TIME DELAY OF CASCADE RADIATION FOR TeV BLAZARS AND THE MEASUREMENT OF THE INTERGALACTIC MAGNETIC FIELD

By C. Dermer, M. Cavadini, S. Razzaque, J. Finke, J. Chiang, B. Lott. 2010

226 citations recorded by the source corpus.

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(BIGMF/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 BIGMF ≳ 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.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/38d43147ba16917187818ae0e39cdd301c8aaea3

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In Nuclear and High Energy Physics

1. Andrii Y. Neronov
2. R. Durrer
3. J. Biteau
4. E. Orlando
5. C. Dermer
6. Kohta Murase
7. Anna Franckowiak
8. J. Finke

Citations in the corpus

• A hadronic origin for ultra-high-frequency-peaked BL Lac objects (2014, background): “This discrepancy may by due to the known variability of the source at GeV energies6 The GeV emission from 1ES 0229+200 was first studied by Dermer et al. (2011), who analyzed LAT data from August 2008 to September 2010 without detecting the source.”
• THE COSMOLOGICAL IMPACT OF LUMINOUS TeV BLAZARS. I. IMPLICATIONS OF PLASMA INSTABILITIES FOR THE INTERGALACTIC MAGNETIC FIELD AND EXTRAGALACTIC GAMMA-RAY BACKGROUND (2011, methodology): “The variability timescale within the TeV source is long in comparison to the geometric time delays between the original TeV and inverse-Compton produced GeV gamma rays due to the orbit of the pairs through some angleϑ, ∆t ∼ 106 (Dpp/80Mpc)(ϑ/0.1rad)2yr (see Dermer et al. 2011).”
• The Search for Spatial Extension in High-latitude Sources Detected by the Fermi Large Area Telescope (2018, background): “Interestingly, some authors found evidence for extended emission around AGNs in analyses of Fermi-LAT data (Chen et al. 2015a; Kotelnikov et al. 2015), while others did not detect any significant extension with combined Fermi-LAT and H.E.S.S. observations(Abramowski et al. 2014), VERITAS observation”
• EGMF Constraints from Simultaneous GeV-TeV Observations of Blazars (2011, methodology): “Relying on this statement, wein- clude 1ES 0229+200 in our analysis, to verify the results ob- tained by Dermer et al. (2010).”
• Cosmological Magnetic Fields: Their Generation, Evolution and Observation (2013, methodology): “The limit of Dermer et al (2011) is lower than that of Taylor et al (2011) because of the difference in the modeling of the cascade signal.”
• Planck 2015 results: XIX. Constraints on primordial magnetic fields (2015, unknown): “Constraints on the GeV emission provide lower limits on the amplitude of intergalactic fields of the order of 10−18–10−15 G (Tavecchio et al. 2010; Taylor et al. 2011; Dermer et al. 2011; Vovk et al. 2012), if this scenario is correct.”
• BLAZARS AS ULTRA-HIGH-ENERGY COSMIC-RAY SOURCES: IMPLICATIONS FOR TeV GAMMA-RAY OBSERVATIONS (2011, background): “Based on the lower limits of BIGVλ 1/2 coh & 10 −18 − 10−17 G Mpc1/2 (Dolag et al. 2011; Dermer et al. 2011; Takahashi et al. 2012) obtained for 1ES 0229+200 (where the termλcoh is the coherence length of the magnetic field, and this relation is understood to apply whenλcoh is smaller than the…”