Fanaroff-Riley I galaxies as the parent population of BL Lacertae objects. I. X-ray constraints

Journal Article · Fri Jun 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168817· OSTI ID:6692430

Padovani, P; Urry, C M ^[1]

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1. Space Telescope Science Institute, Baltimore, MD (USA)

The hypothesis that BL Lacertae objects are a special subset of Fanaroff-Riley type I radio galaxies, namely, those dominated by beamed emission from a relativistic jet aligned with the line of sight, is examined by looking at the relative number densities. The calculation depends primarily on observed quantities, including the X-ray luminosity function of Fanaroff-Riley type I galaxies. The model predicts the X-ray luminosity function of BL Lacertae objects, the shape of the X-ray counts below currently observed fluxes, and the velocity of the X-ray emitting jet. With Fanaroff-Riley type I galaxies as the parent population the flat luminosity function, the observed X-ray number counts, and the partial redshift distribution of BL Lacertae objects can be explained. 41 refs.

• OSTI ID: 6692430
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 356; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BL LACERTAE OBJECTS
CLASSIFICATION
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
GALAXIES
IONIZING RADIATIONS
LUMINOSITY
MATHEMATICAL MODELS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLASMA JETS
RADIATIONS
RADIO GALAXIES
RED SHIFT
SPECTRA
X RADIATION