The Narrow‐Line Region of Seyfert Galaxies: Narrow‐Line Seyfert 1 Galaxies versus Broad‐Line Seyfert 1 Galaxies

Nagao, Tohru; Murayama, Takashi; Taniguchi, Yoshiaki

doi:10.1086/318300

Cited by 54 publications

(52 citation statements)

References 74 publications

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“…In our spectrum, the Paα line can be separated into a broad and a narrow component with the broad component showing a width of 2081 km s −1 which is typical for a narrow line Seyfert 1 galaxy. This is consistent with the findings of Nagao et al (2001) and Rodríguez-Ardila et al (2000b) who determined the FWHM of Hα to be 1870 km s −1 and classified the object as a narrow line Seyfert 1 galaxy, too. As in HE 1013-1947, the broad component's shape looks slightly asymmetric what could be caused by an unresolved helium-line.…”

Section: He 1029-1831supporting

confidence: 92%

“…Nagao et al (2001) as well as Rodríguez-Ardila et al (2000b) find HE 1013-1947 to be a narrow line Seyfert 1 galaxy with a broad component in Hα and Hβ of about 1900 km s −1 , which is narrower than the line width we extracted using Paα.s The difference between the optical and NIR-linewidths could be explained by extinction effects. The slight blueshift of the center of the broad component versus the center of the narrow component could indicate that an unresolved He line (λ1.838 µm) influences our measurement.…”

Section: He 1013-1947mentioning

confidence: 58%

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Nearby AGN and their hosts in the near infrared

Fischer

Iserlohe

Zuther

et al. 2006

A&A

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We present near infrared ISAAC VLT observations of nine nearby (0.01 ≤ z ≤ 0.06) Active Galactic Nuclei selected from the Hamburg/ESO Survey and the Véron-Cetty & Véron catalog. Hydrogen recombination lines Paα and Brγ are observed in seven of the nine sources of which five show a broad component. In three sources, extended 1-0S(1) rotational-vibrational molecular hydrogen emission is detected. Stellar CO absorption is seen in four sources. In one of these objects, an upper limit of the central mass can be determined from the stellar velocity field. H-and Ks-band imaging allow us to determine the morphology class of the host galaxies. Colors (with supplementary J-band 2MASS images) show that the four galaxies with detected CO absorption are characterized by an overall strong stellar contribution. One galaxy shows an increased extinction towards the nucleus. After removal of the nuclear point source, the host galaxies show colors typical for non-active spiral galaxies.

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Section: He 1029-1831supporting

confidence: 92%

Section: He 1013-1947mentioning

confidence: 58%

Nearby AGN and their hosts in the near infrared

Fischer

Iserlohe

Zuther

et al. 2006

A&A

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“…If the line width is under estimated by a factor of 2, then the BH mass can be as large as that of a typical radio-loud quasars in the BQS sample. Since this object possesses all properties of an NLS1, it comes to the question of whether the NLS1 phenomena is an orientation effect, i.e., a flat BLR seen face-on (Nagao, Murayama, & Taniguchi 2001) or is due to different physical parameters such as a large L=L Edd (BG92). The radio properties suggest that this object is seen at a small inclination angle, but the picture of a small BH mass and a large accretion rate is also self-consistent.…”

Section: Discussionmentioning

confidence: 99%

SDSS J094857.3+002225: A Very Radio Loud, Narrow‐Line Quasar with Relativistic Jets?

Zhou

Wang

Dong

et al. 2003

ApJ

163

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We report the identification of a very radio loud, narrow-line quasar, SDSS J094857.3+002225, discovered in the Sloan Digital Sky Survey (SDSS) early data release (EDR). With FWHM ðH Þ % 1500 km s À1 and undetected [O iii] 4959, 5007 SDSS J094857.3+002225 is consistent with the conventional definition of narrow-line Seyfert 1 galaxies (NLS1s). Its strong optical Fe ii emission [R 4570 f ðFe ii 4570Þ= f ðH Þ % 1:59] is also typical of NLS1s. With a radio loudness RL ð f ;4:85 GHz =f ;B Þe1000 and radio power of P 4:85 GHz $ ð3:6 5:2Þ Â 10 26 W Hz À1 , it is the first bona fide, very radio loud NLS1. The inverted radio spectrum and very high brightness temperature (e10 13 K) derived from variation of the radio flux suggest the presence of a relativistic jet beaming toward the observer in this NLS1.

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“…This is most probably due to the fact that they modelled the broad Balmer component with a Gaussian rather than a Lorentzian. On the other hand, Nagao et al (2001) showed that the line ratios [ …”

Section: The Line Ratios Of the Narrow Line Regionmentioning

confidence: 99%

A spectrophotometric atlas of Narrow-Line Seyfert 1 galaxies

Véron-Cetty

Véron

Gonçalves³

2001

A&A

283

324

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Abstract.We have compiled a list of 83 objects classified as Narrow-Line Seyfert 1 galaxies (NLS1s) or known to have a broad Balmer component narrower than 2 000 km s −1 . Of these, 19 turned out to have been spectroscopically misidentified in previous studies; only 64 of the selected objects are genuine NLS1s. We have spectroscopically observed 59 of them and tried to characterize their Narrow and Broad-Line Regions (NLR and BLR) by fitting the emission-lines with Gaussian and/or Lorentzian profiles. In most cases, the broad Balmer components are well fitted by a single Lorentzian profile, confirming previous claims that Lorentzian rather than Gaussian profiles are better suited to reproduce the shape of the NLS1s broad emission lines. This has consequences concerning their FWHMs and line ratios: when the broad Balmer components are fitted with a Lorentzian, most narrow line regions have line ratios typical of Seyfert 2s while, when a Gaussian profile is used for fitting the broad Balmer components, the line ratios are widely scattered in the usual diagnostic diagrams (Veilleux & Osterbrock 1987); moreover, the FWHM of the best fitting Lorentzian is systematically smaller than the FWHM of the Gaussian. We find that, in general, the [O III] lines have a relatively narrow Gaussian profile (∼200-500 km s −1 FWHM) with often, in addition, a second broad (∼500-1 800 km s −1 FWHM), blueshifted Gaussian component. We do not confirm that the [O III] lines are weak in NLS1s. As previously suggested, there is a continuous transition of all properties between NLS1s and classical Broad-Line Seyfert 1 Galaxies (BLS1s) and the limit of 2000 km s −1 used to separate the two species is arbitrary; R4570, the ratio of the Fe II to the Hβ fluxes, could be a physically more meaningful parameter to distinguish them.

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The Narrow‐Line Region of Seyfert Galaxies: Narrow‐Line Seyfert 1 Galaxies versus Broad‐Line Seyfert 1 Galaxies

Cited by 54 publications

References 74 publications

Nearby AGN and their hosts in the near infrared

Nearby AGN and their hosts in the near infrared

SDSS J094857.3+002225: A Very Radio Loud, Narrow‐Line Quasar with Relativistic Jets?

A spectrophotometric atlas of Narrow-Line Seyfert 1 galaxies

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