再電離重力透鏡質量團調查計劃中紫外光度函數的研究

再電離重力透鏡質量團調查計劃中紫外光度函數的研究


Public Seminar of Research Postgraduate Programmes Student:- Study of UV Luminosity Function in Reionization Lensing Cluster Survey 

Galaxy formation is tightly related with dark matter halo formation, which varies in different dark matter models. Particularly, it is known that in terms of small scale structures, wave dark matter model(ψDM) produces flat solitonic cores which are compatible with observed dwarf spheroidal galaxies different from cuspy cores predicted in cold dark matter model(CDM). Ultraviolet luminosity function (UV LF) harboring volume number density of star forming galaxies across luminosity in different epochs would thus serve as a quantitative representation for dark matter models. It has been proved previously that surface number density of galaxies and magnification bias in cluster fields of Hubble Frontier Field(HFF) supports UV LF with faint end turnover derived from ψDM, instead of galaxy buildup at the faint end in UV LF of CDM.

Built on the success with HFF, we would like to extend the study on magnification bias and reconstructed UV LF to observations made in Reionization lensing Cluster Survey(RELICS) and enlarge the number of galaxy samples. Consisting of 42 cluster fields and 18 parallel fields(compared with 6 cluster and parallel fields respectively in HFF), RELICS could mitigate uncertainty brought by cosmic variance in surface number density of galaxies, thereby providing more solid evidence in supporting the ψDM scenario.
 
時間:2019.05.03(五) 17:00
地點:香港大學 莊月明物理樓522室
講者:Wai Kuen CHAN(香港大學)
語言:英語

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此活動由香港大學物理系主辦。