Open Access[O iii ] emission line in narrow‐line Seyfert 1 galaxies
Author(s) -
Bian Weihao,
Yuan Qirong,
Zhao Yongheng
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.10026.x
Subject(s) - physics , astrophysics , doubly ionized oxygen , galaxy , velocity dispersion , line (geometry) , sky , emission spectrum , bulge , active galactic nucleus , laser linewidth , spectral line , black hole (networking) , astronomy , optics , geometry , computer network , laser , routing protocol , mathematics , routing (electronic design automation) , link state routing protocol , computer science
Three sets of two‐component profiles are used to simultaneously model the [O iii ]λλ4959, 5007 and Hβ lines for the Fe ii ‐subtracted spectra of 149 narrow‐line Seyfert 1 galaxies (NLS1s) from the Sloan Digital Sky Survey (SDSS). Using the linewidth of the narrow/core component of [O iii ]λ5007 to trace the stellar velocity dispersion instead of using the total linewidth of [O iii ]λ5007, we found that the SDSS NLS1s are still deviated from the M bh −σ relation found in the nearby inactive galaxies. This suggests that the linewidth of the [O iii ] narrow/core component is likely not a good tracer of bulge velocity dispersion in NLS1s, since some other studies indicate that NLS1s, like other active galactic nuclei (AGN), should follow the M bh −σ relation. If we assume that the [O iii ]5007/Hβ n line ratio emitted in the narrow‐line region (NLR) ranges from one to 10, 63 objects are found to be satisfied with this criterion, and their Hβ broad components should be used to calculate their virial black hole masses. These 63 objects are statically consistent with the M bh −σ [O III] relation. With the Chandra observation of some SDSS NLS1s, we find that one of these 63 objects (J143030.22‐001115.1) cannot be classified as a genuine NLS1. Its narrow component of Hβ is coming from NLRs. This is consistent with its very flat hard X‐ray spectrum found by researchers.