{"681396":{"#nid":"681396","#data":{"type":"event","title":"School of Physics CRA Seminar - Dr. Lizhong Zhang","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ESpeaker:\u0026nbsp;\u003C\/strong\u003E Lizhong Zhang\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EHost: \u0026nbsp;\u003C\/strong\u003EJulia Speicher\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ETitle: \u003C\/strong\u003EUnderstanding the dynamics of accretion onto black holes in radiation GRMHD simulations\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbstract:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ERadiation and magnetic fields\u0026nbsp;play crucial roles in shaping the physics of black hole accretion, especially in near- and super-Eddington regimes. To model this process, we solve the GRMHD equations coupled with angle-dependent radiation transfer, which enables us to capture the complex dynamics driven by radiation and magnetic fields in extreme environments. In the super-Eddington regime, the accretion disk thermally expands under radiative support, forming a narrow conical funnel through which radiation escapes, resulting in low radiation efficiency. In the near-Eddington regime, the disk structure strongly depends on the magnetic field topology, allowing the system to reach a steady state as either a thin disk with magnetic coronae or a magnetically elevated disk.\u0026nbsp; These simulation results align with several observational findings and provide predictive diagnostics for future observations, which I will further elaborate on in the talk.\u0026nbsp;\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003E\u003Cstrong\u003EAbstract:\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ERadiation and magnetic fields\u0026nbsp;play crucial roles in shaping the physics of black hole accretion, especially in near- and super-Eddington regimes. To model this process, we solve the GRMHD equations coupled with angle-dependent radiation transfer, which enables us to capture the complex dynamics driven by radiation and magnetic fields in extreme environments. In the super-Eddington regime, the accretion disk thermally expands under radiative support, forming a narrow conical funnel through which radiation escapes, resulting in low radiation efficiency. In the near-Eddington regime, the disk structure strongly depends on the magnetic field topology, allowing the system to reach a steady state as either a thin disk with magnetic coronae or a magnetically elevated disk.\u0026nbsp; These simulation results align with several observational findings and provide predictive diagnostics for future observations, which I will further elaborate on in the talk.\u0026nbsp;\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"CRA Seminar | Dr. Lizhong Zhang  |Flatiron Institute | Host: Julia Speicher"}],"uid":"30957","created_gmt":"2025-03-26 19:32:50","changed_gmt":"2025-03-26 19:38:42","author":"Shaun Ashley","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2025-04-03T15:30:00-04:00","event_time_end":"2025-04-03T16:30:00-04:00","event_time_end_last":"2025-04-03T16:30:00-04:00","gmt_time_start":"2025-04-03 19:30:00","gmt_time_end":"2025-04-03 20:30:00","gmt_time_end_last":"2025-04-03 20:30:00","rrule":null,"timezone":"America\/New_York"},"location":"Gilbert Boggs Building Rm B1-44","extras":[],"hg_media":{"676685":{"id":"676685","type":"image","title":"Lizhong-Zhang-4.3.25.jpg","body":null,"created":"1743017781","gmt_created":"2025-03-26 19:36:21","changed":"1743017781","gmt_changed":"2025-03-26 19:36:21","alt":"Lizhong-Zhang-4.3.25","file":{"fid":"260502","name":"Lizhong-Zhang-4.3.25.jpg","image_path":"\/sites\/default\/files\/2025\/03\/26\/Lizhong-Zhang-4.3.25.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2025\/03\/26\/Lizhong-Zhang-4.3.25.jpg","mime":"image\/jpeg","size":7263,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2025\/03\/26\/Lizhong-Zhang-4.3.25.jpg?itok=VnkRFYaT"}}},"media_ids":["676685"],"groups":[{"id":"126011","name":"School of Physics"}],"categories":[],"keywords":[{"id":"166937","name":"School of Physics"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1795","name":"Seminar\/Lecture\/Colloquium"}],"invited_audience":[{"id":"78761","name":"Faculty\/Staff"},{"id":"177814","name":"Postdoc"},{"id":"174045","name":"Graduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}