{"id":165,"date":"2010-05-25T11:02:50","date_gmt":"2010-05-25T02:02:50","guid":{"rendered":"http:\/\/home.hiroshima-u.ac.jp\/uemuram\/?p=165"},"modified":"2015-08-28T14:58:05","modified_gmt":"2015-08-28T05:58:05","slug":"infraredoptical-x-ray-simultaneous-observations-of-x-ray-flares-in-grb-071112c-and-grb-080506","status":"publish","type":"post","link":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/infraredoptical-x-ray-simultaneous-observations-of-x-ray-flares-in-grb-071112c-and-grb-080506\/","title":{"rendered":"Infrared\/optical &#8211; X-ray simultaneous observations of X-ray flares in GRB 071112C and GRB 080506"},"content":{"rendered":"<p>T. Uehara, M. Uemura, K. S. Kawabata, Y. Fukazawa, R. Yamazaki, &#8220;Infrared\/optical &#8211; X-ray simultaneous observations of X-ray flares in GRB 071112C and GRB 080506&#8221;, A&amp;A, vol. 519, p. 56, 2010.<\/p>\n<p>We investigate the origin of short X-ray flares which are occasionally observed in early stages of afterglows of gamma-ray bursts (GRBs). We observed two Swift events, GRB 071112C and GRB 080506, before the start of X-ray flares in the optical and near-infrared (NIR) bands with the 1.5-m Kanata telescope. In conjunction with published X-ray and optical data, we analyzed densely sampled light curves of the early afterglows and spectral energy distributions (SEDs) in the NIR-X-ray ranges. We found that the SEDs had a break between the optical and X-ray bands in the normal decay phases of both GRBs regardless of the model for the correction of the interstellar extinction in host galaxies of GRBs. In the X-ray flares, X-ray flux increased by 3 and 15 times in the case of GRB 071112C and 080506, respectively, and the X-ray spectra became harder than those in the normal decay phases. No significant variation in the optical-NIR range was detected together with the X-ray flares. These results suggest that the X-ray flares were associated with either late internal shocks or external shocks from two-component jets.<\/p>\n<p><a href=\"http:\/\/home.hiroshima-u.ac.jp\/uemuram\/muhasc-content\/uploads\/2015\/04\/ueh10grb.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-166 size-full\" src=\"http:\/\/home.hiroshima-u.ac.jp\/uemuram\/muhasc-content\/uploads\/2015\/04\/ueh10grb.png\" alt=\"ueh10grb\" width=\"817\" height=\"364\" srcset=\"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-content\/uploads\/2015\/04\/ueh10grb.png 817w, https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-content\/uploads\/2015\/04\/ueh10grb-300x134.png 300w\" sizes=\"auto, (max-width: 817px) 100vw, 817px\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>T. Uehara, M. Uemura, K. S. Kawabata, Y. Fukazawa, R. Yamaza<\/p>\n","protected":false},"author":2,"featured_media":166,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-165","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-grb"],"_links":{"self":[{"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/posts\/165","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/comments?post=165"}],"version-history":[{"count":2,"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/posts\/165\/revisions"}],"predecessor-version":[{"id":309,"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/posts\/165\/revisions\/309"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/media\/166"}],"wp:attachment":[{"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/media?parent=165"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/categories?post=165"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/home.hiroshima-u.ac.jp\/uemuram\/wp-json\/wp\/v2\/tags?post=165"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}