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arXiv · 2510.09604

Catalog of Mock Stellar Streams in Milky Way-Like Galaxies

Colin Holm-Hansen·Yingtian Chen·Oleg Y. Gnedin
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Abstract

Dynamically cold stellar streams from tidally dissolved globular clusters (GCs) serve as excellent tools to measure the Galactic mass distribution and show promise to probe the nature of dark matter. For successful application of these tools to observations, it is essential to have models of stellar stream properties on the Galactic scale. To this end we produce a mock catalog of stellar streams in four Milky Way-mass galaxies from cosmological simulations. We build the catalog with three main components: a model for the formation and disruption of globular clusters based on cosmological simulations, time-dependent potentials constructed with basis function expansions for integrating stream orbits, and an improved particle-spray algorithm for efficient generation of stellar streams. We generate mock photometry for Gaia, LSST, and Roman, and find that the latter two surveys will increase the number of observable stars in GC stellar streams by several orders of magnitude, with LSST alone being able to observe 1000 or more stars in 40-100 streams beyond the stellar disk. In addition, we find that the observable widths and lengths of mock streams as a function of galactocentric radius are well described by power-laws with slopes of $-1.8$ and $-2$ for streams beyond 10~kpc. Our full catalog, containing stream populations across four different galaxy realizations, is publicly available and can be used to study stream population statistics and to calibrate models which use stellar streams to understand our Galaxy.

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Colin Holm-Hansen, Yingtian Chen, Oleg Y. Gnedin. 2025-10-10. Catalog of Mock Stellar Streams in Milky Way-Like Galaxies. https://doi.org/10.33232/001c.159598

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