Dynamical Modeling of Kinematically Decoupled Galaxies: Structural Components
Abstract
We present the results of dynamical modeling of two galaxies with inconsistent kinematics -- PGC 35706 and LEDA 2220522 -- using data from the MaNGA integral-field spectroscopic survey and deep photometry from the DESI Legacy Imaging Surveys. The Schwarzschild orbit-superposition method in the axisymmetric approximation was employed to identify structural components based on the orbital circularity parameter λz. Three components have been identified in the galaxies: a spheroidal (bulge/halo) component and co-rotating and counter-rotating stellar disks. The spheroidal component dominates by mass in both galaxies: about 60\% in PGC 35706 and 51\% in LEDA 2220522; the contributions of the co-rotating and counter-rotating disks are 29\% and 9\% in PGC 35706 and 30\% and 18\% in LEDA 2220522, respectively. The kinematics of the ionized gas in both galaxies is consistent with the rotation of the counter-rotating disk, indicating that it formed from externally accreted gas with opposite angular momentum. The results support a scenario in which counter-rotating disks form through gas accretion from the intergalactic medium or through minor mergers with gas-rich satellites. This work demonstrates the effectiveness of the Schwarzschild method for studying the complex kinematic structure of galaxies and their formation history.
Versions
Related
- Stellar Population and Dynamical Modeling of Galaxies with Kinematically Misaligned Components: Age and Metallicity of Structural Components
- Disentangling the assembly of the central and diffuse stellar components in galaxy clusters through dynamical friction and tidal stripping
- Disentangling the assembly of the central and diffuse stellar components in galaxy clusters through dynamical friction and tidal stripping
- XRISM Reveals a Kinematically Coherent Core System of the Nearby Cool-Core Cluster Abell 2199
- Ellipsoidal Modeling Framework for TNOs: the triaxial shape of (50000) Quaoar and its implications for Weywot and the dynamical environment
BibTeX
@misc{goradzhanov2026dynamical,
title = {{Dynamical Modeling of Kinematically Decoupled Galaxies: Structural Components}},
author = {V. S. Goradzhanov and D. D. Mishurin and O. K. Sil'chenko and D. F. Gasymov},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.28388},
eprint = {2608.28388},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.28388},
}
RIS
TY - UNPB
TI - Dynamical Modeling of Kinematically Decoupled Galaxies: Structural Components
AU - V. S. Goradzhanov
AU - D. D. Mishurin
AU - O. K. Sil'chenko
AU - D. F. Gasymov
PY - 2026
DA - 2026/08/28
PB - arXiv
DO - 10.48550/arxiv.2608.28388
UR - https://arxiv.org/abs/2608.28388
AB - We present the results of dynamical modeling of two galaxies with inconsistent kinematics -- PGC 35706 and LEDA 2220522 -- using data from the MaNGA integral-field spectroscopic survey and deep photometry from the DESI Legacy Imaging Surveys. The Schwarzschild orbit-superposition method in the axisymmetric approximation was employed to identify structural components based on the orbital circularity parameter λ_z. Three components have been identified in the galaxies: a spheroidal (bulge/halo) component and co-rotating and counter-rotating stellar disks. The spheroidal component dominates by mass in both galaxies: about 60\% in PGC 35706 and 51\% in LEDA 2220522; the contributions of the co-rotating and counter-rotating disks are 29\% and 9\% in PGC 35706 and 30\% and 18\% in LEDA 2220522, respectively. The kinematics of the ionized gas in both galaxies is consistent with the rotation of the counter-rotating disk, indicating that it formed from externally accreted gas with opposite angular momentum. The results support a scenario in which counter-rotating disks form through gas accretion from the intergalactic medium or through minor mergers with gas-rich satellites. This work demonstrates the effectiveness of the Schwarzschild method for studying the complex kinematic structure of galaxies and their formation history.
ER -