Several authors have recently explored, for narrow-line Seyfert 1 galaxies (NLS1s), the relationship between black hole mass (MBH) and stellar velocity dispersion (σ*). Their results are more or less in agreement and seem to indicate that NLS1s fill the region below the fit obtained by Tremaine et al., showing a range of σ* similar to that of Seyfert 1 galaxies, and a lower MBH. Until now, the [OIII] width has been used in place of the stellar velocity dispersion, but some indications have begun to arise against the effectiveness of the gaseous kinematics in representing the bulge potential, at least in NLS1s. Bian & Zhao have stressed the urgency of producing true σ* measurements. Here, we present new stellar velocity dispersions obtained through direct measurements of the CaII absorption triplet (~8550 Å) in the nuclei of eight NLS1 galaxies. The resulting σ* values and a comparison with σ[OIII] confirm our suspicion that [OIII] typically overestimates the stellar velocity dispersion. We demonstrate that NLS1s follow the MBH-σ* relation as Seyfert 1, quasars and non-active galaxies.

Stellar velocity dispersion in narrow-line Seyfert 1 galaxies

BOTTE, VIRGINIA;CIROI, STEFANO;DI MILLE, FRANCESCO;RAFANELLI, PIERO;ROMANO, ANNA
2005

Abstract

Several authors have recently explored, for narrow-line Seyfert 1 galaxies (NLS1s), the relationship between black hole mass (MBH) and stellar velocity dispersion (σ*). Their results are more or less in agreement and seem to indicate that NLS1s fill the region below the fit obtained by Tremaine et al., showing a range of σ* similar to that of Seyfert 1 galaxies, and a lower MBH. Until now, the [OIII] width has been used in place of the stellar velocity dispersion, but some indications have begun to arise against the effectiveness of the gaseous kinematics in representing the bulge potential, at least in NLS1s. Bian & Zhao have stressed the urgency of producing true σ* measurements. Here, we present new stellar velocity dispersions obtained through direct measurements of the CaII absorption triplet (~8550 Å) in the nuclei of eight NLS1 galaxies. The resulting σ* values and a comparison with σ[OIII] confirm our suspicion that [OIII] typically overestimates the stellar velocity dispersion. We demonstrate that NLS1s follow the MBH-σ* relation as Seyfert 1, quasars and non-active galaxies.
File in questo prodotto:
File Dimensione Formato  
ciroi2.pdf

accesso aperto

Tipologia: Published (publisher's version)
Licenza: Accesso libero
Dimensione 79.86 kB
Formato Adobe PDF
79.86 kB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/2431321
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 53
  • ???jsp.display-item.citation.isi??? 54
social impact