{"work":{"id":"da6402f0-49a6-4ecd-99d5-85ddecd0b995","openalex_id":null,"doi":null,"arxiv_id":"1410.3696","raw_key":null,"title":"The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV","authors":null,"authors_text":"Fermi-LAT collaboration, The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV, Astrophys","year":2014,"venue":"astro-ph.HE","abstract":"The {\\gamma}-ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, and a residual all-sky emission component commonly called the isotropic diffuse {\\gamma}-ray background (IGRB). The IGRB comprises all extragalactic emissions too faint or too diffuse to be resolved in a given survey, as well as any residual Galactic foregrounds that are approximately isotropic. The first IGRB measurement with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) used 10 months of sky-survey data and considered an energy range between 200 MeV and 100 GeV. Improvements in event selection and characterization of cosmic-ray backgrounds, better understanding of the diffuse Galactic emission, and a longer data accumulation of 50 months, allow for a refinement and extension of the IGRB measurement with the LAT, now covering the energy range from 100 MeV to 820 GeV. The IGRB spectrum shows a significant high-energy cutoff feature, and can be well described over nearly four decades in energy by a power law with exponential cutoff having a spectral index of $2.32\\pm0.02$ and a break energy of $(279\\pm52)$ GeV using our baseline diffuse Galactic emission model. The total intensity attributed to the IGRB is $(7.2\\pm0.6) \\times 10^{-6}$ cm$^{-2}$ s$^{-1}$ sr$^{-1}$ above 100 MeV, with an additional $+15$%/$-30$% systematic uncertainty due to the Galactic diffuse foregrounds.","external_url":"https://arxiv.org/abs/1410.3696","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-05-24T12:34:28.537107+00:00","pith_arxiv_id":"1410.3696","created_at":"2026-05-11T12:21:07.742020+00:00","updated_at":"2026-05-24T12:34:28.537107+00:00","title_quality_ok":true,"display_title":"Kappadath,Measurement of the Cosmic Diffuse Gamma-Ray Spectrum from 800 keV to 30 MeV, PhD dissertation, University of New Hampshire, Fall","render_title":"Kappadath,Measurement of the Cosmic Diffuse Gamma-Ray Spectrum from 800 keV to 30 MeV, PhD dissertation, University of New Hampshire, Fall"},"hub":{"state":{"work_id":"da6402f0-49a6-4ecd-99d5-85ddecd0b995","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":10,"external_cited_by_count":null,"distinct_field_count":3,"first_pith_cited_at":"2020-02-27T05:17:54+00:00","last_pith_cited_at":"2026-05-13T18:00:05+00:00","author_build_status":"not_needed","summary_status":"needed","contexts_status":"needed","graph_status":"needed","ask_index_status":"not_needed","reader_status":"not_needed","recognition_status":"not_needed","updated_at":"2026-05-26T17:46:59.659927+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":4},{"context_role":"baseline","n":2}],"polarity_counts":[{"context_polarity":"background","n":4},{"context_polarity":"baseline","n":2}],"runs":{},"summary":{},"graph":{},"authors":[]}}