In studying Ca II λλλ 8498,8542,8662 spectral region of NLS1, we have observed that 7 NLS1 do not show O I λ 8446 line emission. We have investigated the reasons of this disappearing analysing the excitation mechanism of O I λ 8446 and the physical conditions of BLR that permit its emission. With a preliminary study of BLR properties we have found that O I λ 8446 emission required a density n_H between 1E11 and 1E12 and ionization parameter U between -1.8 and -3 in logarithm.
The O I λ8446 emission line in NLS1 galaxies
CIROI, STEFANO;DI MILLE, FRANCESCO;RAFANELLI, PIERO
2007
Abstract
In studying Ca II λλλ 8498,8542,8662 spectral region of NLS1, we have observed that 7 NLS1 do not show O I λ 8446 line emission. We have investigated the reasons of this disappearing analysing the excitation mechanism of O I λ 8446 and the physical conditions of BLR that permit its emission. With a preliminary study of BLR properties we have found that O I λ 8446 emission required a density n_H between 1E11 and 1E12 and ionization parameter U between -1.8 and -3 in logarithm.File in questo prodotto:
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