Emission line variation in the Seyfert galaxy Fairall 9 and the presence of broad [O III] emission

• 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

Ämnesord

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

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

Nyckelord

Experimental/ astronomical spectra

iron

oxygen

Seyfert galaxies

visible astronomical observations/ visible

forbidden line

O III

AD 1982

AD 1987

Seyfert galaxy

Fairall 9

spectra

Hbeta region

broad lines

Fe II

500.7 to 516.9 nm

O

Fe/ A9850R Active and peculiar galaxies A9850G Radiation and spectra of galaxies A9580J Photographic region astronomical observations/ wavelength 5.007E-07 to 5.169E-07 m/ O/el

Fe/el

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)