We report the discovery of five Narrow-Line Seyfert 1 galaxies (NLSls) identified from the ROSAT All-Sky Survey bright sources. One of them has a quasar-like luminosity and two, including the quasar-like one, have clo...We report the discovery of five Narrow-Line Seyfert 1 galaxies (NLSls) identified from the ROSAT All-Sky Survey bright sources. One of them has a quasar-like luminosity and two, including the quasar-like one, have close companions and/or show interacting features. We calculate the central black hole masses and Eddington ratios for the five NLSls. In combination with the objects of Kaspi et al., we find that NLSls have smaller central black hole masses and higher accretion rate than normal Seyfert 1s.展开更多
The optical spectrum of SDSS J022119.84 + 005628.4 (R. A. = 02h 21m 19.84s, Dec = 00°56' 28.4', J2000; z = 0.399785 ± 0.000558) is analyzed by multi-component profile modelling. The small flux ratio ...The optical spectrum of SDSS J022119.84 + 005628.4 (R. A. = 02h 21m 19.84s, Dec = 00°56' 28.4', J2000; z = 0.399785 ± 0.000558) is analyzed by multi-component profile modelling. The small flux ratio of [OⅢ]NC/Hβ (=0.78) and FWHM(HβBC) = 1778.1 ±85.9 km s-1 led us to identify SDSS J022119.84 + 005628.4 as a Narrow-line Seyfert 1 galaxy with RFe= 1.4-1.0+1.0 and intermediate radio loudness, logR = 1.93. The continuum low jump at the Balmer limit might be contributed by a starburst component, which suggests that the object is a relatively young AGN with star-formation activity in its inner region. This provides a useful observational test of the AGN evolution. The low flux ratio of the narrow components, [OⅢ]/Hβ = 1.62, and the prominent [OⅡ]γ3727 emission, [OⅡ]/[OⅢ] = 2.24, suggests that there should be a group of AGNs different from Seyfert 2s when their broad line regions are obscured by the torus on the line of sight. A possible orientation effect is suggested to interpret the observed Seyfert 1.5s-like spectrum of the object. The spectrum features prominent broad blue wings of both [OⅢ]γγ4959 and 5007. After excluding other possible contributions, we conclude that the broad components are emitted by [O Ⅲ] itself. The material emitting the broad [O III] line is probably situated in a transient line region (with a low electron density, ne < 107cm-3) between the broad line region (BLR) and the narrow line region (NLR). The object can be classified as a 'blue outlier' defined by Zamanov et al., according to its velocity shift vr([OⅢ]) = -293.6 ± 18.0 km s-1, relative to the systematic velocity.展开更多
文摘We report the discovery of five Narrow-Line Seyfert 1 galaxies (NLSls) identified from the ROSAT All-Sky Survey bright sources. One of them has a quasar-like luminosity and two, including the quasar-like one, have close companions and/or show interacting features. We calculate the central black hole masses and Eddington ratios for the five NLSls. In combination with the objects of Kaspi et al., we find that NLSls have smaller central black hole masses and higher accretion rate than normal Seyfert 1s.
基金Supported by the National Natural Science Foundation of China.
文摘The optical spectrum of SDSS J022119.84 + 005628.4 (R. A. = 02h 21m 19.84s, Dec = 00°56' 28.4', J2000; z = 0.399785 ± 0.000558) is analyzed by multi-component profile modelling. The small flux ratio of [OⅢ]NC/Hβ (=0.78) and FWHM(HβBC) = 1778.1 ±85.9 km s-1 led us to identify SDSS J022119.84 + 005628.4 as a Narrow-line Seyfert 1 galaxy with RFe= 1.4-1.0+1.0 and intermediate radio loudness, logR = 1.93. The continuum low jump at the Balmer limit might be contributed by a starburst component, which suggests that the object is a relatively young AGN with star-formation activity in its inner region. This provides a useful observational test of the AGN evolution. The low flux ratio of the narrow components, [OⅢ]/Hβ = 1.62, and the prominent [OⅡ]γ3727 emission, [OⅡ]/[OⅢ] = 2.24, suggests that there should be a group of AGNs different from Seyfert 2s when their broad line regions are obscured by the torus on the line of sight. A possible orientation effect is suggested to interpret the observed Seyfert 1.5s-like spectrum of the object. The spectrum features prominent broad blue wings of both [OⅢ]γγ4959 and 5007. After excluding other possible contributions, we conclude that the broad components are emitted by [O Ⅲ] itself. The material emitting the broad [O III] line is probably situated in a transient line region (with a low electron density, ne < 107cm-3) between the broad line region (BLR) and the narrow line region (NLR). The object can be classified as a 'blue outlier' defined by Zamanov et al., according to its velocity shift vr([OⅢ]) = -293.6 ± 18.0 km s-1, relative to the systematic velocity.
