{"id":277,"date":"2021-01-03T15:14:06","date_gmt":"2021-01-03T06:14:06","guid":{"rendered":"http:\/\/sasakitakanori.com\/en\/?p=277"},"modified":"2021-01-03T16:46:19","modified_gmt":"2021-01-03T07:46:19","slug":"yamashiki-et-al-apj-2019","status":"publish","type":"post","link":"http:\/\/sasakitakanori.com\/en\/archives\/277","title":{"rendered":"Yamashiki et al., ApJ (2019)"},"content":{"rendered":"\n<p>Yosuke A. Yamashiki, Hiroyuki Maehara, Vladimir Airapetian, Yuta Notsu, Tatsuhiko Sato, Shota Notsu, Ryusuke Kuroki, Keiya Murashima, Hiroaki Sato, Kosuke Namekata,&nbsp;<span style=\"text-decoration: underline;\">Takanori Sasaki<\/span>, Thomas B. Scott, Hina Bando,&nbsp;Subaru Nashimoto, Fuka Takagi, Cassandra Ling, Daisaku Nogami &amp;&nbsp;Kazunari Shibata,&nbsp;Impact of Stellar Superflares on Planetary Habitability,&nbsp;<em>The&nbsp;Astrophysical Journal,&nbsp;<\/em><strong>881<\/strong><em>,&nbsp;<\/em>114(24pp) (2019)<\/p>\n\n\n\n<p><strong>Abstract<\/strong><\/p>\n\n\n\n<p>High-energy radiation caused by exoplanetary space weather events from planet-hosting stars can play a crucial role in conditions promoting or destroying habitability in addition to the conventional factors. In this paper, we present the&nbsp;first quantitative impact evaluation system of stellar&nbsp;flares on the habitability factors with an emphasis on the impact of stellar proton events. We derive the maximum&nbsp;flare energy from stellar star spot sizes and examine the impacts of&nbsp;flare-associated ionizing radiation on CO2, H2, and N2+&nbsp;O2-rich atmospheres of a number of well-characterized terrestrial type exoplanets. Our simulations based on the Particle and Heavy Ion Transport code System suggest that the estimated ground-level dose for each planet in the case of terrestrial-level atmospheric pressure&nbsp;(1 bar)&nbsp;for each exoplanet does not exceed the critical dose for complex&nbsp;(multicellular)&nbsp;life to persist, even for the planetary surface of Proxima Centauri b, Ross-128 b, and TRAPPIST-1 e. However, when we take into account the effects of the possible maximum&nbsp;flares from those host stars, the estimated dose reaches fatal levels at the terrestrial lowest atmospheric depth on TRAPPIST-1 e and Ross-128 b. Large&nbsp;fluxes of coronal X-ray and ultraviolet radiation from active stars induce high atmospheric escape rates from close-in exoplanets, suggesting that the atmospheric depth can be substantially smaller than that on Earth. In a scenario with the atmospheric thickness of one-tenth of Earth\u2019s, the radiation dose from close-in planets including Proxima Centauri b and TRAPPIST-1 e reaches near fatal levels with annual frequency of&nbsp;flare occurrence from their host stars.<\/p>\n\n\n\n<p><strong><a href=\"http:\/\/sasakitakanori.com\/wp-content\/uploads\/2019\/08\/yamashiki_apj_2019.pdf\">Read the full article<\/a><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<div class=\"mh-excerpt\"><p>Yosuke A. Yamashiki, Hiroyuki Maeha <a class=\"mh-excerpt-more\" href=\"http:\/\/sasakitakanori.com\/en\/archives\/277\" title=\"Yamashiki et al., ApJ (2019)\">[&#8230;]<\/a><\/p>\n<\/div>","protected":false},"author":2,"featured_media":304,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":{"0":"post-277","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-recent_publications"},"_links":{"self":[{"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/posts\/277","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/comments?post=277"}],"version-history":[{"count":2,"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/posts\/277\/revisions"}],"predecessor-version":[{"id":305,"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/posts\/277\/revisions\/305"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/media\/304"}],"wp:attachment":[{"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/media?parent=277"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/categories?post=277"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/sasakitakanori.com\/en\/wp-json\/wp\/v2\/tags?post=277"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}