by National Aeronautics and Space Administration, National Technical Information Service, distributor in [Washington, D.C.], [Springfield, Va .
Written in English
|Other titles||ROSAT annual status report.|
|Statement||prepared by Columbia Astrophysics Laboratory, Departments of Astronomy and Physics, Columbia University ; principal investigator, Jules P. Halpern.|
|Series||NASA contractor report -- NASA CR-199634.|
|Contributions||United States. National Aeronautics and Space Administration.|
|The Physical Object|
Diffuse emission and pathological Seyfert spectra Halpern, Jules P. Abstract. Not Available. Publication: Diffuse Emission and Pathological Seyfert Spectra. Pub Date: October Bibcode: .H Keywords: Binary Stars; Neutron Stars; Pulsars; Seyfert Galaxies; Sky Surveys (Astronomy); Spaceborne Astronomy; Author: Jules P. Halpern. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): In the unification scheme of Seyfert galaxies, a dusty torus blocks the continuum source and broad line region in Seyfert 2 galaxies. However it is not clear whether or not and to what extent the torus affects the narrow line spectra. In this paper, we show that Seyfert 1 and Seyfert 2 galaxies have different. spectra. In this Letter, we show that Seyfert 1 and Seyfert 2 galaxies have different distributions on the [O iii]/ Hb versus [N ii]/Ha diagram (BPT diagram) for narrow lines. Seyfert 2 galaxies display a clear left boundary on the BPT diagram and only % of them lie on the left. By contrast, Seyfert . FeII emission were carried out following the procedure as described in detail in Zhou et al. (). We ﬁt and subtracted the above model from the SDSS spectra, and then ﬁt emission lines using multi-gaussian model (see next section). Based on the ﬁtted emission-line parameters, we construct the sample of Sy1s according to the criteria as.
Only diffuse emission was detected in the rest of the field of view, with a deficit of emission at the position of the stellar nucleus. Diagnostic diagram analysis reveals that the off-centered emitting blob has a Seyfert 2 spectrum. We propose that the line-emitting blob may be a “fossil” emission-line region or a light “echo” from an. If soft line emission can be confirmed as a property of Seyfert Galaxies, then a combination of Seyfert 1 and 2 galaxies may be able to explain the spectrum of the diffuse X-ray background between — and keY. Seyfert galaxies were first detected in by Edward A. Fath and Vesto Slipher, who were using the Lick Observatory to look at the spectra of astronomical objects that were thought to be "spiral nebulae".They noticed that NGC showed six bright emission lines, which was considered unusual as most objects observed showed an absorption spectrum corresponding to stars. New observations are reported of J-band spectra (– μm) of three Seyfert 2 galaxies, Mkn 78 and NGC In each case the spectral range includes the near-infrared lines of [Fe.
Journals & Books; Help Vol Issue 5, May , Pages The average seyfert spectrum at gamma ray energies. Author links open overlay panel. 2. NGC a transmitted Seyfert 2 spectrum NGC , a S0-Sa Seyfert 2 galaxy seen al- most edge-on, is one of the narrow emission line galaxies in the HEAO 1 Piccinotti sample , and it is well studied in X-rays. The keV flux re- mained constant during at a level of xn erg cm-2 s-1 . Type 1 Seyfert galaxies have in their spectra:! • Narrow emission lines, with a width of several hundred km/s! • Broad emission lines, with widths up to km/s! They also have brighter and bluer nuclei! and the thermal emission from the hot gas in local hot bubble (LHB) (McCammon & Sanders ) are hard to be separated from each other using emission spectra above ∼ keV. In this energy range, the sum of the two emission components are approximated by a thin-thermal emission of kT ∼ keV without absorption (Smith et al.