BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:QMS International Lecture Series DTSTART:20261029T010000Z DTEND:20261030T123000Z DTSTAMP:20260915T095200Z UID:indico-event-5695@indico2.riken.jp DESCRIPTION:Speakers: Hiroko Okada (NAOJ)\, Wako Aoki (National Astronomic al Observatory of Japan)\, Shunji NISHIMURA (RIKEN)\, Nobuya Nishimura (Ko gakuin University)\n\nEvent Overview\n\n\nSubject: Galactic Chemical Evolu tion\n\n\nLecturer: Prof. Chiaki Kobayashi (University of Hertfordshire)\n \n\nDate: 29-30 Oct. 2026\n\n\nVenue: Mitaka Campus NAOJ (National Astrono mical Observatory of Japan)On-site participation is encouraged\, but onlin e participation via Zoom will also be available for registrants. Please no te that online access via Zoom will be provided on a best-effort basis.\n\ n\nExpected Audience: PhD students\, early-career researchers\, and non-sp ecialist researchers interested in stellar nucleosynthesis and galactic ch emical evolution\n\n\nRegistration Deadline: 21 Oct. 2026 (JST)\n\n\n \nT his lecture will be followed by the OMEG18 conference at RIKEN (Oct. 20 –23).\n \n\n \nAbstract\nDuring the Big Bang\, only light elements suc h as hydrogen and helium were produced. Carbon and heavier elements (calle d metals in astronomy) are created inside stars and are ejected when they die. Iron-peak and neutron-capture elements are further produced by binari es - Type Ia supernovae and neutron star mergers\, respectively. These ele ments are distributed into the interstellar medium\, and new stars formed from this gas contain elements produced by previous generations of stars. Therefore\, stars are fossils that retain the history of their host galaxy . Detailed elemental abundances of individual stars in the Milky Way have been extremely useful for constraining stellar nucleosynthesis and the ori gin of elements. Not only metallicities but also elemental abundance ratio s evolve in galaxies\, which can be used to constrain stellar astrophysics and galaxy evolution.In our zoom-in simulation of a Milky Way type galaxy \, the basic structures of the Galaxy and their stellar populations are re produced very well\; the bulge formed by the assembly of small gas-rich ga laxies at high-redshifts has old and high-alpha stellar populations\, whil e the disk formed inside-out with a longer timescale has younger and lower -alpha stellar populations due to the delayed enrichment from Type Ia supe rnovae\, which results in the bimodal distribution of the alpha-to-iron ra tios observed in the Milky Way Galaxy and M31 Andromeda Galaxy. For the el ements heavier than iron\, it is not possible to reproduce observations wi th neutron star mergers only and the contributions from magneto-rotational supernovae is required.In large-scale cosmological simulations\, includin g feedback from active galactic nuclei that originate the first stars\, ch emical and dynamical properties of various types of galaxies are fairly we ll reproduced. Metallicity is higher in more massive galaxies (leading to the mass-metallicity relation)\, and at the centre of galaxies (causing me tallicity radial gradients)\, broadly following elemental abundance trends expected by nuclear astrophysics. With the James Webb Space Telescope\, u nexpected elemental-abundance ratios (namely high N/O) are detected for ve ry high redshift star-forming galaxies\, which can be explained with Wolf- Rayet stars under intermittent star formation. Comparing various elemental abundances (CNO\, Ne\, and Ar) to the galactic chemical evolution models\ , it will be possible to confirm the dominant enrichment source as well as constraining galaxy formation processes across Cosmic Time.\n \nLecturer \nProf. Chiaki Kobayashi\nProfessor at the University of Hertfordshire. Sh e was awarded her B.Sc. and Ph.D. in Astronomy *from* the University of To kyo. After research appointments at the Max Planck Institute for Astrophys ics and Australian National University\, she joined the University of Hert fordshire\, where he currently serves as Professor. Her research focuses o n the formation and evolution of galaxies and the origin of the chemical e lements in the Universe\, using large-scale supercomputer simulations. She is a co-author of the book How Were the Elements Made? — Supernova Expl osions and the Chemical Evolution of the Universe (Iwanami Lecture Series: The World of Physics). She is currently a Visiting Senior Scientist at th e Kavli Institute for the Physics and Mathematics of the Universe. She als o serves as the coordinator of BRIDGECE\, the UK network for nuclear astro physics. In 2024\, she was awarded the George Darwin Lectureship by the Ro yal Astronomical Society.\nOrganizers\n\nWako Aoki (NAOJ)\nHiroko Okada (N AOJ)\nNobuya Nishimura (Kogakuin U)\nShunji Nishimura (RIKEN)\n\nSupport\n \nQuantum Matter Science in the Universe Opened Up by Precise Numerical Ca lculations (QMS)\nNational Astronomical Observatory of Japan (NAOJ)\nRiNA- Net (RIKEN international Nuclear Astrophysics Network)\nUKAKUREN (Japan Fo rum of Nuclear Astrophysics)\n\n\n\nhttps://indico2.riken.jp/event/5695/ IMAGE;VALUE=URI:https://indico2.riken.jp/event/5695/logo-1736729801.png LOCATION:NAOJ URL:https://indico2.riken.jp/event/5695/ END:VEVENT END:VCALENDAR