TY - JOUR
T1 - New constraints on the mass of fermionic dark matter from dwarf spheroidal galaxies
AU - Alvey, James
AU - Sabti, Nashwan
AU - Tiki, Victoria
AU - Blas, Diego
AU - Bondarenko, Kyrylo
AU - Boyarsky, Alexey
AU - Escudero, Miguel
AU - Fairbairn, Malcolm
AU - Orkney, Matthew
AU - Read, Justin I.
N1 - Publisher Copyright:
© 2020 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/2/1
Y1 - 2021/2/1
N2 - Dwarf spheroidal galaxies are excellent systems to probe the nature of fermionic dark matter due to their high observed dark matter phase-space density. In this work, we review, revise, and improve upon previous phase-space considerations to obtain lower bounds on the mass of fermionic dark matter particles. The refinement in the results compared to previous works is realized particularly due to a significantly improved Jeans analysis of the galaxies. We discuss two methods to obtain phase-space bounds on the dark matter mass, one model-independent bound based on Pauli's principle, and the other derived from an application of Liouville's theorem. As benchmark examples for the latter case, we derive constraints for thermally decoupled particles and (non-)resonantly produced sterile neutrinos. Using the Pauli principle, we report a model-independent lower bound of $m \ge 0.18\, \mathrm{keV}$ at 68 per cent CL and $m \ge 0.13\, \mathrm{keV}$ at 95 per cent CL. For relativistically decoupled thermal relics, this bound is strengthened to $m \ge 0.59\, \mathrm{keV}$ at 68 per cent CL and $m \ge 0.41\, \mathrm{keV}$ at 95 per cent CL, while for non-resonantly produced sterile neutrinos the constraint is $m \ge 2.80\, \mathrm{keV}$ at 68 per cent CL and $m \ge 1.74\, \mathrm{keV}$ at 95 per cent CL. Finally, the phase-space bounds on resonantly produced sterile neutrinos are compared with complementary limits from X-ray, Lyman α, and big bang nucleosynthesis observations.
AB - Dwarf spheroidal galaxies are excellent systems to probe the nature of fermionic dark matter due to their high observed dark matter phase-space density. In this work, we review, revise, and improve upon previous phase-space considerations to obtain lower bounds on the mass of fermionic dark matter particles. The refinement in the results compared to previous works is realized particularly due to a significantly improved Jeans analysis of the galaxies. We discuss two methods to obtain phase-space bounds on the dark matter mass, one model-independent bound based on Pauli's principle, and the other derived from an application of Liouville's theorem. As benchmark examples for the latter case, we derive constraints for thermally decoupled particles and (non-)resonantly produced sterile neutrinos. Using the Pauli principle, we report a model-independent lower bound of $m \ge 0.18\, \mathrm{keV}$ at 68 per cent CL and $m \ge 0.13\, \mathrm{keV}$ at 95 per cent CL. For relativistically decoupled thermal relics, this bound is strengthened to $m \ge 0.59\, \mathrm{keV}$ at 68 per cent CL and $m \ge 0.41\, \mathrm{keV}$ at 95 per cent CL, while for non-resonantly produced sterile neutrinos the constraint is $m \ge 2.80\, \mathrm{keV}$ at 68 per cent CL and $m \ge 1.74\, \mathrm{keV}$ at 95 per cent CL. Finally, the phase-space bounds on resonantly produced sterile neutrinos are compared with complementary limits from X-ray, Lyman α, and big bang nucleosynthesis observations.
KW - dark matter
KW - galaxies: dwarf
UR - http://www.scopus.com/inward/record.url?scp=85100342583&partnerID=8YFLogxK
U2 - 10.1093/mnras/staa3640
DO - 10.1093/mnras/staa3640
M3 - Article
AN - SCOPUS:85100342583
SN - 0035-8711
VL - 501
SP - 1188
EP - 1201
JO - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
JF - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
IS - 1
ER -