Narrow-line region gas kinematics of 24 264 optically selected AGN: the radio connection

作者：Mullaney J R^*; Alexander D M; Fine S; Goulding A D; Harrison C M; Hickox R C

来源：Monthly Notices of the Royal Astronomical Society, 2013, 433(1): 622-638.

DOI：10.1093/mnras/stt751

• catalogues
• ISM: kinematics and dynamics
• galaxies: active
• quasars: emission lines
• radio continuum: galaxies

Using a sample of 24 264 optically selected active galactic nuclei (AGNs) from the SDSS DR7 data base, we characterize how the profile of the [O iii] lambda 5007 emission line relates to bolometric luminosity (L-AGN), Eddington ratio, radio loudness, radio luminosity (L-1.4 GHz) and optical class (i.e. broad/narrow-line Seyfert 1, type 2) to determine what drives the kinematics of this kpc-scale line emitting gas. First, we use spectral stacking to characterize how the average [O iii] lambda 5007 profile changes as a function of these five variables. After accounting for the known correlation between L-AGN and L-1.4 GHz, we report that L-1.4 GHz has the strongest influence on the [O iii] lambda 5007 profile, with AGNs of moderate radio luminosity (L-1.4 GHz = 10(23)-10(25) W Hz(-1)) having the broadest [O iii] lambda 5007 profiles. Conversely, we find only a modest change in the [O iii] lambda 5007 profile with increasing radio loudness and find no significant difference between the [O iii] lambda 5007 profiles of broad- and narrow-line Seyfert 1s. When binned according to Eddington ratio, only the AGNs in our highest bin (i.e. %26gt; 0.3) show any signs of having broadened [O iii] lambda 5007 profiles, although the small numbers of such extreme AGNs in our sample mean we cannot rule out that other processes (e.g. radio jets) are responsible for this broadening. The [O iii] lambda 5007 profiles of type 1 and type 2 AGNs show the same trends in terms of line width, but type 1 AGNs display a much stronger %26apos;blue wing%26apos;, which we interpret as evidence of outflowing ionized gas. We perform multicomponent fitting to the H beta, [O iii] lambda lambda 4959, 5007, [N ii] lambda lambda 6548, 6584 and H alpha lines for all the AGNs in our sample to calculate the proportions of AGNs with broad [O iii] lambda 5007 profiles. The individual fits confirm the results from our stacked spectra; AGNs with L-1.4 GHz %26gt; 10(23) W Hz(-1) are roughly five times more likely to have extremely broad [O iii] lambda 5007 lines (full width at half-maximum, FWHMAvg %26gt; 1000 km s(-1)) compared to lower L-1.4 GHz AGNs, and the width of the [O iii] lambda 5007 line peaks in moderate-radio-luminosity AGNs (L-1.4 GHz similar to 10(24) W Hz(-1)). Our results are consistent with the most disturbed gas kinematics being induced by compact radio cores (rather than powerful radio jets), although broadened [O iii] lambda 5007 lines are also present, but much rarer, in low-L-1.4 GHz systems. Our catalogue of multicomponent fits is freely available as an online resource for statistical studies of the kinematics and luminosities of the narrow- and broad-line AGN regions and the identification of potential targets for follow-up observations at ext-link-type=%26quot;uri%26quot; xlink:href=%26quot;http://sites.google.com/site/sdssalpaka%26quot; xmlns:xlink=%26quot;http://www.w3.org/1999/xlink%26quot;%26gt;http://sites.google.com/site/sdssalpaka.

• 出版日期2013-7
• 单位中国地震局