Gammay rays from Penrose powered black holes in centaurus A, 3C 273, and NGC 4151

Journal Article · Fri Feb 15 04:00:00 EST 1980 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/157723· OSTI ID:5392411

Kafatos, M

Gamma-ray observations of active galaxies have important consequences for theories of the activity in their nuclei. The observations of Cen A, 3C 273, and NGC 4151 are examined under the assumption that Penrose collision processes in the ergospheres of massive black holes power their nuclei. The observed sharp break in the MeV region of the NGC 4151 spectrum cannot be due to the ..gamma..-..gamma.. pair production process. We attribute this break to the Penrose Compton scattering (PCS), in which ..gamma..-rays escape from the ergosphere as a result of Penrose processes involving electrons and lower energy X-ray photons in the ergosphere of the black hole. The absence of an MeV break in the spectra of Cen A and 3C 273 argues in favor of the Penrose pair production (PPP), in which high-energy pairs (a few GeV in energy) escape as result of Penrose processes involving protons and ..gamma..-rays that are present in any hot, optically thin, vertically extended accretion disk. An intrinsic break in the GeV region is predicted for both Cen A and 3C 273 as well as any other PPP powered nucleus.If PPP is important for QSOs and radio galaxies and some Seyferts, powerful radio objects should also be powerful ..gamma..-ray objects. Nuclei in which the black hole is spinning slowly would still emit visible light, UV, and X-rays as result of accretion without Penrose processes but would be weak in radio or high-energy ..gamma..-rays. Future ..gamma..-ray observations should provide clues as to whether this scenario is correct. Besides spectral information at ..gamma..-ray frequencies, possible variability at ..gamma..-ray frequencies should be searched for.

• Research Organization: Department of Physics, George Mason University; and Laboratory for Astronomy and Solar Physics, NASA Goddard Space Flight Center
• OSTI ID: 5392411
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 236:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
640105 -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BASIC INTERACTIONS
BLACK HOLES
COMPTON EFFECT
COSMIC GAMMA SOURCES
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
ELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
GALAXIES
GALAXY NUCLEI
GAMMA RADIATION
GAMMA SPECTRA
INTERACTIONS
IONIZING RADIATIONS
MASSLESS PARTICLES
PAIR PRODUCTION
PHOTONS
QUASARS
RADIATIONS
RADIO GALAXIES
SCATTERING
SEYFERT GALAXIES
SPECTRA
STAR ACCRETION
STAR EVOLUTION
TWISTOR THEORY
X-RAY SPECTRA