Comparing Galactic Center MSSM dark matter solutions to the Reticulum II gamma-ray data

TL;DR

This study examines whether specific MSSM dark matter models can explain gamma-ray signals from Reticulum II, aligning with previous Galactic center findings, and assesses the consistency of the required J-factors with observational data.

Contribution

It demonstrates that MSSM dark matter scenarios consistent with the Galactic center excess also explain the Reticulum II gamma-ray excess, linking two astrophysical observations.

Findings

MSSM parameter ranges fit the Reticulum II gamma-ray excess.

The required J-factor is consistent with independent kinematic analyses.

The same MSSM models explain signals from both the Galactic center and Reticulum II.

Abstract

Observations with the Fermi Large Area Telescope (LAT) indicate a possible small photon signal originating from the dwarf galaxy Reticulum II that exceeds the expected background between 2 GeV and 10 GeV. We have investigated two specific scenarios for annihilating WIMP dark matter within the phenomenological Minimal Supersymmetric Standard Model (pMSSM) framework as a possible source for these photons. We find that the same parameter ranges in pMSSM as reported by an earlier paper to be consistent with the Galactic center excess, is also consistent with the excess observed in Reticulum II, resulting in a J-factor of $\log_{10}(J(\alpha_{int}=0.5 deg)) \simeq (20.3-20.5)^{+0.2}_{-0.3}$. This J-factor is consistent with $\log_{10}(J(\alpha_{int}=0.5 deg)) = 19.5^{+1.0}_{-0.6}$ GeV$^2$cm$^{-5}$, which is derived using an optimized spherical Jeans analysis of kinematic data obtained from the Michigan/Magellan Fiber System (M2FS).