Obscuration and the various kinds of Seyfert galaxies

Journal Article · Sat May 15 04:00:00 EDT 1982 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/159918· OSTI ID:5023056

Lawrence, A; Elvis, M

For a complete hard X-ray selected sample of active spiral galaxies we have collected luminosities of HX = L/sub x/ (2--10 keV), H..beta.. lambda4861, (O III) lambda5007, and 3.5 ..mu..m (L3.5). The effect found by Keel, that optically selected Seyfert galaxies tend to be face-on, is removed. Most of the X-ray discovered objects are ''narrow emission line galaxies'' (NELGs). We find that they are both selectively edge-on and lower in HX than the sample as a whole. At least some NELGs have large X-ray absorbing columns, so we believe that both the axial ratio and luminosity effects are due to obscuration. We also find that edge-on galaxies have low H..beta../HX; however, no effect with axial ratio is seen with O III/HX or L3.5/HX. We thus believe that obscuration takes place in or just around the broad line region (BLR), which has a flattened configuration parallel to the disk of the parent galaxy.

• Research Organization: Department of Physics and Center for Space Research, Massachusetts Institute of Technology
• OSTI ID: 5023056
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 256:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640103 -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
GALAXIES
GALAXY NUCLEI
HARD X RADIATION
IONIZING RADIATIONS
LINE WIDTHS
LUMINOSITY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
SEYFERT GALAXIES
SOFT X RADIATION
SPECTRA
X RADIATION
X-RAY GALAXIES