The Contribution of Fermi-2LAC Blazars to Diffuse TEV-PEV Neutrino Flux
The recent discovery of a diffuse cosmic neutrino flux extending up to PeV energies raises the question of which astrophysical sources generate this signal. Blazars are one class of extragalactic sources which may produce such high-energy neutrinos. We present a likelihood analysis searching for cum...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | en_US |
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Institute of Physics Publishing (IOP)
2017
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| Online Access: | http://hdl.handle.net/1721.1/109483 https://orcid.org/0000-0001-8866-3826 https://orcid.org/0000-0003-1032-6496 https://orcid.org/0000-0002-6393-0438 https://orcid.org/0000-0001-6243-1453 https://orcid.org/0000-0001-7909-5812 |
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| author | IceCube Collaboration Arguelles Delgado, Carlos A Axani, Spencer Nicholas Collin, Gabriel Lewis Conrad, Janet Marie Jones, Benjamin James Poyner Moulai, Marjon H. |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics IceCube Collaboration Arguelles Delgado, Carlos A Axani, Spencer Nicholas Collin, Gabriel Lewis Conrad, Janet Marie Jones, Benjamin James Poyner Moulai, Marjon H. |
| author_sort | IceCube Collaboration |
| collection | MIT |
| description | The recent discovery of a diffuse cosmic neutrino flux extending up to PeV energies raises the question of which astrophysical sources generate this signal. Blazars are one class of extragalactic sources which may produce such high-energy neutrinos. We present a likelihood analysis searching for cumulative neutrino emission from blazars in the 2nd Fermi-LAT AGN catalog (2LAC) using IceCube neutrino data set 2009-12, which was optimized for the detection of individual sources. In contrast to those in previous searches with IceCube, the populations investigated contain up to hundreds of sources, the largest one being the entire blazar sample in the 2LAC catalog. No significant excess is observed, and upper limits for the cumulative flux from these populations are obtained. These constrain the maximum contribution of 2LAC blazars to the observed astrophysical neutrino flux to 27% or less between around 10 TeV and 2 PeV, assuming the equipartition of flavors on Earth and a single power-law spectrum with a spectral index of −2.5. We can still exclude the fact that 2LAC blazars (and their subpopulations) emit more than 50% of the observed neutrinos up to a spectral index as hard as −2.2 in the same energy range. Our result takes into account the fact that the neutrino source count distribution is unknown, and it does not assume strict proportionality of the neutrino flux to the measured 2LAC γ-ray signal for each source. Additionally, we constrain recent models for neutrino emission by blazars. |
| first_indexed | 2024-09-23T09:28:52Z |
| format | Article |
| id | mit-1721.1/109483 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T09:28:52Z |
| publishDate | 2017 |
| publisher | Institute of Physics Publishing (IOP) |
| record_format | dspace |
| spelling | mit-1721.1/1094832022-09-30T14:42:01Z The Contribution of Fermi-2LAC Blazars to Diffuse TEV-PEV Neutrino Flux IceCube Collaboration Arguelles Delgado, Carlos A Axani, Spencer Nicholas Collin, Gabriel Lewis Conrad, Janet Marie Jones, Benjamin James Poyner Moulai, Marjon H. Massachusetts Institute of Technology. Department of Physics Massachusetts Institute of Technology. Laboratory for Nuclear Science Arguelles Delgado, Carlos A Axani, Spencer Nicholas Collin, Gabriel Lewis Conrad, Janet Marie Jones, Benjamin James Poyner Moulai, Marjon H. The recent discovery of a diffuse cosmic neutrino flux extending up to PeV energies raises the question of which astrophysical sources generate this signal. Blazars are one class of extragalactic sources which may produce such high-energy neutrinos. We present a likelihood analysis searching for cumulative neutrino emission from blazars in the 2nd Fermi-LAT AGN catalog (2LAC) using IceCube neutrino data set 2009-12, which was optimized for the detection of individual sources. In contrast to those in previous searches with IceCube, the populations investigated contain up to hundreds of sources, the largest one being the entire blazar sample in the 2LAC catalog. No significant excess is observed, and upper limits for the cumulative flux from these populations are obtained. These constrain the maximum contribution of 2LAC blazars to the observed astrophysical neutrino flux to 27% or less between around 10 TeV and 2 PeV, assuming the equipartition of flavors on Earth and a single power-law spectrum with a spectral index of −2.5. We can still exclude the fact that 2LAC blazars (and their subpopulations) emit more than 50% of the observed neutrinos up to a spectral index as hard as −2.2 in the same energy range. Our result takes into account the fact that the neutrino source count distribution is unknown, and it does not assume strict proportionality of the neutrino flux to the measured 2LAC γ-ray signal for each source. Additionally, we constrain recent models for neutrino emission by blazars. National Science Foundation (U.S.) 2017-05-31T21:01:34Z 2017-05-31T21:01:34Z 2017-01 2016-11 Article http://purl.org/eprint/type/JournalArticle 1538-4357 http://hdl.handle.net/1721.1/109483 Aartsen, M. G., K. Abraham, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, et al. “THE CONTRIBUTION OF FERMI-2LAC BLAZARS TO DIFFUSE TEV–PEV NEUTRINO FLUX.” The Astrophysical Journal 835, no. 1 (January 17, 2017): 45. © Copyright 2017 IOP Publishing. https://orcid.org/0000-0001-8866-3826 https://orcid.org/0000-0003-1032-6496 https://orcid.org/0000-0002-6393-0438 https://orcid.org/0000-0001-6243-1453 https://orcid.org/0000-0001-7909-5812 en_US http://dx.doi.org/10.3847/1538-4357/835/1/45 Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf Institute of Physics Publishing (IOP) IOP Publishing |
| spellingShingle | IceCube Collaboration Arguelles Delgado, Carlos A Axani, Spencer Nicholas Collin, Gabriel Lewis Conrad, Janet Marie Jones, Benjamin James Poyner Moulai, Marjon H. The Contribution of Fermi-2LAC Blazars to Diffuse TEV-PEV Neutrino Flux |
| title | The Contribution of Fermi-2LAC Blazars to Diffuse TEV-PEV Neutrino Flux |
| title_full | The Contribution of Fermi-2LAC Blazars to Diffuse TEV-PEV Neutrino Flux |
| title_fullStr | The Contribution of Fermi-2LAC Blazars to Diffuse TEV-PEV Neutrino Flux |
| title_full_unstemmed | The Contribution of Fermi-2LAC Blazars to Diffuse TEV-PEV Neutrino Flux |
| title_short | The Contribution of Fermi-2LAC Blazars to Diffuse TEV-PEV Neutrino Flux |
| title_sort | contribution of fermi 2lac blazars to diffuse tev pev neutrino flux |
| url | http://hdl.handle.net/1721.1/109483 https://orcid.org/0000-0001-8866-3826 https://orcid.org/0000-0003-1032-6496 https://orcid.org/0000-0002-6393-0438 https://orcid.org/0000-0001-6243-1453 https://orcid.org/0000-0001-7909-5812 |
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