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Date and Time of the Query: 2019-08-20 T06:47:06 PDT
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For refcode 1990ApJ...352..561O:
Retrieve 16 NED objects in this reference.
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1990ApJ...352..561O NEAR-INFRARED EMISSION-LINE SPECTRA OF THE ORION NEBULA, NGC 4151, AND OTHER SEYFERT GALAXIES DONALD E. OSTERBROCK, RICHARD A. SHAW, AND SYLVAIN VEILLEUX University of California Observatories/Lick Observatory and Board of Studies in Astronomy and Astrophysics, University of California, Santa Cruz Received 1989 July 17; accepted 1989 September 25 ABSTRACT Near-infrared CCD spectra, covering the wavelength interval of approximately {lambda}{lambda}7000-11000 at moderate resolution (FWHM ~ 6 A), were obtained of NGC 1976 and NGC 4151 in three overlapping segments. The wavelengths and relative line fluxes were measured, and most of the lines were identified. The strongest three lines in both objects are, in order, [S III] {lambda}9531, He I {lambda}10830, and [S III] {lambda}9069. The Orion Nebula spectrum is very helpful for identifying lines in NGC 4151 and for comparison with it. Among the ions identified in NGC 1976, many of them previously known, are [Fe II], [Ni II], [Ni III], [Cl II], and [C I]. Likewise, in NGC 4151, [C I], [Fe II], [Fe XI], [Cl II], [Ni II], [Ar III], [Ar V], and [S II] are all present, and probably [S VIII] as well, in addition to H I, He I, and He II. Lower resolution (FWHM ~ 12 A) spectra covering the range {lambda}{lambda}7000-10000 of 14 additional Seyfert galaxies were also obtained and measured. The strongest line in all but two of them is [S III] {lambda}9531. Nearly all these galaxies show the strongest [Ni II] line, {lambda}7378. Comparison of line strengths among these various Seyfert galaxies allow the ionization behavior to be traced. One unidentified line, {lambda}7865, that is present in the spectra of NGC 4151, III Zw 77, and three other galaxies, is probably a high-ionization forbidden line. Two other unidentified emission lines apparently observed in two or more Seyfert galaxies are {lambda}9138 and {lambda}9191. The best additional diagnostic information the near-infrared spectral region provides, the [S III] ({lambda}9069 + {lambda}9531)/{lambda}6312 ratio, is not as useful as the analogous [O III] ratio, due to the blending of {lambda}6312 and the greater wavelength interval of the [S III] ratio. Subject headings: galaxies: individual (NGC 4151) - galaxies: Seyfert - infrared: spectra - line identifications - nebulae: Orion Nebula
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