Velocity-dependent J-factors for Milky Way dwarf spheroidal analogues in cosmological simulations
| Autor: | Keagan Blanchette, Erin Piccirillo, Nassim Bozorgnia, Louis E. Strigari, Azadeh Fattahi, Carlos S. Frenk, Julio F. Navarro, Till Sawala |
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| Přispěvatelé: | Department of Physics, Faculty of Science |
| Rok vydání: | 2023 |
| Předmět: |
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Hydrodynamical simulations FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 115 Astronomy Space science Astrophysics - Astrophysics of Galaxies High Energy Physics - Phenomenology High Energy Physics - Phenomenology (hep-ph) Dark matter simulations Astrophysics of Galaxies (astro-ph.GA) Dark energy theory Dwarfs galaxies Astrophysics::Galaxy Astrophysics Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Journal of Cosmology and Astroparticle Physics, 2023, Vol.2023(03), pp.021 [Peer Reviewed Journal] |
| Popis: | We study the impact of the dark matter velocity distribution modelling on signals from velocity-dependent dark matter annihilation in Milky Way dwarf spheroidal galaxies. Using the high resolution APOSTLE simulations, we identify analogues corresponding to Milky Way dwarf spheroidal galaxies, and from these directly determine the dark matter pair-wise relative velocity distribution, and compare to best-fitting Maxwell-Boltzmann distribution models. For three velocity-dependent annihilation models, p-wave, d-wave, and the Sommerfeld model, we quantify the errors introduced when using the Maxwell-Boltzmann parameterization. We extract a simple power-law relation between the maximum circular velocity of the dwarf spheroidal analogue and the peak speed of the Maxwell-Boltzmann distribution. We show that this relation can be used to accurately calculate the dark matter relative velocity distribution, and find that it allows us to estimate the dark matter annihilation signal without the need to directly calculate the relative velocity distribution for each galaxy. The scatter in the J-factors calculated from the analogues dominates the uncertainty obtained when compared to the J-factor as determined from the observational data for each dwarf spheroidal, with the largest scatter from d-wave models and the smallest from Sommerfeld models. 17 pages, 7 figures, 2 tables |
| Databáze: | OpenAIRE |
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