Dynamical Evidence of a Solitonic Core of $10^{9}M_\odot$ in the Milky Way

Ivan De Martino; Tom Broadhurst; S. -H. Henry Tye; Tzihong Chiueh; Hsi-Yu Schive

doi:10.1016/j.dark.2020.100503

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arXiv · 1807.08153

Dynamical Evidence of a Solitonic Core of $10^{9}M_\odot$ in the Milky Way

Ivan De Martino·Tom Broadhurst·S. -H. Henry Tye·Tzihong Chiueh·Hsi-Yu Schive

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Abstract

A wavelike solution for the non-relativistic universal dark matter (wave-DM) is rapidly gaining interest, following distinctive predictions of pioneering simulations of cosmic structure as an interference pattern of coherently oscillating bosons. A prominent solitonic standing wave is predicted at the center of every galaxy, representing the ground state, that has been identified with the wide, kpc scale dark cores of common dwarf-spheroidal galaxies, providing a boson mass of, $\simeq 10^{-22}$ eV. A denser soliton is predicted for Milky Way sized galaxies where momentum is higher, so the de Broglie scale of the soliton is smaller, $\simeq 100$ pc, of mass $\simeq 10^9 M_\odot$. Here we show the central motion of bulge stars in the Milky Way implies the presence of such a dark core, where the velocity dispersion rises inversely with radius to a maximum of $\simeq 130$ km/s, corresponding to an excess central mass of $\simeq 1.5\times 10^9 M_\odot$ within $\simeq 100$ pc, favouring a boson mass of $\simeq 10^{-22}$ eV. This quantitative agreement with such a unique and distinctive prediction is therefore strong evidence for a light bosonic solution to the long standing Dark Matter puzzle, such as the axions generic in String Theory.

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Ivan De Martino, Tom Broadhurst, S. -H. Henry Tye, Tzihong Chiueh, Hsi-Yu Schive. 2018-07-21. Dynamical Evidence of a Solitonic Core of $10^{9}M_\odot$ in the Milky Way. https://doi.org/10.1016/j.dark.2020.100503

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