Shedding light on low-mass subhalo survival and annihilation luminosity with numerical simulations
Entity
UAM. Departamento de Física TeóricaPublisher
Published by Oxford University Press on behalf of Royal Astronomical SocietyDate
2022-10-13Citation
10.1093/mnras/stac2921
Monthly Notices of the Royal Astronomical Society 518.1 (2023): 93-110
ISSN
0035-8711 (print); 1365-2966 (online)DOI
10.1093/mnras/stac2921Project
Gobierno de España. PGC2018-095161-B-I00; Gobierno de España. CEX2020-001007-S; info:eu-repo/grantAgreement/EC/H2020/716151/EU//BACCOEditor's Version
https://doi.org/10.1093/mnras/stac2921Subjects
Galaxies: Haloes; Cosmology: Theory; Cosmology: Dark Matter; Methods: Numerical; FísicaRights
© 2022 The Author(s)Abstract
In this work, we carry out a suite of specially designed numerical simulations to shed light on dark matter (DM) subhalo
survival at mass scales relevant for gamma-ray DM searches, a topic subject to intense debate nowadays. We have employed
an improved version of DASH, a GPU N-body code, to study the evolution of low-mass subhaloes inside a Milky-Way-like
halo with unprecedented accuracy, reaching solar-mass and sub-parsec resolution. We simulate subhaloes with varying mass,
concentration, and orbital properties, and consider the effect of baryons in the host. We analyse the evolution of the bound
mass fraction and annihilation luminosity, finding that most subhaloes survive until present, yet losing in some cases more than
99 per cent of their initial mass. Baryons induce a much greater mass-loss, especially when the subhalo orbit is more parallel
to the Galactic disc. Many of these subhaloes cross the solar Galactocentric radius, making it easier to detect their annihilation
fluxes from Earth. We find subhaloes orbiting a DM-only halo with a pericentre in the solar vicinity to lose 70–90 per cent
of their initial annihilation luminosity at present, which increases up to 99 per cent when including baryons. We find a strong
relation between subhalo’s mass-loss and the effective tidal field at pericentre. Indeed, much of the dependence on all considered
parameters can be explained through this single parameter. In addition to shedding light on the survival of low-mass Galactic
subhaloes, our results can provide detailed predictions that will aid current and future quests for the nature of DM
Files in this item
Google Scholar:Aguirre Santaella, Alejandra
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Sánchez Conde, Miguel Ángel
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Ogiya, Go
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Stucker, Jens
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Angulo, Angulo
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