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Träfflista för sökning "L773:0004 6361 OR L773:1432 0746 srt2:(1985-1989)"

Sökning: L773:0004 6361 OR L773:1432 0746 > (1985-1989)

  • Resultat 11-13 av 13
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11.
  • van Groningen, E., et al. (författare)
  • Broad emission line profiles in Seyfert-1 galaxies : [O III]-wings from a transition zone
  • 1989
  • Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 211:2, s. 293-309309
  • Tidskriftsartikel (refereegranskat)abstract
    • The authors demonstrate that broad wings are present under the strong [O III] lambda 5007 line in 10 out of 12 observed Seyfert-1 galaxies. The question is addressed whether the wing is due to broad [O III] emission or to some other ion. The alternatives considered are Fe II (42) lambda 5018, He I lambda 5016 and Si II lambdalambda 5041, 5056 or even Hbeta. The authors have searched for a counterpart of the wing in other forbidden and permitted lines. The observations yield a crude estimate of the density in the wing-emitting region. The authors derive a lower limit to the region's size. Because the [O III] emitting gas holds an intermediate position between the broad line region (BRL) and the narrow line region (NLR), both in density and distance, the authors denominate it the transition line region (TLR). They surmise that the outflowing part of the BLR provides the material of the TLR, before slowing down to NLR velocities
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12.
  • van Groningen, E. (författare)
  • Broad emission line profiles in Seyfert-1 galaxies. I. Evidence for a disk and a wind in Mkn 335
  • 1987
  • Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 186:1-2, s. 103-113113
  • Tidskriftsartikel (refereegranskat)abstract
    • High resolution spectroscopic observations of the Seyfert-1 galaxy Mkn 335 are presented. This galaxy is exceptional in the sense that its broad emission lines display a strong blue asymmetry. It is shown that the Halpha/Hbeta intensity ratio changes drastically with velocity shift. It is also found that the Hdelta/Hbeta ratio varies only by a small amount from line core to the wings, and is close to the theoretical case B recombination value. It is proposed that these Balmer line ratios are produced by a medium with very high densities and a temperature of about 10 4 K. These observations are interpreted by a model with two dynamically and spatially separate components: a disk which contains the very high density material and emits ~80% of the Balmer lines in a symmetric profile and an outflowing component of much lower density which emits the blue wing and most of Ly alpha and the higher excitation lines (such as C IV lambda1549)
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  • Resultat 11-13 av 13

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