Search for Magnetically Broadened Cascade Emission from Blazars with VERITAS

We present a search for magnetically broadened gamma-ray emission around active galactic nuclei (AGNs), using VERITAS observations of seven hard-spectrum blazars. A cascade process occurs when multi-TeV gamma-rays from an AGN interact with extragalactic background light (EBL) photons to produce elec...

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Detalles Bibliográficos
Publicado: 2017
Materias:
BL Lacertae objects: general
galaxies: active
gamma rays: galaxies
magnetic fields
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v835_n2_p_Archambault
http://hdl.handle.net/20.500.12110/paper_0004637X_v835_n2_p_Archambault
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_0004637X_v835_n2_p_Archambault
record_format dspace
spelling paper:paper_0004637X_v835_n2_p_Archambault2023-06-08T14:29:18Z Search for Magnetically Broadened Cascade Emission from Blazars with VERITAS BL Lacertae objects: general galaxies: active gamma rays: galaxies magnetic fields We present a search for magnetically broadened gamma-ray emission around active galactic nuclei (AGNs), using VERITAS observations of seven hard-spectrum blazars. A cascade process occurs when multi-TeV gamma-rays from an AGN interact with extragalactic background light (EBL) photons to produce electron-positron pairs, which then interact with cosmic microwave background photons via inverse-Compton scattering to produce gamma-rays. Due to the deflection of the electron-positron pairs, a non-zero intergalactic magnetic field (IGMF) would potentially produce detectable effects on the angular distribution of the cascade emission. In particular, an angular broadening compared to the unscattered emission could occur. Through non-detection of angularly broadened emission from 1ES 1218+304, the source with the largest predicted cascade fraction, we exclude a range of IGMF strengths around 10 -14 G at the 95% confidence level. The extent of the exclusion range varies with the assumptions made about the intrinsic spectrum of 1ES 1218+304 and the EBL model used in the simulation of the cascade process. All of the sources are used to set limits on the flux due to extended emission. © 2017. The American Astronomical Society. All rights reserved.. 2017 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v835_n2_p_Archambault http://hdl.handle.net/20.500.12110/paper_0004637X_v835_n2_p_Archambault
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic BL Lacertae objects: general
galaxies: active
gamma rays: galaxies
magnetic fields
spellingShingle BL Lacertae objects: general
galaxies: active
gamma rays: galaxies
magnetic fields
Search for Magnetically Broadened Cascade Emission from Blazars with VERITAS
topic_facet BL Lacertae objects: general
galaxies: active
gamma rays: galaxies
magnetic fields
description We present a search for magnetically broadened gamma-ray emission around active galactic nuclei (AGNs), using VERITAS observations of seven hard-spectrum blazars. A cascade process occurs when multi-TeV gamma-rays from an AGN interact with extragalactic background light (EBL) photons to produce electron-positron pairs, which then interact with cosmic microwave background photons via inverse-Compton scattering to produce gamma-rays. Due to the deflection of the electron-positron pairs, a non-zero intergalactic magnetic field (IGMF) would potentially produce detectable effects on the angular distribution of the cascade emission. In particular, an angular broadening compared to the unscattered emission could occur. Through non-detection of angularly broadened emission from 1ES 1218+304, the source with the largest predicted cascade fraction, we exclude a range of IGMF strengths around 10 -14 G at the 95% confidence level. The extent of the exclusion range varies with the assumptions made about the intrinsic spectrum of 1ES 1218+304 and the EBL model used in the simulation of the cascade process. All of the sources are used to set limits on the flux due to extended emission. © 2017. The American Astronomical Society. All rights reserved..
title Search for Magnetically Broadened Cascade Emission from Blazars with VERITAS
title_short Search for Magnetically Broadened Cascade Emission from Blazars with VERITAS
title_full Search for Magnetically Broadened Cascade Emission from Blazars with VERITAS
title_fullStr Search for Magnetically Broadened Cascade Emission from Blazars with VERITAS
title_full_unstemmed Search for Magnetically Broadened Cascade Emission from Blazars with VERITAS
title_sort search for magnetically broadened cascade emission from blazars with veritas
publishDate 2017
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v835_n2_p_Archambault
http://hdl.handle.net/20.500.12110/paper_0004637X_v835_n2_p_Archambault
_version_ 1768543925223555072

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