Reverberation mapping of the emission line regions of Seyfert galaxies and quasars

Journal Article · Thu Apr 15 04:00:00 EST 1982 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/159843· OSTI ID:5080299

Blandford, R D; McKee, C F

Variations in the strengths of the central photoionization source in a quasar or Seyfert galaxy will generate variations in the strengths and profiles of the emission lines. These ''reverberations'' in the emission lines will lag behind the continuum variations due to light travel time effects. A procedure is described for analyzing a time series of measurements of both the continuum and the lines. This procedure permits direct verification of the assumed causal connection of the lines to the continuum. We demonstrate that if the emission line region has a high degree of symmetry, then it is possible to invert the time-dependent line profiles and obtain the phase space distribution of the emission-line gas: i.e., its emissivity and the moments of its velocity distributions as functions of position. The cases of spherical and disk symmetry are considered in detail; the case of a straight jet, which may be relevent to correlated optical and radio variations, is discussed briefly. Explicit calculations of expected line variations have been carried out for several simple models. We suggest that with recently developed instrumentation it should now be possible to apply this technique to Seyfert galaxies. Long term, highly accurate observations will be required for the application to quasars.

• Research Organization: Theoretical Astrophysics, California Institute of Technology
• OSTI ID: 5080299
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 255:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC GASES
COSMIC RADIO SOURCES
DISTRIBUTION
EMISSION SPECTRA
EMISSIVITY
FLUIDS
FUNCTIONS
GALAXIES
GALAXY NUCLEI
GASES
JETS
LUMINOSITY
MATHEMATICAL SPACE
OPTICAL PROPERTIES
PHASE SPACE
PHYSICAL PROPERTIES
QUASARS
RADIATION TRANSPORT
SEYFERT GALAXIES
SPACE
SPATIAL DISTRIBUTION
SPECTRA
SURFACE PROPERTIES
TRANSFER FUNCTIONS
TRANSPORT THEORY