NASA/IPAC EXTRAGALACTIC DATABASE
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For refcode 1997AJ....114.1345V:
Retrieve 44 NED objects in this reference.
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Copyright by American Astronomical Society. Reproduced by permission
1997AJ....114.1345V SPECTROSCOPY OF SEYFERT 2 GALAXIES, LINERS, AND H II GALAXIES M. S. VACELI, S. M. VIEGAS, R. GRUENWALD, AND R. E. DE SOUSA Instituto Astronomico e Geofisico. Univ. Sao Paulo, Brazil Electronic mail: (salete,viegas,ruth,ronaldo)@iagusp.br Received 1996 December 17; revised 1997 June 19 ABSTRACT We present here 46 optical spectra of active objects, including Seyfert 2 galaxies (Sy 2), H II galaxies, and LINERs (Low Ionization Nuclear Emission-line Region), observed with low resolution (4 A) at LNA/CNPq in 1991 and 1994. The extraction of the stellar contribution due to the host galaxy is made through the subtraction of templates built from a stellar population synthesis in normal nuclei of S and E/S0 galaxies (Bica 1988, A&A, 195,76). In Sy 2 and LINERs, an old high metallicity population is predominant, while in H II galaxies, as expected, a younger population predominates. The residual optical continuum of the Sy 2 and LINERs approaches a power law and may correspond to a nonthermal radiation originating in the galactic center. However, the determination of the corresponding spectral index is strongly dependent on the stellar population subtraction. The emission-line intensities are also presented, and were obtained after the stellar population subtraction. The enhancement of H{beta} and [N I] {lambda}5200, relative to the unprocessed spectra, is significant (20% and 40% on the average, respectively). The decrease in intensity of He I k5876 (15% on the average) is very important, since it is usually used to calculate the helium abundance in extragalactic H II regions, from which the He primordial abundance is inferred.
Retrieve 44 NED objects in this reference.
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