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Welcome to Yonsei Observable UNiverse Group (YOUNG, 연세관측우주론그룹)

	Group leader Myungkook James Jee (지명국), mkjee@yonsei.ac.kr Professor in Department of Astronomy, Yonsei University Ph.D. from Johns Hopkins University Research interests: - gravitational strong & weak lensing - astronomical instrumentation - observational cosmology and nature of dark matter - galaxy cluster plasma physics - machine learning

Publication in ADS
Google scholar

Research highlights

	Dark matter in the Coma Cluster region. The distribution of dark matter calculated based on this research (dark green cloud) is overlayed on an image of the Coma Cluster and more distant background galaxies taken by the Subaru Telescope. Strands of dark matter can be seen extending millions of light years.
	ICL fraction evolution. Filled red circles are the current results. We extrapolated the best-fit Sérsic profiles to the same aperture to estimate the total ICL flux. The dashed line and pink shade show the best-fit linear regression and its 68% uncertainty, respectively. We weighted all data points equally and adjusted them in such a way that the reduced χ2 value becomes unity. The comparison between our high-redshift and the literature low-redshift samples shows that there is no significant evolution of the ICL fraction with redshift in observation, which contradicts the current theoretical prediction.

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-<strong>Welcome to Yonsei Observable UNiverse Group (YOUNG)</strong>
+<strong>Welcome to Yonsei Observable UNiverse Group ([[YOUNG]], 연세관측우주론그룹)</strong>
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-| [[File:mkjee.jpg|200px]] || Group leader <br> Myungkook James Jee (지명국), mkjee@yonsei.ac.kr <br> Professor in Department of Astronomy, Yonsei University <br> Ph.D. from Johns Hopkins University <br> Research interests: <br> - gravitational strong & weak lensing <br> - astronomical instrumentation <br> - observational cosmology and nature of dark matter <br> - galaxy cluster plasma physics <br> - machine learning
+| [[File:Mkjee.jpg|200px]] || Group leader <br> Myungkook James Jee (지명국), mkjee@yonsei.ac.kr <br> Professor in Department of Astronomy, Yonsei University <br> Ph.D. from Johns Hopkins University <br> Research interests: <br> - gravitational strong & weak lensing <br> - astronomical instrumentation <br> - observational cosmology and nature of dark matter <br> - galaxy cluster plasma physics <br> - machine learning
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+<br>
+{| class="wikitable" style="margin:auto"
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+| [[File:young_beach.jpg|180px]] || [[File:young_638.jpg|160px]] || [[File:young_library.jpg|160px]] ||[[File:young_neworleans.jpg|158px]]
+|-
+|}
 [https://ui.adsabs.harvard.edu/search/filter_database_fq_database=OR&filter_database_fq_database=database%3A%22astronomy%22&filter_property_fq_property=AND&filter_property_fq_property=property%3A%22refereed%22&format=SHORT&fq=%7B!type%3Daqp%20v%3D%24fq_database%7D&fq=%7B!type%3Daqp%20v%3D%24fq_property%7D&fq_database=(database%3A%22astronomy%22)&fq_property=(property%3A(%22refereed%22))&q=%3Dauthor%3A(%22jee%2C%20myungkook%20j.%22%20OR%20%22jee%2C%20j%22%20OR%20%22jee%2C%20m.%20j.%22%20OR%20%22jee%2C%20m.%20james%22%20OR%20%22jee%2C%20james%22)%20AND%20pubdate%3A%5B2005-01%20TO%20*%5D%20OR%20author%3A%22James%20Jee%2C%20M.%22&sort=date%20desc%2C%20bibcode%20desc&unprocessed_parameter=qform&unprocessed_parameter=adsobj_query&p_=0 Publication in ADS] <br>
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 <strong>Research highlights</strong>
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-| [[File:na2024.jpg|500px]] || The concordance cosmological model predicts that galaxy clusters grow at the intersection of filaments that structure the cosmic web and extend tens of megaparsecs. Although this hypothesis has been supported by the baryonic components, no observational study has detected the dark matter component of the intracluster filaments (ICFs), the terminal segment of the large-scale cosmic filaments at their conjunction with individual clusters. We report weak-lensing detection of ICFs in the Coma cluster field from the ∼12-deg2 Hyper Suprime-Cam imaging data. The detection is based on two methods, the matched-filter technique and the shear-peak statistic. The matched-filter technique yields detection significances of 6.6σ and 3.6σ for the northern and western ICFs at 110° and 340°, respectively. The shear-peak statistic yields detection significances of 3.1σ and 2.8σ for these ICFs. Both ICFs are highly correlated with the overdensities in the weak-lensing mass reconstruction and are well aligned with the known large-scale (>10 Mpc) cosmic filaments associated with the Coma supercluster.
+| [[File:na2024.jpg|400px]] || style="padding: 50px" |[[File:coma.jpg|300px]]
+<br> Dark matter in the Coma Cluster region. The distribution of dark matter calculated based on this research (dark green cloud) is overlayed on an image of the Coma Cluster and more distant background galaxies taken by the Subaru Telescope. Strands of dark matter can be seen extending millions of light years.
 |-
+| [[File:nature2023.jpg|400px]] || style="padding: 50px" |[[File:icl_evolution.jpg|300px]]
+<br>
+ICL fraction evolution. Filled red circles are the current results. We extrapolated the best-fit Sérsic profiles to the same aperture to estimate the total ICL flux. The dashed line and pink shade show the best-fit linear regression and its 68% uncertainty, respectively. We weighted all data points equally and adjusted them in such a way that the reduced χ2 value becomes unity. The comparison between our high-redshift and the literature low-redshift samples shows that there is no significant evolution of the ICL fraction with redshift in observation, which contradicts the current theoretical prediction.
 |}

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