An excess of excesses examined via dark matter radio emissions from galaxies. (arXiv:1905.05599v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Beck_G/0/1/0/all/0/1">Geoff Beck</a>
Cosmic-ray and gamma-ray observations have yielded several notable excesses
that often lend themselves to explanation by various dark matter
annihilation/decay models. In particular, the AMS2 anti-proton and positron
excesses have continued to grow with collection of more data. This is
supplemented by gamma-ray excesses in the Galactic Centre and a high-energy
break in spectrum of electron/positron cosmic rays seen by DAMPE. In this work
we carefully model the magnetic field environments of M31 and M33 and use this
to estimate expected synchrotron emissions from electrons produced via dark
matter annihilation. By comparing this to available radio data we review
simplifying assumptions used previously for dark matter hunting in these
environments and produce novel constraints that are capable of fully ruling out
dark matter models proposed to accommodate all the aforementioned excesses
barring that of DAMPE. However, we do show that significant constraints can be
placed upon the DAMPE parameter space with M33 and M31 data. In addition to
this we project SKA non-observation constraints for the Reticulum II and
Triangulum II dwarf galaxies and find these have potential to rule out
cosmic-ray and gamma-ray excess-producing models of dark matter, even when the
most conservative assumptions are employed.
Cosmic-ray and gamma-ray observations have yielded several notable excesses
that often lend themselves to explanation by various dark matter
annihilation/decay models. In particular, the AMS2 anti-proton and positron
excesses have continued to grow with collection of more data. This is
supplemented by gamma-ray excesses in the Galactic Centre and a high-energy
break in spectrum of electron/positron cosmic rays seen by DAMPE. In this work
we carefully model the magnetic field environments of M31 and M33 and use this
to estimate expected synchrotron emissions from electrons produced via dark
matter annihilation. By comparing this to available radio data we review
simplifying assumptions used previously for dark matter hunting in these
environments and produce novel constraints that are capable of fully ruling out
dark matter models proposed to accommodate all the aforementioned excesses
barring that of DAMPE. However, we do show that significant constraints can be
placed upon the DAMPE parameter space with M33 and M31 data. In addition to
this we project SKA non-observation constraints for the Reticulum II and
Triangulum II dwarf galaxies and find these have potential to rule out
cosmic-ray and gamma-ray excess-producing models of dark matter, even when the
most conservative assumptions are employed.
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