Can observations of 511 keV line from the M31 galaxy shed light on the AGN jet composition?

Abstract

Positron annihilation line at 511~keV is a known component of the gamma-ray diffuse emission. It is believed to be produced in the Galaxy, but there could be possible extragalactic contribution as well. E.g., positrons can be produced in jets of active galactic nuclei (AGN) and after that accumulate and gradually annihilate in hot gaseous halos around galaxies. In this work we test this hypothesis in application to an individual object -- the Andromeda galaxy (M31) which is close and has a supermassive black hole in its center, which powered an AGN before. We compute the growth history of the supermassive black hole in M31, relate it to the evolution of jet luminosity and estimate the positron content in its halo. We calculate the 511~keV photon flux due to positron annihilation which should be observed at Earth and find the value of around $10^{-4}$ photon cm${}^{-2}$s${}^{-1}$. It is very close to the observational limits ($<10^{-4}$photon cm${}^{-2}$s${}^{-1}$) set by the INTEGRAL/SPI in the assumption of the point source, so further observations would be able to constrain leptonic models of the jets and propagation of cosmic rays in the circumgalactic medium of large spiral galaxies.

arXiv comment9 pages, 4 figures. Accepted to Astronomy Letters

References in corpus (30)

• Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
• Local Supermassive Black Holes, Relics of Active Galactic Nuclei and the X-ray Background
• The Circumgalactic Medium
• Cosmological Evolution of the Hard X-ray AGN Luminosity Function and the Origin of the Hard X-ray Background
• Canonical high power blazars
• The power of relativistic jets is larger than the luminosity of their accretion disks
• The 511 keV emission from positron annihilation in the Galaxy
• HST STIS spectroscopy of the triple nucleus of M31: two nested disks in Keplerian rotation around a Supermassive Black Hole
• Science with e-ASTROGAM (A space mission for MeV-GeV gamma-ray astrophysics)
• The Fermi Bubbles: Giant, Multi-Billion-Year-Old Reservoirs of Galactic Center Cosmic Rays
• Stringent Constraint on Galactic Positron Production
• But What About... Cosmic Rays, Magnetic Fields, Conduction, & Viscosity in Galaxy Formation
• Cosmic Rays from Microquasars: a Narrow Component to the CR Spectrum?
• Evidence for a Massive, Extended Circumgalactic Medium Around the Andromeda Galaxy
• Positron annihilation signatures associated with the outburst of the microquasar V404 Cygni
• A RIAF Interpretation for the Past Higher Activity of the Galactic Center Black Hole and the 511 keV Annihilation Emission
• Westerbork HI observations of high-velocity clouds near M31 and M33
• Circum-Galactic Gas and the Isotropic Gamma Ray Background
• The Circum-Galactic Medium of MASsive Spirals II: Probing the Nature of Hot Gaseous Halo around the Most Massive Isolated Spiral Galaxies
• The Supermassive Black Hole at the Heart of Centaurus A: Revealed by Gas- and Stellar Kinematics
• The power and production efficiency of blazar jets
• Constraining the supermassive black holes evolution through the continuity equation
• Electron positron pairs in blazar jets and gamma-ray loud radio-galaxies
• Insight-HXMT, NuSTAR and INTEGRAL Data Show Disk Truncation in the Hard State of the Black-Hole X-Ray Binary MAXI J1820+070
• The Ultimate Fate of Cosmic Rays from Galaxies and their Role in the Intergalactic Medium
• Exploring the hot gaseous halo around an extremely massive and relativistic jet launching spiral galaxy with XMM-Newton
• Discovery of an Halpha emitting disk around the supermassive black hole of M31
• Emission of Positron Annihilation Line Radiation by Clusters of Galaxies
• The Composition and Power of the Jet of the Broad-Line Radio Galaxy 3C 120
• What are the Composition and Power of the Jet in Cyg X-1?