主讲人单位 (Speaker's Institute): 波恩大学（德国）和布拉格查尔斯大学（捷克）

邀请人 (Invited by): 王龙 黄志琦

时间 (Time): 星期二, 2022/04/05 - 16:30 to 15:30

地点 (Location): Zoom/珠海校区天琴中心3416会议室

摘要 (Abstract): 

The initial mass function (IMF) is the distribution function of initial masses of all stars that form in one star formation "event", which occurs in a self-gravitating density maximum of a molecular cloud core and is thus an embedded cluster that can contain from a few stars to millions of stars. The mass of the most massive star increases monotonically with the mass of the embedded cluster. The IMF is one of the most important distribution functions in astrophysics, as it informs us how bright a newly formed stellar population is, how much it weighs and which amount of newly synthesised elements it will produce. This presentation will give some insights into our present-day understanding of the shape of the IMF and how this shape depends on the physical conditions of the star-forming gas. Recent advances question the IMF being a probability distribution function, suggesting it to be an optimal distribution function. This presentation will explain how the galaxy-wide IMF (gwIMF) is calculated in the integrated initial mass function (IGIMF) theory by adding the IMFs of all freshly formed embedded clusters. The gwIMF differs from the IMF.  Being able to calculate the systematically changing gwIMF in a galaxiy across cosmic time, allows a new understanding of the cosmological matter cycle as well as re-assessment of the probable nature of the highest-redshift quasars.

主讲人简介 (Speaker's CV): 

Prof. Dr. Pavel Kroupa obtained his PhD degree in 1992 at Trinity College as an Isaac Newton Scholar and took his first post-doctoral position in Heidelberg . He got professorship offer from the University of Bonn since 2004, obtained three offers for professorships (UF in Gainesville, Cardiff and Bonn) and has won a variety of awards for his research.

   His research interests are in dynamical properties of stellar systems (IMF, multiplicity), evolution of young multiple stellar systems in birth aggregates, star formation, dynamical evolution of open and globular clusters, spatial and kinematical distribution of stars, origin of field stars, structure and mass of the Galaxy, galactic dynamics, formation and evolution of dwarf satellite galaxies, dark matter content of galaxies.