Dark Matter reconstruction from stellar orbits in the Galactic Centre

Fuente: arXiv
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Main Authors: Lechien, Thibault, Heißel, Gernot, Grover, Jai, Izzo, Dario
Format: Preprint
Published: 2023
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author Lechien, Thibault
Heißel, Gernot
Grover, Jai
Izzo, Dario
author_facet Lechien, Thibault
Heißel, Gernot
Grover, Jai
Izzo, Dario
contents Context. Current constraints on distributed matter in the innermost Galactic Centre (such as a cluster of faint stars and stellar remnants, Dark Matter or a combination thereof) based on the orbital dynamics of the visible stars closest to the central black hole, typically assume simple functional forms for the distributions. Aims. We take instead a general model agnostic approach in which the form of the distribution is not constrained by prior assumptions on the physical composition of the matter. This approach yields unbiased - entirely observation driven - fits for the matter distribution and places constraints on our ability to discriminate between different density profiles (and consequently between physical compositions) of the distributed matter. Methods. We construct a spherical shell model with the flexibility to fit a wide variety of physically reasonable density profiles by modelling the distribution as a series of concentric mass shells. We test this approach in an analysis of mock observations of the star S2. Results. For a sufficiently large and precise data set, we find that it is possible to discriminate between several physically motivated density profiles. However, for data coming from current and expected next generation observational instruments, the potential for profile distinction will remain limited by the precision of the instruments. Future observations will still be able to constrain the overall enclosed distributed mass within the apocentre of the probing orbit in an unbiased manner. We interpret this in the theoretical context of constraining the secular versus non-secular orbital dynamics.
format Preprint
id arxiv_https___arxiv_org_abs_2308_09170
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Dark Matter reconstruction from stellar orbits in the Galactic Centre
Lechien, Thibault
Heißel, Gernot
Grover, Jai
Izzo, Dario
Astrophysics of Galaxies
General Relativity and Quantum Cosmology
Context. Current constraints on distributed matter in the innermost Galactic Centre (such as a cluster of faint stars and stellar remnants, Dark Matter or a combination thereof) based on the orbital dynamics of the visible stars closest to the central black hole, typically assume simple functional forms for the distributions. Aims. We take instead a general model agnostic approach in which the form of the distribution is not constrained by prior assumptions on the physical composition of the matter. This approach yields unbiased - entirely observation driven - fits for the matter distribution and places constraints on our ability to discriminate between different density profiles (and consequently between physical compositions) of the distributed matter. Methods. We construct a spherical shell model with the flexibility to fit a wide variety of physically reasonable density profiles by modelling the distribution as a series of concentric mass shells. We test this approach in an analysis of mock observations of the star S2. Results. For a sufficiently large and precise data set, we find that it is possible to discriminate between several physically motivated density profiles. However, for data coming from current and expected next generation observational instruments, the potential for profile distinction will remain limited by the precision of the instruments. Future observations will still be able to constrain the overall enclosed distributed mass within the apocentre of the probing orbit in an unbiased manner. We interpret this in the theoretical context of constraining the secular versus non-secular orbital dynamics.
title Dark Matter reconstruction from stellar orbits in the Galactic Centre
topic Astrophysics of Galaxies
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2308.09170