Parity-odd correlators of diffuse gamma rays and intergalactic magnetic fields

• Published in: arXiv.org
• Main Authors: Tashiro, Hiroyuki, Vachaspati, Tanmay
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 12.09.2014
• Subjects: Amplitudes; Correlators; Field strength; Gamma rays; Magnetic fields; Parity; Physics - Cosmology and Nongalactic Astrophysics; Physics - High Energy Astrophysical Phenomena; Physics - High Energy Physics - Phenomenology; Physics - High Energy Physics - Theory; Power spectra
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1409.3627

We develop the connection between intergalactic helical magnetic fields and parity odd signatures in the diffuse gamma ray sky. We find that the location and the amplitude of a peak in a parity odd correlator, \(Q(R)\), can be used to infer the normal and helical power spectra of the intergalactic magnetic field. When applied to Fermi-LAT data, the amplitude of the observed peak in \(Q(R)\) gives \(\sim 10^{-14}~{\rm G}\) intergalactic magnetic field strength, which is consistent with an earlier independent estimate that only used the peak location (Tashiro et al. 2014). We discuss features in the observed \(Q(R)\) that further support the intergalactic magnetic field hypothesis and make predictions for future tests.