Using a sample of 24264 optically selected AGNs from the SDSS DR7 database, we characterise how the profile of the [O III]λ5007 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 kpcscale line emitting gas. Firstly, we use spectral stacking to characterise how the average [O III]λ5007 profile changes as 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]λ5007 profile, with AGNs of moderate radio luminosity (L 1.4 GHz = 10 23 − 10 25 W Hz −1 ) having the broadest [O III]λ5007 profiles. Conversely, we find only a modest change in the [O III]λ5007 profile with increasing radio loudness and find no significant difference between the [O III]λ5007 profiles of broad and narrow-line Seyfert 1s. Similarly, only the very highest Eddington ratio AGNs (i.e., > 0.3) show any signs of having broadened [O III]λ5007 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]λ5007 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 "blue-wing", which we interpret as evidence of outflowing ionised gas. We perform multi-component fitting to the Hβ, [O III]λλ4959, 5007, [N II]λλ6548, 6584 and Hα lines for all the AGNs in our sample to calculate the proportions of AGNs with broad [O III]λ5007 profiles. The individual fits confirm the results from our stacked spectra; AGNs with L 1.4 GHz > 10 23 W Hz −1 are roughly 5 times more likely to have extremely broad [O III]λ5007 lines (FWHM Avg > 1000 km s −1 ) compared to lower L 1.4 GHz AGNs and the width of the [O III]λ5007 line peaks in moderate radio luminosity AGNs (L 1.4 GHz ∼ 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]λ5007 lines are also present, but much rarer, in low L 1.4 GHz systems. Our catalogue of multi-component 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.

We present a spectroscopic survey of almost 15,000 candidate intermediate-redshift Luminous Red Galaxies (LRGs) brighter than i=19.8, observed with 2dF on the Anglo-Australian Telescope. The targets were selected photometrically from the Sloan Digital Sky Survey (SDSS) and lie along two narrow equatorial strips covering 180 sq deg. Reliable redshifts were obtained for 92% of the targets and the selection is very efficient: over 90% have redshifts between 0.45 and 0.8. More than 80% of the ~11,000 red galaxies have pure absorption-line spectra consistent with a passively-evolving old stellar population. The redshift, photometric and spatial distributions of the LRGs are described. The 2SLAQ data will be released publicly from mid-2006, providing a powerful resource for observational cosmology and the study of galaxy evolution.Comment: Accepted for publication in MNRAS. 21 pages. The 2SLAQ LRG data discussed in this paper will become public when the paper appears in the journal. See http://www.2slaq.info for more information on the survey and data release, and a higher resolution version of the pape

We perform an extensive analysis of the C iv λ1549 line in three large spectroscopic surveys of quasars. Differing approaches for fitting the C iv line can be found in the literature, and we compare the most common methods to highlight the relative systematics associated with each. We choose the line‐fitting procedure that results in a symmetric profile for the C iv line and gives accurate fits to local emission features around the line, and use this approach to measure the width of the C iv line in spectra from the Sloan Digital Sky Survey (SDSS) and 2dF QSO Redshift (2QZ) and 2dF SDSS LRG And QSO (2SLAQ) surveys. The results are compared with a previous study of the Mg ii λ2799 line in the same sample. We find the C iv line tends to be broader than the Mg ii line in spectra that have both lines, and the average ratio between the lines is consistent with a simplistic model for a photoionized, virialized and stratified broad‐line region. There exists a statistically significant correlation between the widths of the C iv and Mg ii lines. However, the correlation is weak, and the scatter around a best fit is only marginally less than the full dynamic range of linewidths. Motivated by previous work on the Mg ii line, we examine the dispersion in the distribution of C iv linewidths. We find that the dispersion in C iv linewidths is essentially independent of both redshift and luminosity. This result is in stark contrast to the Mg ii line, which shows a strong luminosity dependence. Furthermore, we demonstrate that the low level of dispersion in C iv linewidth (∼0.08 dex) is inconsistent with a pure‐disc model for the emitting region and use our data to constrain simple models for the broad‐line region. Finally, we consider our results in terms of their implications for the virial technique for estimating black hole masses. The inconsistency between Mg ii and C iv linewidths in single spectra, combined with the differing behaviour of the Mg ii and C iv linewidth distributions as a whole, indicates that there must be an inconsistency between Mg ii and C iv virial mass estimators. Furthermore, the level of intrinsic dispersion in Mg ii and C iv linewidths contributes less dynamic range to virial mass estimates than the error associated with the estimates. The indication is that the linewidth term in these UV virial mass estimators may be essentially irrelevant with respect to the typical uncertainty on a mass estimate.

