On the robustness of triaxial Schwarzschild modelling: The effects of correcting the orbit mirroring

Abstract

In the past 15 years, the triaxial Schwarzschild orbit-superposition code by van den Bosch et al. (2008) has been widely applied to study the dynamics of galaxies. Recently, Quenneville et al. (2022) reported a bug in the orbit calculation of this code, specifically in the mirroring procedure that is used to speed up the computation. We have fixed the incorrect mirroring in DYNAMITE, which is the publicly-released successor of the triaxial Schwarzschild code by van den Bosch et al. (2008). In this study, we provide a thorough quantification of how this bug has affected the results of dynamical analyses performed with this code. We compare results obtained with the original and corrected versions of DYNAMITE, and discuss the differences in the phase-space distribution of a single orbit and in the global stellar orbit distribution, in the mass estimate of the central black hole in the highly triaxial galaxy PGC 46832, and in the measurement of intrinsic shape and enclosed mass for more than 50 galaxies. Focusing on the typical scientific applications of a Schwarzschild triaxial code, in all our tests we find that differences are negligible with respect to the statistical and systematic uncertainties. We conclude that previous results with the van den Bosch et al. (2008) triaxial Schwarzschild code are not significantly affected by the incorrect mirroring.

14 pages, 11 figures. Submitted to A&A

References in corpus (26)

• The SAURON project -- X. The orbital anisotropy of elliptical and lenticular galaxies: revisiting the (V/sigma,epsilon) diagram with integral-field stellar kinematics
• Measuring the inclination and mass-to-light ratio of axisymmetric galaxies via anisotropic Jeans models of stellar kinematics
• Triaxial orbit based galaxy models with an application to the (apparent) decoupled core galaxy NGC 4365
• The Black Hole Mass, Stellar M/L, and Dark Halo in M87
• Unification of the Fundamental Plane and Super-Massive Black Holes Masses
• Dynamical modelling of luminous and dark matter in 17 Coma early-type galaxies
• The SAMI Galaxy Survey: the third and final data release
• Orbital decomposition of CALIFA spiral galaxies
• Dark matter content and internal dynamics of NGC 4697: NMAGIC particle models from slit data and planetary nebulae velocities
• Combining Stellar Populations with Orbit-Superposition Dynamical Modelling - the Formation History of the Lenticular Galaxy NGC 3115
• The Fornax3D project: Tracing the assembly history of the cluster from the kinematic and line-strength maps
• Recovery of the internal orbital structure of galaxies
• A new implementation of the Schwarzschild method for constructing observationally-driven dynamical models of galaxies of all morphological types
• The SAMI Galaxy Survey: The internal orbital structure and mass distribution of passive galaxies from triaxial orbit-superposition Schwarzschild models
• Six new supermassive black hole mass determinations from adaptive-optics assisted SINFONI observations
• The Fornax3D project: Assembly histories of lenticular galaxies from a combined dynamical and population orbital analysis
• A novel approach to optimize the regularization and evaluation of dynamical models using a model selection framework
• The Fornax3D project: discovery of ancient massive merger events in the Fornax cluster galaxies NGC 1380 and NGC 1427
• The MASSIVE Survey -- XV. A Stellar Dynamical Mass Measurement of the Supermassive Black Hole in Massive Elliptical Galaxy NGC 1453
• Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453
• A low upper mass limit for the central black hole in the late-type galaxy NGC 4414
• The Black Hole Mass of NGC 4151 from Stellar Dynamical Modeling
• The MASSIVE Survey -- XVII. A Triaxial Orbit-based Determination of the Black Hole Mass and Intrinsic Shape of Elliptical Galaxy NGC 2693
• Dynamical modelling of the twisted galaxy PGC 046832
• BAYES-LOSVD: a bayesian framework for non-parametric extraction of the line-of-sight velocity distribution of galaxies
• Comparing Lensing and Stellar Orbital Models of a Nearby Massive Strong-Lens Galaxy

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• MaNGA DynPop -- III. Stellar dynamics versus stellar population relations in 6000 early-type and spiral galaxies: Fundamental Plane, mass-to-light ratios, total density slopes, and dark matter fractions
• The SAMI Galaxy Survey: Environmental analysis of the orbital structures of passive galaxies
• Orbit-Superposition Dynamical Modeling of Barred Galaxies
• The Fornax3D project: Environmental effects on the assembly of dynamically cold disks in Fornax cluster galaxies
• Effect of the initial mass function on the dynamical SMBH mass estimate in the nucleated early-type galaxy FCC 47
• Quantifying the stellar ages of dynamically separated bulges and disks of CALIFA spiral galaxies
• Equilibrium dynamical models in the inner region of the Large Magellanic Cloud based on Gaia DR3 kinematics
• Rediscovering the Milky Way with orbit superposition approach and APOGEE data I. Method validation
• The diverse physical origins of stars in the dynamically hot bulge: CALIFA vs. IllustrisTNG
• Decomposing galaxies with BANG: an automated morpho-kinematical decomposition of the SDSS-DR17 MaNGA survey
• The SAMI Survey: Evidence for dynamical coupling of ionised gas and young stellar populations
• Uncover 3D Dark Matter Distribution of the Milky Way by an Empirical Triaxial Orbit-Superposition Model: Method Validation
• Spatially resolved stellar-to-total dynamical mass relation: Radial variations, gradients and profiles of galaxy stellar populations