Broad emission line profiles in Seyfert-1 galaxies : [O III]-wings from a transition zone

• 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

Ämnesord

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Nyckelord

Experimental/ astronomical spectra

interstellar matter

oxygen

Seyfert galaxies

visible astronomical observations/ interstellar matter

visible

AD 1982 09 to 10

forbidden line

emission line profiles

Seyfert-1 galaxies

transition zone

broad wings

Fe II

He I

Si II

Hbeta

permitted lines

density

wing-emitting region

size

broad line region

narrow line region

transition line region

velocities

351 to 754 nm/ A9850R Active and peculiar galaxies A9850E Galactic structure

content and morphology A9580J Photographic region astronomical observations A9840B Interstellar matter/ wavelength 3.51E-07 to 7.54E-07 m

Publikations- och innehållstyp

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