Astronomy and Astrophysics – Astrophysics
Scientific paper
1997-04-11
Astrophys.J.Suppl.112:391-414,1997
Astronomy and Astrophysics
Astrophysics
To appear in the Astrophysical Journal Supplements. LaTex, 32 pages, plus an additional 14 figures and 3 tables. AASTex macro
Scientific paper
10.1086/313042
We present the results of an optical spectroscopic survey designed to search for low-luminosity, "dwarf" Seyfert nuclei in a magnitude-limited sample of 486 bright, northern galaxies. Moderate-resolution spectra of exceptionally high quality were obtained in part to detect broad H-alpha emission, similar in character to, but much weaker than, the broad permitted lines that define type 1 Seyfert nuclei. One of the primary goals of the survey is to better quantify the faint end of the luminosity function of active galactic nuclei. This paper describes the subset of nuclei showing definite or probable evidence of broad H-alpha emission. We outline the procedures for determining the presence of this elusive spectral feature, steps for its quantitative measurement, and the associated systematic errors. Of the 211 emission-line galaxies classified as having Seyfert or LINER nuclei in our survey, the broad H-alpha line was detected with confidence in 34 objects, and with less certainty in another 12. Most of the detections are reported for the first time, and the detection rate represents a lower limit to the true incidence of active nuclei harboring a broad emission-line region. These statistics imply that broad-lined active nuclei are much more common than previously believed: they exist in at least 20% of all galaxies spectroscopically classified as "active" and in more than 10% of all luminous galaxies at the current epoch.
Filippenko Alexei V.
Ho Luis C.
Peng Chien Y.
Sargent Wallace L. W.
No associations
LandOfFree
A Search for "Dwarf" Seyfert Nuclei. IV. Nuclei with Broad H-alpha Emission does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Search for "Dwarf" Seyfert Nuclei. IV. Nuclei with Broad H-alpha Emission, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Search for "Dwarf" Seyfert Nuclei. IV. Nuclei with Broad H-alpha Emission will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-352713