Morphological Evolution of Disk Galaxies and Their Concentration, Asymmetry, and Clumpiness (CAS) Properties in Simulations across Toomre’s Q Parameter
Issued Date
2024-04-01
Resource Type
ISSN
0004637X
eISSN
15384357
Scopus ID
2-s2.0-85189985200
Journal Title
Astrophysical Journal
Volume
965
Issue
1
Rights Holder(s)
SCOPUS
Bibliographic Citation
Astrophysical Journal Vol.965 No.1 (2024)
Suggested Citation
Chantavat T., Yuma S., Malelohit P., Worrakitpoonpon T. Morphological Evolution of Disk Galaxies and Their Concentration, Asymmetry, and Clumpiness (CAS) Properties in Simulations across Toomre’s Q Parameter. Astrophysical Journal Vol.965 No.1 (2024). doi:10.3847/1538-4357/ad3218 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/97993
Title
Morphological Evolution of Disk Galaxies and Their Concentration, Asymmetry, and Clumpiness (CAS) Properties in Simulations across Toomre’s Q Parameter
Author(s)
Author's Affiliation
Corresponding Author(s)
Other Contributor(s)
Abstract
We investigate the morphological and structural evolution of disk galaxies in simulations for a wide range of Toomre’s Q parameters. In addition to the inspection of conventional bar modes, we compute the concentration, asymmetry, and clumpiness (CAS) parameters to enlarge the understanding of the galaxy evolution. These parameters are widely employed to analyze the light distribution of the observed galaxies, but the adaptation to numerical simulations is not much considered. While the bar formation takes place in a considerable range of Q around 1, barred galaxies originating from Q > 1 and Q < 1 disks yield CAS values that differ significantly. Disks starting with Q < 1 develop clumps due to local gravitational instabilities along with the bar, and these clumps play a central role in enhancing the CAS values. This process is absent in the Q > 1 counterparts in which the evolution is dominated by linearly unstable two-armed modes that lead to lower CAS values. Likewise, unbarred galaxies that are obtainable from disks with Q far below and far above 1 exhibit greatly different CAS magnitudes. It turns out that the CAS parameters can serve as indicators of the initial kinematical state and the evolution history of a disk of any morphology. In addition, we find an alternative mechanism of the formation of the lopsided barred galaxy when Q ≲ 1. Bars that evolve in the midst of the clumps can spontaneously become lopsided at the end.