Thesis (Ph.D.)--University of California, Santa Cruz, 1976.
|Statement||Alan Thomas Koski.|
adshelp[at] The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86ACited by: 1. It is found that: (1) there are no distinguishing differences between the spectra of Seyfert 2 galaxies and narrow-line radio galaxies; (2) the emission spectra are rich in lines from a wide range of ionization levels; (3) the continuum is starlight diluted by an underlying continuous spectrum; (4) the line widths of both classes of galaxies have the same distribution; (5) there appear to be regions of Author: A. T. Koski. Spectrophotometric measurements are presented of the emission lines in seven narrow-line radio galaxies. The resulting emission-line ratios, corrected for interstellar extinction on the basis of the H I Balmer-line ratios, are combined with previously published results for other narrow-line radio galaxies and Seyfert 2 by: , a narrow-line Seyfert 1 (NLS1) galaxy with a recently discovered extended radio emission (Congiu et al., a). 2 SAMPLE AND OBSERVATIONS IC and NGC, two Seyfert 2 galaxies with well known ENLR were the targets of our observations. IC is a lenticular galaxy (z= ) characterized by a complex system of dust lanes, aligned.
No. 2, NARROW-LINE SEYFERT 1 GALAXIES FIG. 2.¨Example of the Fe II subtraction procedure carried out to the NLS1 galaxies 1H [ (top panel), CTS R (middle panel), and. Download PDF Abstract: I provide a short review of the properties of Narrow-line Seyfert 1 (NLS1) galaxies across the electromagnetic spectrum and of the models to explain them. Their continuum and emission-line properties manifest one extreme form of Seyfert activity. As such, NLS1 galaxies may hold important clues to the key parameters that drive nuclear activity. at a diﬀerent angle would become a regular Seyfert galaxy (type 1 or 2 as always depending on the obscuration) but, because of its radio emission, it would be classiﬁed as a broad- or narrow-line radio galaxy. Since NLS1s seem always to be hosted in disk galaxies, the BLRG or NLRG should also be hosted in a disk galaxy (both spiral and. narrow line Seyfert 1 galaxies NLSy1 galaxies are radio-loud having the radio loudness parame-ter R > 10 (R is deﬁned as the ratio of the radio ﬂux density at 5 GHz to the optical ﬂux density at nm (Kellermann et al. ) and among them about 2% − 3% are very radio-loud (R> ).
A SAMPLE OF SEYFERT-2 GALAXIES WITH ULTRALUMINOUS GALAXY-WIDE NARROW-LINE REGIONS: QUASAR LIGHT ECHOES?∗ M. Schirmer 1,2,3, K. Holhjem4, N. A. Levenson 1, and C. Winge 1 Gemini Observatory, Casilla , La Serena, Chile 2 Argelander-Institut fur Astronomie, Universit ¨at Bonn, Auf dem Hu D Bonn, Germany 3 ICATE, CONICET. In addition to the Seyfert progression from Type I to Type II (including Type to Type ), there are other types of galaxies that are very similar to Seyferts or that can be considered as subclasses of them. Very similar to Seyferts are the low-ionisation narrow-line emission radio galaxies . This paper presents a comparative study of emission line ratios of the Narrow Line Region (NLR) of Seyfert 1 and Seyfert 2 galaxies. It includes a literature compilation of the emission line fluxes [OII]A, [NeIII]A, [OIII]A and [NeV]A, as well as 60mum continuum flux, for a sample of 52 Seyfert 1's and 68 Seyfert 2's. Seyfert 1 and 2 galaxy samples The Seyfert 2 galaxies sample is selected from the galaxy catalog of SDSS Data Release 4 (DR4). For our purpose, a redshift cut of z.