Here, recent claims that the strength BIGMF of the intergalactic magnetic field (IGMF) is ≳10–15 G are based on upper limits to the expected cascade flux in the GeV band produced by blazar TeV photons absorbed by the extragalactic background light. This limit depends on an assumption that the mean blazar TeV flux remains constant on timescales ≳2(B IGMF/10–18G)2/(E/10 GeV)2 yr for an IGMF coherence length ≈1 Mpc, where E is the measured photon energy. Restricting TeV activity of 1ES 0229+200 to ≈3-4 years during which the source has been observed leads to a more robust lower limit of B IGMF ≳10–18 G, which can be larger by an order of magnitude if the intrinsic source flux above ≈5-10 TeV from 1ES 0229+200 is strong.
Dermer, Charles D., et al. "Time delay of cascade radiation for TeV blazars and the measurement of the intergalactic magnetic field." The Astrophysical Journal. Letters, vol. 733, no. 2, May. 2011. https://doi.org/10.1088/2041-8205/733/2/L21
Dermer, Charles D., Cavadini, Massimo, Razzaque, Soebur, Finke, Justin D., Chiang, James, & Lott, Benoit (2011). Time delay of cascade radiation for TeV blazars and the measurement of the intergalactic magnetic field. The Astrophysical Journal. Letters, 733(2). https://doi.org/10.1088/2041-8205/733/2/L21
Dermer, Charles D., Cavadini, Massimo, Razzaque, Soebur, et al., "Time delay of cascade radiation for TeV blazars and the measurement of the intergalactic magnetic field," The Astrophysical Journal. Letters 733, no. 2 (2011), https://doi.org/10.1088/2041-8205/733/2/L21
@article{osti_1357237,
author = {Dermer, Charles D. and Cavadini, Massimo and Razzaque, Soebur and Finke, Justin D. and Chiang, James and Lott, Benoit},
title = {Time delay of cascade radiation for TeV blazars and the measurement of the intergalactic magnetic field},
annote = {Here, recent claims that the strength BIGMF of the intergalactic magnetic field (IGMF) is ≳10–15 G are based on upper limits to the expected cascade flux in the GeV band produced by blazar TeV photons absorbed by the extragalactic background light. This limit depends on an assumption that the mean blazar TeV flux remains constant on timescales ≳2(B IGMF/10–18G)2/(E/10 GeV)2 yr for an IGMF coherence length ≈1 Mpc, where E is the measured photon energy. Restricting TeV activity of 1ES 0229+200 to ≈3-4 years during which the source has been observed leads to a more robust lower limit of B IGMF ≳10–18 G, which can be larger by an order of magnitude if the intrinsic source flux above ≈5-10 TeV from 1ES 0229+200 is strong.},
doi = {10.1088/2041-8205/733/2/L21},
url = {https://www.osti.gov/biblio/1357237},
journal = {The Astrophysical Journal. Letters},
issn = {ISSN 2041-8205},
number = {2},
volume = {733},
place = {United States},
publisher = {Institute of Physics (IOP)},
year = {2011},
month = {05}}
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 551, Issue 2-3https://doi.org/10.1016/j.nima.2005.05.068
HIGH ENERGY GAMMA-RAY ASTRONOMY: 5th International Meeting on High Energy Gamma-Ray Astronomy, AIP Conference Proceedingshttps://doi.org/10.1063/1.4772332