|Welcome to Prof. Sukyoung K. Yi's group (GEM) homepage
이석영 교수의 은하진화 연구 그룹 홈페이지에 오신것을 환영합니다.
The ultimate goal of our group is to understand the formation and evolution of galaxies. We work on various versions of galaxy formation theories, focusing on dynamical clustering of galaxies and galactic chemical evolution in combination with stellar population synthesis. We extensively, but not exclusively, use SDSS and GALEX data to test our theoretical models.
The 2020 GEM 2nd workshop will be held on 19 - 21 August, 2020 in Yonsei University, Seoul, Korea (Cancelled)
The 2020 GEM workshop will be held on 14 - 17 January, 2020 in Gyeongju, Korea
Minjung Park's paper has been introduced by AAS Nova (23 September 2019).
Dr. Sandro Tacchella will visit GEM (8-11 July, 2019)
The 2019 GEM - CASCADE workshop will be held on 1 - 4 July, 2019 in Jeju, Korea
The 2018 GEM workshop will be held on 2 - 4 July, 2018 in Kangnung, Korea
Dr. Scott Croom, Dr. Julia Bryant and Dr. Warrick Couch will visit GEM (10-13 Apr 2017)
Dr. Barbara Cantinella and Dr. Luca Cortese at ICRAR are visiting GEM (1-15 Apr 2017)
SAMI workshop will be held at KASI. (12 Apr 2017)
Environment workshop wiil be held. (3 Apr 2017)
Dr. Kang Xi and Dr. Emanuel Contini from the Purple Mountain Observatory (PMO) will visit GEM (9-13 May 2016) (See the poster)
Prof. Christophe Pichon at IAP and his group members visited GEM (12 Feb 2016)
Dr. Sanjaya Paudel visited GEM (22 Jan 2016)
GEM group members participated in the 227th AAS meeting in Florida giving presentations (05-09 Jan 2016)
The former GEMer Kyuseok Oh has been awarded "A best thesis at Yonsei". Congratulations to Dr. Oh! (Nov 2015)
Honggeun Khim has been awarded "The Jung Sung Ki Alumnus award" for excellent research performance. Congratulations to Khim! (Nov 2015)
YZiCS: Unveiling the Quenching History of Cluster Galaxies Using Phase-space Analysis
This study tries to constrain the quenching timescales of galaxies in local cluster environments by combining a cosmological simulation data (YZiCS) with an SDSS cluster catalog through the phase-space analysis.
The star formation history for the sample galaxies are constrained by using abundance matching between the time since infall distribution and the star formation rate distribution of the galaxies
The following are our main results on the constrained quenching timescales.
(i) Part of the quenching takes place outside clusters by consuming cold gas with the e-folding timescale of 3 Gyr with a strong inverse mass dependence.
(ii) The pace of quenching is maintained roughly for 2 Gyr ("delay time") during the first crossing time into the cluster.
(iii) Quenching becomes more dramatic (e-folding timescale of roughly 1 Gyr) after delay time, probably because ram pressure stripping is strongest near the cluster center.
Counterintuitively, more massive galaxies show shorter quenching timescales mainly because they enter their clusters with lower gas fractions due to ex-situ quenching in the first place.
Full text [ArXiv]
Full text [ADS]