StreamSculptor: Hamiltonian Perturbation Theory for Stellar Streams in Flexible Potentials with Differentiable Simulations

Stellar streams are one of the most promising tracers of low-mass dark-matter subhalos. Existing frameworks for modeling stream perturbations rely on restrictive assumptions for the Milky Way potential (e.g., static, axisymmetric) or are computationally inefficient in generating many realizations of...

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Main Authors: Jacob Nibauer, Ana Bonaca, David N. Spergel, Adrian M. Price-Whelan, Jenny E. Greene, Nathaniel Starkman, Kathryn V. Johnston
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
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Online Access:https://doi.org/10.3847/1538-4357/adb8e8
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author Jacob Nibauer
Ana Bonaca
David N. Spergel
Adrian M. Price-Whelan
Jenny E. Greene
Nathaniel Starkman
Kathryn V. Johnston
author_facet Jacob Nibauer
Ana Bonaca
David N. Spergel
Adrian M. Price-Whelan
Jenny E. Greene
Nathaniel Starkman
Kathryn V. Johnston
author_sort Jacob Nibauer
collection DOAJ
description Stellar streams are one of the most promising tracers of low-mass dark-matter subhalos. Existing frameworks for modeling stream perturbations rely on restrictive assumptions for the Milky Way potential (e.g., static, axisymmetric) or are computationally inefficient in generating many realizations of subhalo impacts. We present StreamSculptor , a GPU accelerated code that combines differentiable simulations and Hamiltonian perturbation theory to model the leading-order effect of dark-matter subhalos on stellar streams. Our model works in two stages: First, a base stream is generated in a Milky Way potential, including the effects of nonlinear time-dependent sources like the rotating Galactic bar and a massive satellite galaxy. Then, linear perturbation theory is applied to the base stream, allowing us to rapidly superimpose the effects of different subhalo impacts without having to carry out additional simulations. Subhalo masses and scale-radii can be rescaled as a postprocessing step. We demonstrate how this framework can be used to model subhalo impacts on stellar streams under realistic Milky Way conditions, specifically for an inner Galaxy stream like Palomar 5 and an outer Galaxy stream like Orphan–Chenab. We find that simultaneously modeling subhalo impacts and other time-dependent components of the Galactic gravitational potential is crucial for an unbiased inference of dark-matter substructure.
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spelling doaj-art-bec7fe47f294416aaaa597de939006132025-08-20T03:09:24ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0198316810.3847/1538-4357/adb8e8StreamSculptor: Hamiltonian Perturbation Theory for Stellar Streams in Flexible Potentials with Differentiable SimulationsJacob Nibauer0https://orcid.org/0000-0001-8042-5794Ana Bonaca1https://orcid.org/0000-0002-7846-9787David N. Spergel2https://orcid.org/0000-0002-5151-0006Adrian M. Price-Whelan3https://orcid.org/0000-0003-0872-7098Jenny E. Greene4https://orcid.org/0000-0002-5612-3427Nathaniel Starkman5https://orcid.org/0000-0003-3954-3291Kathryn V. Johnston6https://orcid.org/0000-0001-6244-6727Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USA ; jnibauer@princeton.eduThe Observatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USADepartment of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USA ; jnibauer@princeton.edu; Center for Computational Astrophysics , Flatiron Institute, 162 5th Avenue, New York, NY 10010, USACenter for Computational Astrophysics , Flatiron Institute, 162 5th Avenue, New York, NY 10010, USADepartment of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USA ; jnibauer@princeton.eduDepartment of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, MA 02139, USADepartment of Astronomy, Columbia University , New York, NY 10027, USAStellar streams are one of the most promising tracers of low-mass dark-matter subhalos. Existing frameworks for modeling stream perturbations rely on restrictive assumptions for the Milky Way potential (e.g., static, axisymmetric) or are computationally inefficient in generating many realizations of subhalo impacts. We present StreamSculptor , a GPU accelerated code that combines differentiable simulations and Hamiltonian perturbation theory to model the leading-order effect of dark-matter subhalos on stellar streams. Our model works in two stages: First, a base stream is generated in a Milky Way potential, including the effects of nonlinear time-dependent sources like the rotating Galactic bar and a massive satellite galaxy. Then, linear perturbation theory is applied to the base stream, allowing us to rapidly superimpose the effects of different subhalo impacts without having to carry out additional simulations. Subhalo masses and scale-radii can be rescaled as a postprocessing step. We demonstrate how this framework can be used to model subhalo impacts on stellar streams under realistic Milky Way conditions, specifically for an inner Galaxy stream like Palomar 5 and an outer Galaxy stream like Orphan–Chenab. We find that simultaneously modeling subhalo impacts and other time-dependent components of the Galactic gravitational potential is crucial for an unbiased inference of dark-matter substructure.https://doi.org/10.3847/1538-4357/adb8e8Stellar streamsDark matterMilky Way Galaxy
spellingShingle Jacob Nibauer
Ana Bonaca
David N. Spergel
Adrian M. Price-Whelan
Jenny E. Greene
Nathaniel Starkman
Kathryn V. Johnston
StreamSculptor: Hamiltonian Perturbation Theory for Stellar Streams in Flexible Potentials with Differentiable Simulations
The Astrophysical Journal
Stellar streams
Dark matter
Milky Way Galaxy
title StreamSculptor: Hamiltonian Perturbation Theory for Stellar Streams in Flexible Potentials with Differentiable Simulations
title_full StreamSculptor: Hamiltonian Perturbation Theory for Stellar Streams in Flexible Potentials with Differentiable Simulations
title_fullStr StreamSculptor: Hamiltonian Perturbation Theory for Stellar Streams in Flexible Potentials with Differentiable Simulations
title_full_unstemmed StreamSculptor: Hamiltonian Perturbation Theory for Stellar Streams in Flexible Potentials with Differentiable Simulations
title_short StreamSculptor: Hamiltonian Perturbation Theory for Stellar Streams in Flexible Potentials with Differentiable Simulations
title_sort streamsculptor hamiltonian perturbation theory for stellar streams in flexible potentials with differentiable simulations
topic Stellar streams
Dark matter
Milky Way Galaxy
url https://doi.org/10.3847/1538-4357/adb8e8
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