Supermassive black holes and their surroundings: MeV signatures

Abstract

The gravitational potential of supermassive black holes is so powerful that it triggers some of the most intense phenomena in the Universe. Accretion onto these objects and relativistic jet emission from their vicinity are observable across a wide range of frequencies and throughout cosmic history. However, despite this wealth of data, many aspects of their underlying mechanisms remain elusive. Investigating this phenomena across all frequencies is crucial, yet some energy windows are still poorly explored. One such window is the MeV energy range: many key signatures related to the emission from the SMBH environment - both in quiescent and active phases - are expected to lie between one and several hundreds MeV. In this work, we explore some of the open questions regarding the behavior and emission processes in the surroundings of SMBHs, and how these questions might be approached. From the elusive nature of Fermi bubbles around our Galactic Centre, to the origin of high-energy neutrinos in the nuclei and jets of Active Galactic Nuclei, to the nature and emission mechanisms of the most powerful blazars, the MeV window stands out as a crucial key to understanding SMBH physics.

The article is a chapter in the International Space Science Institute (ISSI) book "Unveiling the MeV Universe in Multi-Messenger Era"

References in corpus (36)

• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era
• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• Evidence for neutrino emission from the nearby active galaxy NGC 1068
• The power of relativistic jets is larger than the luminosity of their accretion disks
• The Spectrum and Morphology of the Fermi Bubbles
• All-sky search for time-integrated neutrino emission from astrophysical sources with 7 years of IceCube data
• Swift BAT Survey of AGN
• The Fermi Bubbles: Giant, Multi-Billion-Year-Old Reservoirs of Galactic Center Cosmic Rays
• Detection of large-scale X-ray bubbles in the Milky Way halo
• A Survey of Kiloparsec-Scale Radio Outflows in Radio-Quiet Active Galactic Nuclei
• Spatial distribution of interstellar gas in the innermost 3 kpc of our Galaxy
• High-Energy Gamma Rays from the Milky Way: Three-Dimensional Spatial Models for the Cosmic-Ray and Radiation Field Densities in the Interstellar Medium
• The All-sky Medium Energy Gamma-ray Observatory eXplorer (AMEGO-X) Mission Concept
• The first blazar observed at z>6
• Nuclear Outflow of the Milky Way: Studying the Kinematics and Spatial Extent of the Northern Fermi Bubble
• Particle acceleration in astrophysical jets
• Beginning a journey across the universe: the discovery of extragalactic neutrino factories
• AMEGO: Exploring the Extreme Multimessenger Universe
• Blazar candidates beyond redshift 4 observed by Swift
• NuSTAR Survey of Obscured Swift/BAT-selected Active Galactic Nuclei: II. Median High-energy Cutoff in Seyfert II Hard X-ray Spectra
• The Cosmic MeV Gamma-ray Background and Hard X-ray Spectra of Active Galactic Nuclei: Implications for the Origin of Hot AGN Coronae
• The properties of the AGN torus as revealed from a set of unbiased NuSTAR observations
• Constraining the quasar radio-loud fraction at $z\sim 6$ with deep radio observations
• Disentangling the Hadronic Components in NGC 1068
• The space density of z>4 blazars
• Clues to the origin of Fermi Bubbles from OVIII/OVII line ratio
• Magnetization of jets in luminous blazars
• Nustar Measurement Of Coronal Temperature In Two Luminous, High Redshift Qsos
• BASS XXXIII: Swift-BAT blazars and their jets through cosmic time
• Blazar nature of high-z radio-loud quasars
• VLBI observations of four radio quasars at $z>4$: blazars or not?
• Big and young supermassive black holes in the early Universe
• Misaligned jets from Sgr A${}^{\ast }$ and the origin of Fermi/eROSITA bubbles
• The Composition and Power of the Jet of the Broad-Line Radio Galaxy 3C 120
• $Fermi$-LAT follow-up observations in seven years of real-time high-energy neutrino alerts

Cited by in corpus (1)

• Black-hole mass estimation through accretion disk spectral fitting for high-redshift blazars