Impact of galaxy mergers on the colours of cluster galaxies

Sree Oh, Keunho Kim, Joon Hyeop Lee, Minjin Kim, Yun Kyeong Sheen, Jinsu Rhee, Chang H. Ree, Hyunjin Jeong, Luis C. Ho, Jaemann Kyeong, Eon Chang Sung, Byeong Gon Park, Sukyoung K. Yi

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


We examine the ultraviolet and optical colours of 906 cluster galaxies from the KASI-Yonsei Deep Imaging Survey of Clusters (KYDISC). The sample has been divided into two categories, morphologically disturbed and undisturbed galaxies, based on the visual signatures related to recent mergers. We find that galaxies with signatures of recent mergers show significantly bluer colours than undisturbed galaxies. Disturbed galaxies populate more on the cluster outskirts, suggesting recent accretion into the cluster environment, which implies that disturbed galaxies can be less influenced by the environmental quenching process and remain blue. However, we still detect bluer colours of disturbed galaxies in all locations (cluster core and outskirts) for the fixed morphology, which is difficult to understand just considering the difference in time since infall into a cluster. Moreover, blue disturbed galaxies show features seemingly related to recent star formation. Therefore, we suspect that mergers make disturbed galaxies keep their blue colour longer than undisturbed galaxies under the effect of the environmental quenching through either merger-induced star formation or central gas concentration which is less vulnerable for gas stripping.

Original languageEnglish
Pages (from-to)4169-4180
Number of pages12
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
Publication statusPublished - 2019 Sept 21

Bibliographical note

Publisher Copyright:
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


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