Sensitivity of the cherenkov telescope array to the detection of intergalactic magnetic fields

Journal Article · Sat Aug 20 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/827/2/147· OSTI ID:22868758

Meyer, Manuel; Conrad, Jan ^[1]; Dickinson, Hugh ^[2]

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1. The Oskar Klein Center for CosmoParticle Physics, Department of Physics, Stockholm University, Albanova, SE-10691 Stockholm (Sweden)
2.  Department of Physics and Astronomy, Iowa State University, Ames, IA 50011-3160 (United States)

Very high energy (VHE; energy E ≳ 100 GeV) γ-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 γ-ray signal is altered as the e{sup +}e{sup −} 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 γ-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 γ-ray active and on the emitted maximum γ-ray energy.

• OSTI ID: 22868758
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 827; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BACKGROUND RADIATION
BL LACERTAE OBJECTS
COHERENCE LENGTH
COMPUTERIZED SIMULATION
DETECTION
EMISSION
GALAXIES
GAMMA RADIATION
GEV RANGE 100-1000
MAGNETIC FIELDS
PAIR PRODUCTION
RELICT RADIATION
RESOLUTION
SENSITIVITY
SPECTRA
TELESCOPES