Stellar Population and Dynamical Modeling of Galaxies with Kinematically Misaligned Components: Age and Metallicity of Structural Components

RESUMO

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 $(R,\lambda_z)$ 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, $1.32\pm0.04$ versus $1.61\pm0.06$ Gyr, and more metal-rich, $[\mathrm{M/H}]=-0.450\pm0.043$ versus $-0.613\pm0.024$. Its rotation agrees with that of the H$\alpha$ 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 $1.36\pm0.51$ Gyr and more metal-poor by $0.130\pm0.046$ 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.