Massive central galaxies of galaxy groups in the Romulus simulations: an overview of galaxy properties at z = 0

S. Lyla Jung, Douglas Rennehan, Vida Saeedzadeh, Arif Babul, Michael Tremmel, Thomas R. Quinn, S. Ilani Loubser, E. O'Sullivan, Sukyoung K. Yi

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Contrary to many stereotypes about massive galaxies, observed brightest group galaxies (BGGs) are diverse in their star formation rates, kinematic properties, and morphologies. Studying how they evolve into and express such diverse characteristics is an important piece of the galaxy formation puzzle. We use a high-resolution cosmological suite of simulations Romulus and compare simulated central galaxies in group-scale haloes at z = 0 to observed BGGs. The comparison encompasses the stellar mass-halo mass relation, various kinematic properties and scaling relations, morphologies, and the star formation rates. Generally, we find that Romulus reproduces the full spectrum of diversity in the properties of the BGGs very well, albeit with a tendency toward lower than the observed fraction of quenched BGGs. We find both early-type S0 and elliptical galaxies as well as late-type disc galaxies; we find Romulus galaxies that are fast-rotators as well as slow-rotators; and we observe galaxies transforming from late-type to early-type following strong dynamical interactions with satellites. We also carry out case studies of selected Romulus galaxies to explore the link between their properties, and the recent evolution of the stellar system as well as the surrounding intragroup/circumgalactic medium. In general, mergers/strong interactions quench star-forming activity and disrupt the stellar disc structure. Sometimes, however, such interactions can also trigger star formation and galaxy rejuvenation. Black hole feedback can also lead to a decline of the star formation rate but by itself, it does not typically lead to complete quenching of the star formation activity in the BGGs.

Original languageEnglish
Pages (from-to)22-47
Number of pages26
JournalMonthly Notices of the Royal Astronomical Society
Volume515
Issue number1
DOIs
Publication statusPublished - 2022 Sept 1

Bibliographical note

Publisher Copyright:
© 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'Massive central galaxies of galaxy groups in the Romulus simulations: an overview of galaxy properties at z = 0'. Together they form a unique fingerprint.

Cite this