We present the final spectroscopic QSO catalogue from the 2dF-SDSS LRG (luminous red galaxy) and QSO (2SLAQ) survey. This is a deep, 18 < g < 21.85 (extinction corrected), sample aimed at probing in detail the faint end of the broad line active galactic nuclei luminosity distribution at z 2.6. The candidate QSOs were selected from SDSS photometry and observed spectroscopically with the 2dF spectrograph on the Anglo-Australian Telescope. This sample covers an area of 191.9 deg 2 and contains new spectra of 16 326 objects, of which 8764 are QSOs and 7623 are newly discovered [the remainder were previously identified by the 2dF QSO Redshift Survey (2QZ) and SDSS]. The full QSO sample (including objects previously observed in the SDSS and 2QZ surveys) contains 12 702 QSOs. The new 2SLAQ spectroscopic data set also contains 2343 Galactic stars, including 362 white dwarfs, and 2924 narrow emission-line galaxies with a median redshift of z = 0.22.We present detailed completeness estimates for the survey, based on modelling of QSO colours, including host-galaxy contributions. This calculation shows that at g 21.85 QSO colours are significantly affected by the presence of a host galaxy up to redshift z ∼ 1 in the SDSS ugriz bands. In particular, we see a significant reddening of the objects in g − i towards the fainter g-band magnitudes. This reddening is consistent with the QSO host galaxies being dominated by a stellar population of age at least 2-3 Gyr.

The definitive version can be found at : http://onlinelibrary.wiley.com/ Copyright Wiley-BlackwellWe use the Sloan Digital Sky Survey, along with the NRAO VLA Sky Survey and the Westerbork Northern Sky Survey to define a sample of 746 radio-loud quasars and measure their 330 MHz-1.4 GHz spectral indexes. Following previous authors we take the radio spectral index as an indicator of the orientation towards the quasars such that more pole-on sources tend to have flatter spectral indexes. We use this proxy for the orientation of quasars to investigate the effect orientation may have on optical spectra. Quasars with flatter spectral indexes tend to be brighter. However, we find no indication of reddening in steep-spectrum quasi-stellar objects (QSOs) to indicate obscuration of the accretion disc by a torus as a possible explanation. Nor do we find increased reddening in the flat-spectrum sources which could imply a contribution from jet-related synchrotron emission. We reproduce a previously described anticorrelation between the width of the Mg ii line and radio spectral index that indicates a disc-like geometry for the Mg ii broad-line region (BLR). However, in contrast to previous authors we find no such correlation for the C iv line suggesting a more isotropic high-ionization BLR. Both the [O ii] and [O iii] narrow lines have more flux in steep spectrum sources, while the [O iii]/[O ii] flux ratio is lower in these sources. To describe both of these effects we propose a simple geometric model in which the narrow-line region (NLR) exists primarily on the surface of optically thick clouds facing the active nucleus and the NLR is stratified such that higher ionization lines are found preferentially closer to the nucleus. Quantitatively we find that orientation may effect the observed strength of narrow lines, as well as ratios between lines, by a factor of similar to 2. These findings have implications for the use of [O iii] and [O ii] emission lines to estimate bolometric luminosities, as well as comparisons between narrow-line luminosity functions for type 1 and 2 objects and the potential of emission-line diagnostic diagrams as an accurate tool with which to distinguish types of active galactic nuclei. Finally we find no evidence that broad-absorption line (BAL) QSOs have a different spectral index distribution to non-BALs although we only have 25 obvious BALs in our sample