X-ray flares in NGC 4151 - A thermal model and constraints on a central black hole

Abstract

view Abstract Citations (64) References (31) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS X-ray flares in NGC 4151: a thermal model and constraints on a central black hole. Lightman, A. P. ; Giacconi, R. ; Tananbaum, H. Abstract Motivated by the recent discovery that the Seyfert galaxy NGC 4151 exhibits rapid X-ray flaring, a thermal model for this source is discussed. Inverse Compton scattering of soft photons gives a predicted relationship for rise time versus energy during X-ray flares. A second prediction, arising from the large optical depth to pair production deduced for the source, is that the power-law spectrum should not extend to energies of approximately 500 keV. If it is assumed that NGC 4151 is powered by accretion onto a black hole, then a black-hole mass of no more than about 4 million solar masses is deduced for the source. Constraints on such black-hole models in general are suggested. Publication: The Astrophysical Journal Pub Date: September 1978 DOI: 10.1086/156384 Bibcode: 1978ApJ...224..375L Keywords: Black Holes (Astronomy); Compton Effect; Galactic Nuclei; Seyfert Galaxies; Thermal Emission; X Ray Sources; Astronomical Models; Energy Bands; Flux Density; Galactic Radiation; Luminous Intensity; Synchrotron Radiation; Astrophysics; Black Holes:Galactic Nuclei; Seyfert Galaxies:Thermal Models; Seyfert Galaxies:X-Ray Flares full text sources ADS | data products NED (1)