Hard X-ray observations of ultraluminous infrared galaxies

Abstract

view Abstract Citations (66) References (27) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Hard X-Ray Observations of Ultraluminous Infrared Galaxies Rieke, G. H. Abstract X-ray flux upper limits of 2-10 keV for ultraluminous infrared galaxies were drawn from the HEAO A-1 data base. The hard X-ray luminosities of these sources are much weaker relative to their total luminosities than would be expected for Seyfert 1 galaxies or quasi-stellar objects. Because of the low level of interstellar extinction for hard X-rays, this result suggests that the ultraluminous galaxies are not powered by embedded QSOs that are otherwise similar to other QSOs. Three other possibilities are (1) the infrared galaxies may contain a form of X-ray-quiet active nucleus, (2) the X-ray sources in active nuclei may not turn on until after the circumnuclear gas has cleared, or (3) the bulk of the infrared luminosity in these galaxies may be generated by intense circumnuclear star formation. Publication: The Astrophysical Journal Pub Date: August 1988 DOI: 10.1086/185224 Bibcode: 1988ApJ...331L...5R Keywords: Active Galactic Nuclei; Infrared Sources (Astronomy); Interstellar Extinction; Seyfert Galaxies; X Ray Sources; Heao 1; Infrared Astronomy Satellite; Star Formation; Stellar Luminosity; Astrophysics; GALAXIES: GENERAL; INFRARED: SOURCES; X-RAYS: SOURCES full text sources ADS | data products SIMBAD (18) NED (12)