Stellar Population and Dynamical Modeling of Galaxies with Kinematically Misaligned Components: Age and Metallicity of Structural Components
Abstract
We present stellar population and orbit modeling of two galaxies with kinematically misaligned components, PGC 35706 and LEDA 2220522, extending previous Schwarzschild dynamical models. Using spatially resolved age and metallicity maps from NBursts full spectral fitting of MaNGA data with the E-MILES grid, we solve a regularized bounded linear inverse problem that assigns light-weighted SSP-equivalent age, metallicity, and mass-to-light ratio to orbital cells in the (R,λz) plane. Component means and radial profiles use projected mass within the actual MaNGA field of view; profile segments with local component fractions below 1% are treated as weakly constrained. In LEDA 2220522, the counter-rotating disk is younger than the co-rotating disk, 1.32±0.04 versus 1.61±0.06 Gyr, and more metal-rich, [M/H]=−0.450±0.043 versus −0.613±0.024. Its rotation agrees with that of the Hα ionized gas, supporting late supply of chemically enriched retrograde gas without requiring multiple accretion episodes with alternating angular momentum. In PGC 35706, the counter-rotating disk contains 8.8% of the mass in the observed field and is formally older than the co-rotating disk by 1.36±0.51 Gyr and more metal-poor by 0.130±0.046 dex. These differences are preliminary because the projected data provide limited support. Fifty Monte Carlo realizations confirm stability of the projected maps against statistical noise, but not uniqueness in individual phase-space cells. The stellar population and orbit approach is therefore applicable to MaNGA data when local projected component fractions and systematics from regularization and the dynamical model are explicitly considered.
Related
- Dynamical Modeling of Kinematically Decoupled Galaxies: Structural Components
- Kinematically isolating intracluster light in AS1063: a distinct stellar population tracing the dark matter core
- NGC 6426: Colour-Magnitude diagram and variable star population as indicators of metallicity, distance, and age
- Distinct Population of Wolf-Rayet Stars in the Low-Metallicity Galaxy NGC 6822. Quantitative analysis of optical and UV spectra of the complete sample
- MATISSE unveils a dusty disc in the interior of EP Aquarii. First evidence of a misaligned hierarchical triple system with a central AGB star?
BibTeX
@misc{goradzhanov2026stellar,
title = {{Stellar Population and Dynamical Modeling of Galaxies with Kinematically Misaligned Components: Age and Metallicity of Structural Components}},
author = {V. S. Goradzhanov and K. O. Parfenov and D. D. Mishurin and O. K. Sil'chenko},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.05216},
eprint = {2609.05216},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.05216},
}
RIS
TY - UNPB
TI - Stellar Population and Dynamical Modeling of Galaxies with Kinematically Misaligned Components: Age and Metallicity of Structural Components
AU - V. S. Goradzhanov
AU - K. O. Parfenov
AU - D. D. Mishurin
AU - O. K. Sil'chenko
PY - 2026
DA - 2026/09/04
PB - arXiv
DO - 10.48550/arxiv.2609.05216
UR - https://arxiv.org/abs/2609.05216
AB - We present stellar population and orbit modeling of two galaxies with kinematically misaligned components, PGC 35706 and LEDA 2220522, extending previous Schwarzschild dynamical models. Using spatially resolved age and metallicity maps from NBursts full spectral fitting of MaNGA data with the E-MILES grid, we solve a regularized bounded linear inverse problem that assigns light-weighted SSP-equivalent age, metallicity, and mass-to-light ratio to orbital cells in the (R,λ_z) plane. Component means and radial profiles use projected mass within the actual MaNGA field of view; profile segments with local component fractions below 1% are treated as weakly constrained. In LEDA 2220522, the counter-rotating disk is younger than the co-rotating disk, 1.32±0.04 versus 1.61±0.06 Gyr, and more metal-rich, [M/H]=−0.450±0.043 versus −0.613±0.024. Its rotation agrees with that of the Hα ionized gas, supporting late supply of chemically enriched retrograde gas without requiring multiple accretion episodes with alternating angular momentum. In PGC 35706, the counter-rotating disk contains 8.8% of the mass in the observed field and is formally older than the co-rotating disk by 1.36±0.51 Gyr and more metal-poor by 0.130±0.046 dex. These differences are preliminary because the projected data provide limited support. Fifty Monte Carlo realizations confirm stability of the projected maps against statistical noise, but not uniqueness in individual phase-space cells. The stellar population and orbit approach is therefore applicable to MaNGA data when local projected component fractions and systematics from regularization and the dynamical model are explicitly considered.
ER -