Systematic biases on galaxy haloes parameters from Yukawa-like gravitational potentials

Abstract

A viable alternative to the dark energy as a solution of the cosmic speed up problem is represented by Extended Theories of Gravity. Should this be indeed the case, there will be an impact not only on cosmological scales, but also at any scale, from the Solar System to extragalactic ones. In particular, the gravitational potential can be different from the Newtonian one commonly adopted when computing the circular velocity fitted to spiral galaxies rotation curves. Phenomenologically modelling the modified point mass potential as the sum of a Newtonian and a Yukawa like correction, we simulate observed rotation curves for a spiral galaxy described as the sum of an exponential disc and a NFW dark matter halo. We then fit these curves assuming parameterized halo models (either with an inner cusp or a core) and using the Newtonian potential to estimate the theoretical rotation curve. Such a study allows us to investigate the bias on the disc and halo model parameters induced by the systematic error induced by forcing the gravity theory to be Newtonian when it is not. As a general result, we find that both the halo scale length and virial mass are significantly overestimated, while the dark matter mass fraction within the disc optical radius is typically underestimated. Moreover, should the Yukawa scale length be smaller than the disc half mass radius, then the logarithmic slope of the halo density profile would turn out to be shallower than the NFW one. Finally, cored models are able to fit quite well the simulated rotation curves, provided the disc mass is biased high in agreement with the results in literature, favoring cored haloes and maximal discs. Such results make us argue that the cusp/core controversy could actually be the outcome of an incorrect assumption about which theory of gravity must actually be used in computing the theoretical circular velocity.

14 pages, 4 figures, 5 tables, accepted for publication on Monthly Notices of Royal Astronomical Society

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Cited by in corpus (28)

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• Galaxy rotation curves in $f(R,\varphi )$-gravity
• Testing Yukawa-like potentials from f(R)-gravity in elliptical galaxies
• Probing hybrid modified gravity by stellar motion around Galactic Centre
• Constraining the range of Yukawa gravity interaction from S2 star orbits III: improvement expectations for graviton mass bounds
• Constraining Extended Gravity Models by S2 star orbits around the Galactic Centre
• Constraining f(R) gravity with PLANCK data on galaxy cluster profiles
• Galaxy rotation curves in modified gravity models
• Estimating the Parameters of Extended Gravity Theories with the Schwarzschild Precession of S2 Star
• The black hole at the Galactic Center: observations and models
• Constraints on Yukawa gravity parameters from observations of bright stars
• A $f(R)$-gravity model of the Sunyaev-Zeldovich profile of the Coma cluster compatible with {\it Planck} data
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• Weak lensing peak count as a probe of f(R) theories
• Prospects for Constraining the Yukawa Gravity with Pulsars around Sagittarius A*
• Influence of bulk mass distribution on orbital precession of S2 star in Yukawa gravity
• Tracking the Local Group Dynamics by Extended Gravity
• Testing gravity with the Milky Way: Yukawa potential
• Addressing the Hubble tension in Yukawa cosmology?
• Probing Short Gravity using Temporal Lensing
• Probing $f(R)$ gravity with PLANCK data on cluster pressure profiles
• Limiting the Yukawa Gravity through the Black Hole Shadows of Sgr A* and M87*
• Constraints on a fifth force from the stellar orbits around the central supermassive black hole of the Milky Way
• A Criterion for Physically Acceptable Extra Dimensions with Boundaries