SENSITIVITY OF THE CHERENKOV TELESCOPE ARRAY TO THE DETECTION OF INTERGALACTIC MAGNETIC FIELDS
Number of Authors: 3
2016 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 827, no 2, 147Article in journal (Refereed) Published
Very high energy (VHE; energy E greater than or similar to 100 GeV) gamma-rays originating from extragalactic sources undergo pair production with low-energy photons of background radiation fields. These pairs can inverse-Compton-scatter background photons, initiating an electromagnetic cascade. The spatial and temporal structure of this secondary gamma-ray signal is altered as the e(+)e(-) pairs are deflected in an intergalactic magnetic field (IGMF). We investigate how VHE observations with the future Cherenkov Telescope Array, with its high angular resolution and broad energy range, can potentially probe the IGMF. We identify promising sources and simulate gamma-ray spectra over a wide range of values of the IGMF strength and coherence length using the publicly available ELMAG Monte. Carlo code. Combining simulated observations in a joint likelihood approach, we find that current limits on the IGMF can be significantly improved. The projected sensitivity depends strongly on the time a source has been gamma-ray active and on the emitted maximum gamma-ray energy.
Place, publisher, year, edition, pages
2016. Vol. 827, no 2, 147
astroparticle physics, BL Lacertae objects: general, gamma rays: galaxies, magnetic fields
IdentifiersURN: urn:nbn:se:su:diva-135108DOI: 10.3847/0004-637X/827/2/147ISI: 000384001600059OAI: oai:DiVA.org:su-135108DiVA: diva2:1046636