Precise estimation of Extragalactic Background Light through GeV-TeV gamma-ray observation for distant blazars

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K17652
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Hiroshima University
• Principal Investigator: Yasuyuki Tanaka 広島大学, 宇宙科学センター, 特任助教 (90633941)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: ガンマ線 / 活動銀河核ジェット / 可視赤外線背景放射

Outline of Final Research Achievements

Extragalactic Background Light (EBL) is known as cosmic optical and infrared background radiation and it is important to understand the origin. We analyzed multi-wavelength data from radio to GeV-TeV gamma-ray band for distant blazars and estimated the intensity of Extragalactic Background Light (EBL). Note that the observed GeV-TeV gamma-ray data are absorbed by annihilation with EBL photons, and hence to derive the intrinsic GeV-TeV spectrum, we need radio, optical, and X-ray data. Our result showed that the inferred EBL level is consistent with previously-obtained theoretical estimation, indicating that no significant contribution from other component such as dark matter is needed to explain the inferred EBL level.

Free Research Field

高エネルギー宇宙物理学