The featureless continua and hydrogen lines of Seyfert 2 galaxies

Journal Article · Thu Aug 01 04:00:00 EDT 1991 · Astrophysical Journal; (United States)

DOI:https://doi.org/10.1086/170339· OSTI ID:5257707

Kinney, A L; Antonucci, R R.J.; Ward, M J; Wilson, A S; Whittle, M ^[1]

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1. Space Telescope Science Inst., Baltimore, MD (United States) California Univ., Santa Barbara (United States) Oxford Univ. (England) Maryland Univ., College Park (United States) Virginia Univ., Charlottesville (United States)

Optical and ultraviolet spectra taken in similar sized large apertures for 15 Seyfert 2 galaxies are presented. Measurements of emission-line strengths of Ly-alpha, H-alpha, and H-beta are used together with measurements of the ultraviolet slopes to estimate the ratio of recombination photons to ionizing photons. The photon ratios indicate that the ionizing continuum is being emitted anisotropically for at least six of the eight objects with UV slope measurements. The median value of the UV slope is indistinguishable from the UV slope of Seyfert 1 galaxies. This result suggests that in the occultation/reflection picture of Seyfert nuclei, the reflecting particles are free electrons and not dust. Previous observations of variability in Mrk 477 are verified, and it is shown that this galaxy exhibits characteristics of both Seyfert 1 and Seyfert 2 galaxies. 90 refs.

• OSTI ID: 5257707
• Journal Information: Astrophysical Journal; (United States), Journal Name: Astrophysical Journal; (United States) Vol. 377; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BALMER LINES
BOSONS
DATA
ELECTRONS
ELEMENTARY PARTICLES
EMISSION SPECTRA
FERMIONS
GALAXIES
GALAXY NUCLEI
INFORMATION
LEPTONS
LYMAN LINES
MARKARIAN GALAXIES
MASSLESS PARTICLES
PHOTONS
SEYFERT GALAXIES
SPECTRA
ULTRAVIOLET SPECTRA
VARIATIONS
VISIBLE SPECTRA