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Physics Department Sharif University of Technology Cosmology Group Weekly Seminars |
دانشکده فیزیک دانشگاه صنعتی شریف
سمینارهای هفتگی گروه کیهان شناسی
**لطفا به زمان و مکان سمینار توجه فرمایید**
سمینار به صورت هیبریدی (حضوری و مجازی) برگزار می شود
Formation of Multiple Stellar Populations in globular clusters
Asiyeh Yaghoobi
Department of Physics, Ferdowsi University of Mashhad
Abstract:
Globular clusters (GCs) can provide useful information from the early star-forming subsystems to study the formation history of their parent galaxies. They are composed of low-metal ([Fe/H] <1), low-mass (< 0.8 Msun), and old (> 10 Gyr) stars. Traditionally, it was assumed that all stars in GCs have similar chemical compositions to the initial cloud from which GCs and host galaxies have already been formed. However, recent observations have revealed that stars within GCs display anomalous variations in light elements (e. g. He, C, N, O, Na, Al, and sometimes Mg) that are not expected to occur inside the low-mass stars of GCs. These populations with anomalous abundance variations in GCs are known as "Multiple Stellar Populations" (MSPs) or second generation (SG), and their formation is still shrouded in mystery. In this talk, I investigate the formation of MSPs within young clusters using 3D hydrodynamical simulations in the context of the asymptotic giant branch (AGB) scenario. I will start by introducing the AGB model and then explain some proposed problems for this scenario, such as ram pressure and ionizing radiation. After that, I will present our most important results based on the two papers below. Our results imply that the formation of SG stars in the AGB scenario needs to occur within massive star clusters located in dense environments, consistent with properties of the ambient surrounding of GCs in star-forming disk galaxies observed at redshift z > 2.
https://ui.adsabs.harvard.edu/abs/2022MNRAS.517.4175Y/abstract
https://ui.adsabs.harvard.edu/abs/2022MNRAS.510.4330Y/abstract
یکشنبه 7 اسفند 1401، ساعت 17:00
Sunday 26 February 2023 – 17:00 Tehran Time
Hybrid Seminar
آمفی تئاتر دانشکده فیزیک-تالار جنابPhysics Department – Amphitheater- Jenab Hall/
https://vc.sharif.edu/ch/cosmology
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