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IUE and visual spectrophotometry of Markarian 9, Markarian 10, and 3C 390.3Ultraviolet spectra from IUE are combined with visual spectra for the three type I Seyfert galaxies Mrk 9, Mrk 10, and 3C 390.3. The 2175 A interstellar feature is measured well enough in Mrk 9 to indicate that the extinction corresponding to E(B-V) = 0.14 + or - 0.04 is in the galaxy. Mrk 10 displays evidence for 2175 A absorption and also yields E(B-V) = 0.14 + or - 0.07, while the continuum for 3C 390.3 is too weak to positively detect the feature. It is found, after correcting for reddening, that the line-intensity ratio L(alpha)/H(beta) ranges from 8 to 18, while that for H(alpha)/H(beta) goes from 2.1 to 5.4. It is noted that the He II 1640/4686 line ratio is uncertain but appears to be consistent with the recombination value of about 8. If photoionization is assumed, a comparison of the strengths of L(alpha) and H(beta) with the UV ionizing flux suggests that H(beta) is enhanced rather than L(alpha) depressed. When a comparison is made with similar ratios in quasars, L(alpha) is found to be much stronger and H(beta) slightly stronger in Seyferts than in quasars.
Document ID
19810042304
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Oke, J. B.
(California Inst. of Tech. Pasadena, CA, United States)
Goodrich, R. W.
(Palomar Observatory Pasadena, Calif., United States)
Date Acquired
August 11, 2013
Publication Date
January 15, 1981
Publication Information
Publication: Astrophysical Journal
Subject Category
Astrophysics
Accession Number
81A26708
Funding Number(s)
CONTRACT_GRANT: NGL-05-002-134
CONTRACT_GRANT: NSG-5243
Distribution Limits
Public
Copyright
Other

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