Speaker
Description
Cygnus X-3 is a microquasar consisting of a compact object of unknown nature and a Wolf-Rayet star, which orbit each other with a period of 4.8 hours. The compact object launches powerful jets that are an excellent site for particle acceleration up to relativistic energies. The presence of these relativistic particles, combined with the proximity to the star and its high luminosity, create a very favorable scenario for inverse Compton scattering of stellar photons by the jet electrons, resulting in gamma-ray emission. Cygnus X-3 has been detected from radio to gamma rays above 100 MeV, although it has never been confirmed as a very-high-energy (VHE; above 100 GeV) gamma-ray emitter. Studies of microquasars in gamma rays have recently become a hot topic after the LHAASO detection of four microquasars above 100 TeV, establishing these sources as potential contributors to the Galactic cosmic-ray spectrum at energies above the PeV.
The MAGIC telescopes have observed Cygnus X-3 in the VHE band since they became operational. In this contribution, we present a long-term analysis of 130 h collected by MAGIC between 2013 and 2024. This represents the largest available dataset (in both exposure and time coverage) at VHE to date, resulting in the strongest VHE upper limits of the source between 100 GeV and a few TeV. Temporal and spectral constraints of Cygnus X-3 during this period will be interpreted within the multi-wavelength context, providing meaningful constraints on the source properties based on its (lack of) emission in gamma rays at different energies.
| Contribution | Oral talk |
|---|---|
| Affiliation | Instituto de Astrofísica de Canarias |
| luis.barrios@iac.es |
