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| Format: | Preprint |
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2025
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| Online Access: | https://arxiv.org/abs/2505.14426 |
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| _version_ | 1866911716985536512 |
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| author | Steffen, P. |
| author_facet | Steffen, P. |
| contents | A galaxy-independent radial scaling of the SPARC rotation-curve data reveals a common structure of dark-matter halos across galaxies. Using all 2693 rotation-curve measurements from the 153 SPARC galaxies, we analyze the data within a unified radial framework rather than fitting parametric halo models to individual systems.
An empirical relation between the observed centripetal acceleration $g_{obs}$ and the baryonic acceleration $g_{bar}$. The residual scatter of this relation is consistent with the observational uncertainties, indicating no detectable intrinsic galaxy-dependent bias.
Motivated by the baryonic acceleration, a scaled radial coordinate $r_{sc}$ is introduced through $r = r_0 r_{sc}$, where $r_0$ is defined by $g_{bar} =2\times 10^{-12} m/s^2$. This transformation removes galaxy-to-galaxy scaling and allows all SPARC measurements to be analyzed within a single radial domain.
In this representation empirical radial distributions are obtained for acceleration, dark-matter mass, density, and circular velocity. The combined data indicate the onset of dark-matter effects at $r_{sc} \approx 0.1$, dark-matter dominance for $r_{sc} \gtrsim 0.2$, a linear growth of dark-matter mass with radius $m_{DM}/M_{bar}$ = $(6.9 \pm 0.2)r_{sc} - (0.23 \pm 0.03)$, and a density profile $ρ\propto r_{sc}^{-2}$, and a nearly constant unified rotation velocity for $r_{sc} > 0.2$. The results suggest that the empirical acceleration relation reflects a common radial dark-matter structure shared by the SPARC galaxies. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2505_14426 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Galaxy-Independent Radial Structure of Dark-Matter Halos Steffen, P. Astrophysics of Galaxies High Energy Physics - Phenomenology A galaxy-independent radial scaling of the SPARC rotation-curve data reveals a common structure of dark-matter halos across galaxies. Using all 2693 rotation-curve measurements from the 153 SPARC galaxies, we analyze the data within a unified radial framework rather than fitting parametric halo models to individual systems. An empirical relation between the observed centripetal acceleration $g_{obs}$ and the baryonic acceleration $g_{bar}$. The residual scatter of this relation is consistent with the observational uncertainties, indicating no detectable intrinsic galaxy-dependent bias. Motivated by the baryonic acceleration, a scaled radial coordinate $r_{sc}$ is introduced through $r = r_0 r_{sc}$, where $r_0$ is defined by $g_{bar} =2\times 10^{-12} m/s^2$. This transformation removes galaxy-to-galaxy scaling and allows all SPARC measurements to be analyzed within a single radial domain. In this representation empirical radial distributions are obtained for acceleration, dark-matter mass, density, and circular velocity. The combined data indicate the onset of dark-matter effects at $r_{sc} \approx 0.1$, dark-matter dominance for $r_{sc} \gtrsim 0.2$, a linear growth of dark-matter mass with radius $m_{DM}/M_{bar}$ = $(6.9 \pm 0.2)r_{sc} - (0.23 \pm 0.03)$, and a density profile $ρ\propto r_{sc}^{-2}$, and a nearly constant unified rotation velocity for $r_{sc} > 0.2$. The results suggest that the empirical acceleration relation reflects a common radial dark-matter structure shared by the SPARC galaxies. |
| title | Galaxy-Independent Radial Structure of Dark-Matter Halos |
| topic | Astrophysics of Galaxies High Energy Physics - Phenomenology |
| url | https://arxiv.org/abs/2505.14426 |