Gamma-ray observations of low-luminosity active galactic nuclei

Author(s)

de Menezes, Raniere ^{[1, 2]} ; Nemmen, Rodrigo ^[1] ; Finke, Justin D. ^[3] ; Almeida, Ivan ^[1] ; Rani, Bindu ^{[4, 5, 6, 7]}

Affiliation

^[1] Univ Sao Paulo, Geofis & Ciencias Atmosfer, Inst Astron, Dept Astron, BR-05508090 Sao Paulo, SP - Brazil

^[2] Univ Torino, Dipartimento Fis, Via Pietro Giuria 1, I-10125 Troino - Italy

^[3] US Naval Res Lab, Code 7653, 4555 Overlook Ave SW, Washington, DC 20375 - USA

^[4] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 - USA

^[5] Korea Astron & Space Sci Inst, Daejeon 34055 - South Korea

^[6] Southeastent Univ Res Assoc, Washington, DC 20005 - USA

^[7] NASA, GSFC, Ctr Res & Explorat Space Sci & Technol, Greenbelt, MD 20771 - USA

• Document type: Journal article
• Source: Monthly Notices of the Royal Astronomical Society; v. 492, n. 3, p. 4120-4130, MAR 2020.
• Web of Science Citations: 4

Abstract

The majority of the activity around nearby (z approximate to 0) supermassive black holes is found in low-luminosity active galactic nuclei (LLAGN), the most of them being classified as low ionization nuclear emission regions. Although these sources are well studied from radio up to X-rays, they are poorly understood in gamma-rays. In this work, we take advantage of the all sky-surveying capabilities of the Large Area Telescope on board Fermi Gamma-ray Space Telescope to study the whole Palomar sample of LLAGN in gamma-rays. Precisely, the four radio brightest LLAGN in the sample are identified as significant gamma-ray emitters, all of which are recognized as powerful Fanaroff-Riley 1 galaxies. These results suggest that the presence of powerful radio jets is of substantial importance for observing a significant gamma-ray counterpart even if these jets are misaligned with respect to the line of sight. We also find that most of the X-ray-brightest LLAGN do not have a significant gamma-ray and strong radio emission, suggesting that the X-rays come mainly from the accretion flow in these cases. A detailed analysis of the spectral energy distributions (SEDs) of NGC 315 and NGC 4261, both detected in gamma-rays, is provided where we make a detailed comparison between the predicted hadronic gamma-ray emission from a radiatively inefficient accretion flow (RIAF) and the gamma-ray emission from a leptonic jet-dominated synchrotron self-Compton (SSC) model. Both SEDs are better described by the SSC model, while the RIAF fails to explain the gamma-ray observations. (AU)

• FAPESP's process: 19/10054-7 - Black hole winds and feedback
• Grantee: Ivan Carlos de Almeida
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/01461-2 - The extreme universe: black holes and the Fermi telescope
• Grantee: Rodrigo Nemmen da Silva
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 16/24857-6 - Winds and feedback from supermassive black holes accreting at low rates
• Grantee: Ivan Carlos de Almeida
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 18/24801-6 - Multislit spectroscopy of unidentified gamma-ray sources
• Grantee: Raniere Maciel de Menezes
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate