NMAGIC: Fast Parallel Implementation of a Chi-Squared-Made-to-Measure Algorithm for Modelling Observational Data

Abstract

We describe a made-to-measure algorithm for constructing N-particle models of stellar systems from observational data (Chi-Squared-M2M), extending earlier ideas by Syer and Tremaine. The algorithm properly accounts for observational errors, is flexible, and can be applied to various systems and geometries. We implement this algorithm in a parallel code NMAGIC and carry out a sequence of tests to illustrate its power and performance: (i) We reconstruct an isotropic Hernquist model from density moments and projected kinematics and recover the correct differential energy distribution and intrinsic kinematics. (ii) We build a self-consistent oblate three-integral maximum rotator model and compare how the distribution function is recovered from integral field and slit kinematic data. (iii) We create a non-rotating and a figure rotating triaxial stellar particle model, reproduce the projected kinematics of the figure rotating system by a non-rotating system of the same intrinsic shape, and illustrate the signature of pattern rotation in this model. From these tests we comment on the dependence of the results from Chi-Squared-M2M on the initial model, the geometry, and the amount of available data.

20 pages, 23 figures, accepted for MNRAS

References in corpus (19)

• Constraints from Dynamical Friction on the Dark Matter Content of Barred Galaxies
• Axisymmetric Dynamical Models of the Central Regions of Galaxies
• Dynamical Modeling of Velocity Profiles: The Dark Halo Around the Elliptical Galaxy NGC2434
• The counterrotating core and the black hole mass of IC1459
• Made-to-measure N-body systems
• Difficulties with Recovering The Masses of Supermassive Black Holes from Stellar Kinematical Data
• A SAURON study of M32: measuring the intrinsic flattening and the central black hole mass
• Axisymmetric Three-Integral Models for Galaxies
• Dynamics of Stars and Globular Clusters in M87
• Regularized orbit models unveiling the stellar structure and dark matter halo of the Coma elliptical NGC 4807
• Axisymmetric galaxy models wth central BHs, with an application to M32
• Bars and Dark Matter Halo Cores
• Large-Scale Model of the Milky Way: Stellar Kinematics and Microlensing Event Timescale Distribution in the Galactic Bulge
• Velocity profiles of Osipkov-Merritt models
• Axisymmetric dynamical models for SAURON and OASIS observations of NGC 3377
• Dynamics of the Boxy Elliptical Galaxy NGC 1600
• General solution of the Jeans equations for triaxial galaxies with separable potentials
• The Dynamical Inverse Problem for Axisymmetric Stellar Systems
• An Axisymmetric Distribution Function for the Galactic Bulge

Cited by in corpus (107)

