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Title: LOWER BOUNDS ON INTERGALACTIC MAGNETIC FIELDS FROM SIMULTANEOUSLY OBSERVED GeV-TeV LIGHT CURVES OF THE BLAZAR Mrk 501

Abstract

We derive lower bounds on intergalactic magnetic fields (IGMFs) from upper limits on the pair echo emission from the blazar Mrk 501, that is, delayed GeV emission from secondary e{sup -}e{sup +} pairs produced via interactions of primary TeV gamma rays with the cosmic infrared background. Utilizing only simultaneous GeV-TeV light curves observed by VERITAS, MAGIC, and the Fermi Large Area Telescope during a multiwavelength campaign in 2009 that included a TeV flare, bounds are deduced on the IGMF strength of B {approx}> 10{sup -20} G at the 90% confidence level for a field coherence length of 1 kpc. Since our analysis is based firmly on the observational data alone and is nearly free of assumptions concerning the primary TeV flux in unobserved periods or spectral bands, our evaluation of the pair echo flux is conservative and the evidence for a non-zero IGMF is more robust compared to previous studies.

Authors:
 [1];  [2];  [3];  [4]
  1. Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan)
  2. Department of Physical Sciences, Ritsumeikan University, 1-1-1 Noji Higashi, Kusatsu, Shiga 525-8577 (Japan)
  3. Department of Physics and Astrophysics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
  4. Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwa-no-Ha, Kashiwa, Chiba 277-8582 (Japan)
Publication Date:
OSTI Identifier:
22047253
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 744; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; BL LACERTAE OBJECTS; COHERENCE LENGTH; COSMIC PHOTONS; DIAGRAMS; EVALUATION; GALAXIES; GAMMA RADIATION; GEV RANGE; INTERGALACTIC SPACE; PAIR PRODUCTION; QUASARS; RELICT RADIATION; TELESCOPES; TEV RANGE; VISIBLE RADIATION

Citation Formats

Takahashi, Keitaro, Mori, Masaki, Ichiki, Kiyotomo, and Inoue, Susumu. LOWER BOUNDS ON INTERGALACTIC MAGNETIC FIELDS FROM SIMULTANEOUSLY OBSERVED GeV-TeV LIGHT CURVES OF THE BLAZAR Mrk 501. United States: N. p., 2012. Web. doi:10.1088/2041-8205/744/1/L7.
Takahashi, Keitaro, Mori, Masaki, Ichiki, Kiyotomo, & Inoue, Susumu. LOWER BOUNDS ON INTERGALACTIC MAGNETIC FIELDS FROM SIMULTANEOUSLY OBSERVED GeV-TeV LIGHT CURVES OF THE BLAZAR Mrk 501. United States. https://doi.org/10.1088/2041-8205/744/1/L7
Takahashi, Keitaro, Mori, Masaki, Ichiki, Kiyotomo, and Inoue, Susumu. 2012. "LOWER BOUNDS ON INTERGALACTIC MAGNETIC FIELDS FROM SIMULTANEOUSLY OBSERVED GeV-TeV LIGHT CURVES OF THE BLAZAR Mrk 501". United States. https://doi.org/10.1088/2041-8205/744/1/L7.
@article{osti_22047253,
title = {LOWER BOUNDS ON INTERGALACTIC MAGNETIC FIELDS FROM SIMULTANEOUSLY OBSERVED GeV-TeV LIGHT CURVES OF THE BLAZAR Mrk 501},
author = {Takahashi, Keitaro and Mori, Masaki and Ichiki, Kiyotomo and Inoue, Susumu},
abstractNote = {We derive lower bounds on intergalactic magnetic fields (IGMFs) from upper limits on the pair echo emission from the blazar Mrk 501, that is, delayed GeV emission from secondary e{sup -}e{sup +} pairs produced via interactions of primary TeV gamma rays with the cosmic infrared background. Utilizing only simultaneous GeV-TeV light curves observed by VERITAS, MAGIC, and the Fermi Large Area Telescope during a multiwavelength campaign in 2009 that included a TeV flare, bounds are deduced on the IGMF strength of B {approx}> 10{sup -20} G at the 90% confidence level for a field coherence length of 1 kpc. Since our analysis is based firmly on the observational data alone and is nearly free of assumptions concerning the primary TeV flux in unobserved periods or spectral bands, our evaluation of the pair echo flux is conservative and the evidence for a non-zero IGMF is more robust compared to previous studies.},
doi = {10.1088/2041-8205/744/1/L7},
url = {https://www.osti.gov/biblio/22047253}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 744,
place = {United States},
year = {Sun Jan 15 00:00:00 EST 2012},
month = {Sun Jan 15 00:00:00 EST 2012}
}