- The paper employs a novel combined likelihood analysis using MAGIC and Fermi-LAT data to constrain dark matter annihilation signals.
- It analyzes gamma-ray emissions from dwarf galaxies across a mass range of 10 GeV to 100 TeV, tightening constraints by up to a factor of two.
- The results reinforce the value of multi-instrument collaborations for indirect dark matter detection and guide future observational strategies.
Limits to Dark Matter Annihilation Cross-Section from Combined MAGIC and Fermi-LAT Observations
This paper discusses a detailed and methodical analysis leveraging data from both the MAGIC Cherenkov telescopes and the Fermi Large Area Telescope (LAT), aimed at detecting signals of dark matter (DM) annihilation. These investigations specifically focus on gamma-ray observations from dwarf satellite galaxies, which are premier candidates due to their high mass-to-light ratios and expected dense dark matter concentrations. The analysis brings forward constraints on the DM annihilation cross-section over an unprecedentedly wide mass range from 10 GeV to 100 TeV.
Methodology
The study integrates over 158 hours of MAGIC telescope observations of the Segue 1 dwarf satellite galaxy with six years of Fermi-LAT observations of 15 dwarf galaxy targets. The joint analysis combines the likelihoods from these individual observations, ensuring a maximized and sensitivity-optimized search procedure for potential gamma-ray signals originating from DM annihilation events.
The emission signal from DM annihilation is characterized by the J-factor, which encapsulates the astrophysical distribution of dark matter in the observed region. The analysis incorporates a thorough modeling of gamma-ray spectral and morphological templates based on the J-factor and considers DM particle masses ranging extensively from GeV to multi-TeV scales.
Results
The results yield stringent upper limits on the annihilation cross-section, improving upon previous MAGIC and Fermi-LAT constraints by up to a factor of two for certain mass values. The data show no significant evidence for DM annihilation signatures, with limits primarily below the thermal relic cross-section for several annihilation channels. This puts additional constraints on theoretical models that predict the nature of DM interactions.
Implications and Future Prospects
Practically, the paper's findings bolster the astrophysical bounds on DM properties, providing valuable input for indirect detection strategies. The result highlights the power of multi-instrument collaborations, combining space-based and ground-based observational data. The technique demonstrated in this research can form the basis for future analyses, potentially including forthcoming gamma-ray and neutrino observatories like CTA and IceCube.
Theoretically, while the absence of a detection does not exclude the presence of DM, more sensitive future observations could constrain the parameter space further. Continued work along these lines might either bring a potential discovery or necessitate the exploration of alternative dark matter models or additional interaction channels beyond weakly interacting massive particles (WIMPs).
Conclusion
The combined analysis of MAGIC and Fermi-LAT data exemplifies a significant step forward in probing the annihilation cross-section of dark matter across an expansive mass spectrum. These efforts demonstrate the crucial role joint experimental strategies play in advancing our understanding of DM properties and further the collective scientific endeavor toward unraveling the fundamental characteristics of this pervasive, elusive substance.