• The Atlas3D project - XV. Benchmark for early-type galaxies scaling relations from 260 dynamical models: mass-to-light ratio, dark matter, Fundamental Plane and Mass Plane
• Measuring the inclination and mass-to-light ratio of axisymmetric galaxies via anisotropic Jeans models of stellar kinematics
• The Local Dark Matter Density
• Dynamical modelling of the Galactic bulge and bar: the Milky Way's bar pattern speed, stellar, and dark matter mass distribution
• Galaxy Masses
• Kinematic properties of early-type galaxy haloes using planetary nebulae
• Made-to-Measure models of the Galactic Box/Peanut bulge: stellar and total mass in the bulge region
• The mass of the black hole in Centaurus A from SINFONI AO-assisted integral-field observations of stellar kinematics
• Kinematics of the old stellar population at the Galactic Center
• Dearth of dark matter or massive dark halo? Mass-shape-anisotropy degeneracies revealed by NMAGIC dynamical models of the elliptical galaxy NGC 3379
• Revisiting the Tale of Hercules: how stars orbiting the Lagrange points visit the Sun
• Orbital structure of merger remnants: Trends with gas fraction in 1:1 mergers
• Internal kinematics and dynamical models of dwarf spheroidal galaxies around the Milky Way
• The Gravitational Force Field of the Galaxy Measured From the Kinematics of RR Lyrae in Gaia
• Dark matter content and internal dynamics of NGC 4697: NMAGIC particle models from slit data and planetary nebulae velocities
• Do black hole masses scale with classical bulge luminosities only? The case of the two composite pseudobulge galaxies NGC3368 and NGC3489
• Rings and spirals in barred galaxies. III. Further comparisons and links to observations
• The SAURON Project - XIV. No escape from V${}_{\mathrm{esc}}$: a global and local parameter in early-type galaxy evolution
• How to break the density-anisotropy degeneracy in spherical stellar systems
• Efficient solution of the anisotropic spherically-aligned axisymmetric Jeans equations of stellar hydrodynamics for galactic dynamics
• Peanuts, brezels and bananas: food for thought on the orbital structure of the Galactic bulge
• Discrete dynamical modelling of omega Centauri
• Determination of masses of the central black holes in NGC524 and NGC2549 using Laser Guide Star Adaptive Optics
• Gas dynamics in the Milky Way: a low pattern speed model
• Dark matter scaling relations and the assembly epoch of Coma early-type galaxies
• The mass and angular momentum distribution of simulated massive early-type galaxies to large radii
• Chemodynamical Modelling of the Galactic Bulge and Bar
• Tailoring triaxial N-body models via a novel made-to-measure method
• Elliptical galaxy masses out to five effective radii: the realm of dark matter
• Combining Stellar Populations with Orbit-Superposition Dynamical Modelling - the Formation History of the Lenticular Galaxy NGC 3115
• The Next Generation Virgo cluster Survey. V. modelling the dynamics of M87 with the Made-to-Measure method
• A New Model for the Milky Way Bar
• The EDGE-CALIFA survey: validating stellar dynamical mass models with CO kinematics
• Assessing the Jeans Anisotropic Multi-Gaussian Expansion method with the Illustris simulation
• The stellar mass distribution of the Milky Way's bar: an analytic model
• The Atlas3D project - XII. Recovery of the mass-to-light ratio of simulated early-type barred galaxies with axisymmetric dynamical models
• The Bar and Spiral Arms in the Milky Way: Structure and Kinematics
• A new code for orbit analysis and Schwarzschild modelling of triaxial stellar systems
• Self-consistent models of our Galaxy
• Kinematic deprojection and mass inversion of spherical systems of known velocity anisotropy
• Proper Motion Dispersions of Red Clump Giants in the Galactic Bulge: Observations and Model Comparisons
• Elliptical galaxies with rapidly decreasing velocity dispersion profiles: NMAGIC models and dark halo parameter estimates for NGC 4494
• Kinematic constraints on the stellar and dark matter content of spiral and S0 galaxies
• Sculpting Andromeda -- made-to-measure models for M31's bar and composite bulge: dynamics, stellar and dark matter mass
• Made-to measure galaxy models - I Methodology
• Using NMAGIC to probe the dark matter halo and orbital structure of the X-ray bright, massive elliptical galaxy, NGC 4649
• Made-to-measure galaxy models - III Modelling with Milky Way observations
• Orbital tori for non-axisymmetric galaxies
• Disentangling the formation history of galaxies via population-orbit superposition: method validation
