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Träfflista för sökning "WFRF:(van Groningen E.) srt2:(1985-1989);srt2:(1989)"

Sökning: WFRF:(van Groningen E.) > (1985-1989) > (1989)

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1.
  • Stirpe, G. M., et al. (författare)
  • Emission line variation in the Seyfert galaxy Fairall 9 and the presence of broad [O III] emission
  • 1989
  • Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 211:2, s. 310-314314
  • Tidskriftsartikel (refereegranskat)abstract
    • The authors present two high quality spectra of the Hbeta region in the Seyfert 1 galaxy Fairall 9, separated by a period of 4 years. The variation of the broad lines is discussed, and in particular that of the Fe II lines of multiplet 42. The difference spectrum shows clearly Fe II (42) lambda 5018 and lambda 5169 with equal intensity. There is a strong, broad (4000 km s -1) wing present under the [O III] lambda 5007 line, which varied only by a small amount. The authors show that this variation is entirely due to the variation of Fe II lambda 5018 and that the remainder of the [O III]-wing has not varied. On this basis the authors argue that the wing is not caused by the Fe II (42) lambda 5018 line, nor by any other Fe II lines, but that they are observing high velocity [O III]-emitting material. From the lack of variation in this component a minimum distance to the source can be set of 1.3 pc. Other features of the difference spectrum are also discussed
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2.
  • 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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  • Resultat 1-2 av 2
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tidskriftsartikel (2)
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refereegranskat (2)
Författare/redaktör
de Bruyn, A. G. (2)
van Groningen, E. (2)
Stirpe, G. M. (1)
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Uppsala universitet (2)
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Engelska (2)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (2)
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