{"id":307,"date":"2020-10-26T16:40:15","date_gmt":"2020-10-26T16:40:15","guid":{"rendered":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/?p=307"},"modified":"2025-02-26T13:37:30","modified_gmt":"2025-02-26T13:37:30","slug":"astroseminar-disc-eccentricity-driving-type-i-and-type-ii-outbursts-in-be-x-ray-binaries","status":"publish","type":"post","link":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/2020\/10\/26\/astroseminar-disc-eccentricity-driving-type-i-and-type-ii-outbursts-in-be-x-ray-binaries\/","title":{"rendered":"AstroSeminar: Disc eccentricity driving type I and type II outbursts in Be\/X-ray binaries"},"content":{"rendered":"\n<p><br><strong>This week (28th Oct) the virtual Wednesday talk will be delivered by Dr. Alessia Franchini&nbsp;(Universit\u00e0 Milano-Bicocca), who will present&nbsp;&#8220;Disc eccentricity driving type I and type II outbursts in Be\/X-ray binaries&#8221;. Members of the School can access this seminar via <a href=\"https:\/\/teams.microsoft.com\/l\/meetup-join\/19%3ameeting_ZGQ4OGQwNWUtYmNlNi00M2NhLTgyY2EtMGJlYjBjZjcxMTlh%40thread.v2\/0?context=%7b%22Tid%22%3a%22aebecd6a-31d4-4b01-95ce-8274afe853d9%22%2c%22Oid%22%3a%228e0b96fb-5fc2-4d1a-8df5-d303240e8c57%22%7d\">Microsoft Teams<\/a>&nbsp;<\/strong><br><br><\/p>\n\n\n\n<p>Title : Disc eccentricity driving type I and type II outbursts in Be\/X-ray binaries.&nbsp;<br><br>Abstract: The majority of Be star X-ray binaries are transient systems and show two types of outbursts. Type I outbursts occur on the orbital period while type II or giant outbursts have a duration that is not related to any periodicity of the system.Type I outbursts can be explained with either the binary eccentricity or the presence of the 3:1 Lindblad resonance within a coplanar Be star disc while type II have been suggested to be triggered through Kozai-Lidov oscillations of a strongly misaligned decretion disc.<br>A sufficiently misaligned Be star decretion disc undergoes secular Kozai-Lidov oscillations of eccentricity and inclination and is able to Roche lobe overflow transferring mass over a longer timescale onto the companion neutron star.<br>I am going to give a general introduction on these fascinating systems and their&nbsp;properties. I will then present the results of new numerical hydrodynamical simulations that&nbsp;explore the dynamics of the Be star accretion disc and in particular aim at explaining the types of outbursts with the development of the disc eccentricity. I will discuss the dynamics of an initially highly inclined disc around the neutron star, formed as a consequence of Kozai-Lidov oscillations of the Be star disc and its effect on the neutron star accretion rate.&nbsp;<br><br>The seminar programme can be found at: &nbsp;<a href=\"https:\/\/www2.le.ac.uk\/departments\/physics\/research\/theoretical_astro\/seminar-program\/seminars\">https:\/\/www2.le.ac.uk\/departments\/physics\/research\/theoretical_astro\/seminar-program\/seminars<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This week (28th Oct) the virtual Wednesday talk will be delivered by Dr. Alessia Franchini&nbsp;(Universit\u00e0 Milano-Bicocca), who will present&nbsp;&#8220;Disc eccentricity driving type I and type II outbursts in Be\/X-ray binaries&#8221;. Members of the School can access this seminar via Microsoft Teams&nbsp; Title : Disc eccentricity driving type I and type II outbursts in Be\/X-ray binaries.&nbsp; [&hellip;]<\/p>\n","protected":false},"author":315,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[],"class_list":["post-307","post","type-post","status-publish","format-standard","hentry","category-seminar"],"_links":{"self":[{"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/posts\/307","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/users\/315"}],"replies":[{"embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/comments?post=307"}],"version-history":[{"count":6,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/posts\/307\/revisions"}],"predecessor-version":[{"id":397,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/posts\/307\/revisions\/397"}],"wp:attachment":[{"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/media?parent=307"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/categories?post=307"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/tags?post=307"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}