Star-Gas Misalignment in Galaxies. I. the Properties of Galaxies from the Horizon-AGN Simulation and Comparisons to SAMI

Donghyeon J. Khim, Sukyoung K. Yi, Yohan Dubois, Julia J. Bryant, Christophe Pichon, Scott M. Croom, Joss Bland-Hawthorn, Sarah Brough, Hoseung Choi, Julien Devriendt, Brent Groves, Matt S. Owers, Samuel N. Richards, Jesse Van De Sande, Sarah M. Sweet

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Recent integral field spectroscopy observations have found that about 11% of galaxies show star-gas misalignment. The misalignment possibly results from external effects such as gas accretion, interaction with other objects, and other environmental effects, hence providing clues to these effects. We explore the properties of misaligned galaxies using Horizon-AGN, a large-volume cosmological simulation, and compare the results with those of the Sydney-AAO Multi-object integral field spectrograph (SAMI) Galaxy Survey. Horizon-AGN can match the overall misalignment fraction and reproduces the distribution of misalignment angles found by observations surprisingly closely. The misalignment fraction is found to be highly correlated with galaxy morphology both in observations and in the simulation: early-type galaxies are substantially more frequently misaligned than late-type galaxies. The gas fraction is another important factor associated with misalignment in the sense that misalignment increases with decreasing gas fraction. However, there is a significant discrepancy between the SAMI and Horizon-AGN data in the misalignment fraction for the galaxies in dense (cluster) environments. We discuss possible origins of misalignment and disagreement.

Original languageEnglish
Article number106
JournalAstrophysical Journal
Issue number2
Publication statusPublished - 2020 May 10

Bibliographical note

Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved.

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Star-Gas Misalignment in Galaxies. I. the Properties of Galaxies from the Horizon-AGN Simulation and Comparisons to SAMI'. Together they form a unique fingerprint.

Cite this