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名稱Title
2020天文年會
中研院天文所 國際會議廳

論文摘要

The Radial Acceleration Relation in CLASH Galaxy Clusters

[ Oral ]

Yong Tian(Institute of Astronomy, National Central University, Taoyuan City, Taiwan (ROC)); Keiichi Umetsu(Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan); Chung-Ming Ko(Institute of Astronomy, National Central University, Taoyuan City, Taiwan (ROC); Department of Physics and Center of Complex Systems, National Central University, Taoyuan City, Taiwan (ROC)); Megan Donahue(Physics and Astronomy Department, Michigan State University, East Lansing, MI 48824, USA); I-Non Chiu(Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan)

The radial acceleration relation (RAR) in galaxies presents a tight empirical scaling law between the total and baryonic acceleration with a characteristic acceleration scale of g†=1.20×10-10 ms-2. From 20 high-mass clusters targeted by the Cluster Lensing And Supernova survey with Hubble (CLASH), we examine the existence of such a relation in galaxy clusters using weak-lensing, strong-lensing, and X-ray data sets. By combining our CLASH data with stellar mass estimates for the brightest cluster galaxies (BCGs) and accounting for the stellar baryonic component in clusters, we reveal, for the first time, an RAR on BCG--cluster scales. The resulting RAR shows the same functional relation as the low acceleration limit of the RAR in galaxies but with a higher acceleration scale g‡=2.0×10-9 ms-2. We find that the new RAR in CLASH clusters is consistent with the semi-analytical model developed in the standard ΛCDM framework. Our results also imply a baryonic Faber--Jackson relation on cluster scales.