• The Stellar Halo in the Inner Milky Way: Predicted Shape and Kinematics
• The Hercules stream as seen by APOGEE-2 South
• The stellar populations of the central region of M31
• The Initial Mass Function of the Inner Galaxy Measured From OGLE-III Microlensing Timescales
• Constraining the Mass Profiles of Stellar Systems: Schwarzschild Modeling of Discrete Velocity Datasets
• A discrete chemo-dynamical model of the giant elliptical galaxy NGC 5846: dark matter fraction, internal rotation and velocity anisotropy out to six effective radii
• Analysing surveys of our Galaxy I: basic astrometric data
• Applying Schwarzschild's orbit superposition method to barred or non-barred disc galaxies
• A Schwarzschild model of the Galactic bar with initial density from N-body simulations
• Influence of baryons on the orbital structure of dark matter haloes
• Made-to-measure galaxy models - II Elliptical and Lenticular Galaxies
• Three-integral multi-component dynamical models and simulations of the nuclear star cluster in NGC 4244
• Regularizing made-to-measure particle models of galaxies
• Planetary nebulae in the elliptical galaxy NGC 4649 (M 60): kinematics and distance redetermination
• SMART: A new implementation of Schwarzschild's Orbit Superposition technique for triaxial galaxies and its application to an N-body merger simulation
• Disc galaxy modelling with a particle-by-particle M2M method
• Action-based Dynamical Modelling for the Milky Way Disk
• Non-parametric Triaxial Deprojection of Elliptical Galaxies
• M2M modelling of the Galactic disc via PRIMAL: Fitting to Gaia Error Added Data
• Models of Distorted and Evolving Dark Matter Halos
• The Milky Way's middle-aged inner ring
• Made-to-measure modeling of observed galaxy dynamics
• The Fornax3D project: Environmental effects on the assembly of dynamically cold disks in Fornax cluster galaxies
• Investigating Bar Structure of Disc Galaxies via PRIMAL: A PaRtIcle-by-particle M2M ALgorithm
• Theoretical Models of the Galactic Bulge
• Measuring Dark Matter in Galaxies: The Mass Fraction Within 5 Effective Radii
• Mapping the dark matter halo of early-type galaxy NGC 2974 through orbit-based models with combined stellar and cold gas kinematics
• Detailed shapes of the line-of-sight velocity distributions in massive early-type galaxies from non-parametric spectral models
• The bar rotation rate as a diagnostic of dark matter content in the centre of disc galaxies
• Extracting science from surveys of our Galaxy
• Reconstructing the velocity dispersion profiles from the line-of-sight kinematic data in disc galaxies
• Made-to-measure galaxy modelling utilising absorption line strength data
• Unravelling stellar populations in the Andromeda Galaxy
• Rediscovering the Milky Way with orbit superposition approach and APOGEE data I. Method validation
• Basis function expansions for galactic dynamics: Spherical versus cylindrical coordinates
• Quantifying the influence of bars on action-based dynamical modelling of disc galaxies
• Non-equilibrium in the Solar Neighbourhood using dynamical modelling with Gaia DR2
• Made-To-Measure Models of Self-Similar Triaxial Halos with Steep Inner Density Gradients
• Dark matter in massive galaxies
• Self-consistent modelling of our Galaxy with Gaia data
• Dynamical models of the elliptical galaxy NGC 4494
• Nuclear Star Clusters and Bulges
• Total mass distributions of Sersic galaxies from photometry $&$ cent\ ral velocity dispersion
• The fragility of thin discs in galaxies -- I. Building tailored N-body galaxy models
• Anisotropic Models of Dark Halos
• GravSphere2: A higher-order Jeans method for mass-modeling spherical stellar systems
• The effect of kick velocities on the spatial distribution of millisecond pulsars and implications for the Galactic center excess
• The Stellar Kinematics of Extragalactic Bulges
• A method to calculate gravitational accelerations within discrete localised regions in the Milky Way
• Stellar Dynamical Modeling - Accuracy of 3D Density Estimation for Edge-on Axisymmetric Galaxies
• Made-to-Measure Modelling of Globular Clusters
• The validation of made-to-measure method for reconstruction of phase space distribution functions
• The barred inner Milky Way: dynamical models from surveys
• Dynamical Mass Determinations and Scaling Relations of Early-Type Galaxies
• The outer halos of elliptical galaxies
• Self-consistent modelling of the Milky Way's Nuclear Stellar Disc
• Distribution functions for spheroids
• Dynamical properties of high-[Mg/Fe] stars in the Milky Way bar region