{"id":129213,"date":"2021-10-19T17:22:51","date_gmt":"2021-10-20T00:22:51","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2021\/10\/pdf-low-efficiency-long-gamma-ray-bursts-a-case-study-with-at2020blt"},"modified":"2021-10-19T17:22:51","modified_gmt":"2021-10-20T00:22:51","slug":"pdf-low-efficiency-long-gamma-ray-bursts-a-case-study-with-at2020blt","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2021\/10\/pdf-low-efficiency-long-gamma-ray-bursts-a-case-study-with-at2020blt","title":{"rendered":"(PDF) Low-efficiency long gamma-ray bursts: A case study with AT2020blt"},"content":{"rendered":"<p><a class=\"aligncenter blog-photo\" href=\"https:\/\/lifeboat.com\/blog.images\/pdf-low-efficiency-long-gamma-ray-bursts-a-case-study-with-at2020blt2.jpg\"><\/a><\/p>\n<p>The Zwicky Transient Facility recently announced the detection of an optical transient AT2020blt at redshift $z=2.9$, consistent with the afterglow of a gamma-ray burst. No prompt emission was observed. We analyse AT2020blt with detailed models, showing the data are best explained as the afterglow of an on-axis long gamma-ray burst, ruling out other hypotheses such as a cocoon and a low-Lorentz factor jet. We search \\textit{Fermi} data for prompt emission, setting deeper upper limits on the prompt emission than in the original detection paper. Together with \\konus{} observations, we show that the gamma-ray efficiency of AT2020blt is $\\lesssim 2.8\\%$, lower than $98.4\\%$ of observed gamma-ray bursts. We speculate that AT2020blt and AT2021any belong to the low-efficiency tail of long gamma-ray burst distributions that are beginning to be readily observed due to the capabilities of new observatories like the Zwicky Transient Facility.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The Zwicky Transient Facility recently announced the detection of an optical transient AT2020blt at redshift $z=2.9$, consistent with the afterglow of a gamma-ray burst. No prompt emission was observed. We analyse AT2020blt with detailed models, showing the data are best explained as the afterglow of an on-axis long gamma-ray burst, ruling out other hypotheses such [\u2026]<\/p>\n","protected":false},"author":427,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[],"class_list":["post-129213","post","type-post","status-publish","format-standard","hentry","category-futurism"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/129213","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/427"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=129213"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/129213\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=129213"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=129213"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=129213"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}