Sign on
ADS Classic is now deprecated. It will be completely retired in October 2019. Please redirect your searches to the new ADS modern form or the classic form. More info can be found on our blog.

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· On-line Data
· References in the article
· Citations to the Article (87) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (18)
· NED Objects (19)
· Also-Read Articles (Reads History)
· Translate This Page
Infrared, optical, and ultraviolet observations of hydrogen line emission from Seyfert galaxies
Lacy, J. H.; Soifer, B. T.; Neugebauer, G.; Matthews, K.; Malkan, M.; Becklin, E. E.; Wy, C. C.; Boggess, A.; Gull, T. R.
AA(California Institute of Technology; Palomar Observatory, Pasadena, CA), AB(California Institute of Technology; Palomar Observatory, Pasadena, CA), AC(Hawaii, University, Honolulu, HI)
Astrophysical Journal, Part 1, vol. 256, May 1, 1982, p. 75-82. NSF-NASA-supported research. (ApJ Homepage)
Publication Date:
NASA/STI Keywords:
Galactic Radiation, H Lines, Infrared Astronomy, Lyman Alpha Radiation, Seyfert Galaxies, Ultraviolet Spectra, Balmer Series, Emission Spectra, Galactic Nuclei, Infrared Telescopes, Interstellar Extinction, Iue, Quasars, Radiant Flux Density, Radio Galaxies, Visual Observation
Bibliographic Code:


Nearly simultaneous observations are reported of P-alpha, H-alpha, and H-beta emission from 18 Seyfert galaxies and of Ly-alpha from eight of these galaxies. In many cases, P-alpha is stronger relative to the Balmer lines than is predicted by recombination calculations; reddening appears to be required. Dispersion in the P-alpha/H-alpha/H-beta ratios orthogonal to the reddening track indicates that high densities or optical depths also affect the line flux ratios. Several galaxies, notably NGC 1275, have very low P-alpha/H-alpha ratios. High densities, large optical depths, and reddening probably all contribute to the low observed Ly-alpha/H-beta ratios.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences

More Article Retrieval Options

HELP for Article Retrieval

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)

Find Similar Abstracts:

Use: Authors
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
arXiv e-prints