s good to compare them to data. Interestingly, the fit to our favorite models is not perfect; this cluster, and a few others like it, are more dense in a central core region than simple theories predict. This is an opportunity to learn something &mdash; perhaps clusters started to form earlier in the history of the universe than we thought, or perhaps there&rsquo;s something new in the <a rel=\"nofollow\" target=\"_blank\" href=\"http:\/\/blogs.discovermagazine.com\/cosmicvariance\/2010\/10\/29\/dark-worlds\/\">physics of dark matter<\/a> that we have to start taking into account.<\/p><p>But the pretty pictures are certainly a reward in their own right.<\/p><p><a rel=\"nofollow\" target=\"_blank\" href=\"http:\/\/feedads.g.doubleclick.net\/~a\/W0XeCO5YTNn9H8TqIpcIB3XLtD4\/0\/da\"><img decoding=\"async\" src=\"http:\/\/euvolution.com\/futurist-transhuman-news-blog\/wp-content\/plugins\/wp-o-matic\/cache\/0c0b2_di\" border=\"0\" style=\"padding-left:10px; padding-right: 10px;\"><\/a><br><a rel=\"nofollow\" target=\"_blank\" href=\"http:\/\/feedads.g.doubleclick.net\/~a\/W0XeCO5YTNn9H8TqIpcIB3XLtD4\/1\/da\"><img decoding=\"async\" src=\"http:\/\/euvolution.com\/futurist-transhuman-news-blog\/wp-content\/plugins\/wp-o-matic\/cache\/0c0b2_di\" border=\"0\" style=\"padding-left:10px; padding-right: 10px;\"><\/a><\/p><p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/euvolution.com\/futurist-transhuman-news-blog\/wp-content\/plugins\/wp-o-matic\/cache\/0c0b2_9mSGO_a98ew\" height=\"1\" width=\"1\" style=\"padding-left:10px; padding-right: 10px;\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/euvolution.com\/futurist-transhuman-news-blog\/wp-content\/plugins\/wp-o-matic\/cache\/0c0b2_2QObaPbncgA\" height=\"1\" width=\"1\" style=\"padding-left:10px; padding-right: 10px;\"><\/p>","protected":false},"excerpt":{"rendered":"<p>Have any friends or colleagues who don&rsquo;t believe in dark matter? Showing them this should help.That ghostly haze is dark matter &mdash; or at least, an impression of the gravitational field created by the dark matter. This is galaxy cluster &hellip; <a href=\"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/astronomy\/mapping-the-dark-matter-cosmic-variance.php\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"limit_modified_date":"","last_modified_date":"","_lmt_disableupdate":"","_lmt_disable":"","footnotes":""},"categories":[21],"tags":[],"class_list":["post-30747","post","type-post","status-publish","format-standard","hentry","category-astronomy"],"modified_by":null,"_links":{"self":[{"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/posts\/30747"}],"collection":[{"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/comments?post=30747"}],"version-history":[{"count":0,"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/posts\/30747\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/media?parent=30747"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/categories?post=30747"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/tags?post=30747"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}