The prevalence and energetics of quasar feedback is a major unresolved problem in galaxy formation theory. In this paper, we present Gemini Integral Field Unit observations of ionized gas around eleven luminous, obscured, radio-quiet quasars at z ∼ 0.5 out to ∼ 15 kpc from the quasar; specifically, we measure the kinematics and morphology of [O iii]λ5007Å emission. The round morphologies of the nebulae and the large line-of-sight velocity widths (with velocities containing 80% of the emission as high as 10 3 km s −1 ) combined with relatively small velocity difference across them (from 90 to 520 km s −1 ) point toward wide-angle quasi-spherical outflows. We use the observed velocity widths to estimate a median outflow velocity of 760 km s −1 , similar to or above the escape velocities from the host galaxies. The line-of-sight velocity dispersion declines slightly toward outer parts of the nebulae (by 3% per kpc on average). The majority of nebulae show blueshifted excesses in their line profiles across most of their extents, signifying gas outflows. For the median outflow velocity, we finḋ E kin between 4 × 10 44 and 3 × 10 45 erg s −1 andṀ between 2 × 10 3 and 2 × 10 4 M ⊙ yr −1 . These values are large enough for the observed quasar winds to have a significant impact on their host galaxies. The median rate of converting bolometric luminosity to kinetic energy of ionized gas clouds is ∼2%. We report four new candidates for "super-bubbles" -outflows that may have broken out of the denser regions of the host galaxy.

Single-epoch virial black hole (BH) mass estimators utilizing broad emission lines have been routinely applied to high-redshift quasars to estimate their BH masses. Depending on the redshift, different line estimators (Hα, Hβ, Mg ii λ2798, C iv λ1549) are often used with optical/near-infrared spectroscopy. Here, we use a homogeneous sample of 60 intermediate-redshift (z ∼ 1.5-2.2) Sloan Digital Sky Survey quasars with optical and near-infrared spectra covering C iv through Hα to investigate the consistency between different single-epoch virial BH mass estimators. We critically compare rest-frame UV line estimators (C iv λ1549, C iii] λ1908, and Mg ii λ2798) with optical estimators (Hβ and Hα) in terms of correlations between line widths and between continuum/line luminosities, for the high-luminosity regime (L 5100 > 10 45.4 erg s −1 ) probed by our sample. The continuum luminosities of L 1350 and L 3000 , and the broad-line luminosities are well correlated with L 5100 , reflecting the homogeneity of quasar spectra in the rest-frame UV-optical, among which L 1350 and the line luminosities for C iv and C iii] have the largest scatter in the correlation with L 5100 . We found that the Mg ii FWHM correlates well with the FWHMs of the Balmer lines and that the Mg ii line estimator can be calibrated to yield consistent virial mass estimates with those based on the Hβ/Hα estimators, thus extending earlier results on less luminous objects. The C iv FWHM is poorly correlated with the Balmer line FWHMs, and the scatter between the C iv and Hβ FWHMs consists of an irreducible part (∼0.12 dex), and a part that correlates with the blueshift of the C iv centroid relative to that of Hβ, similar to earlier studies comparing C iv with Mg ii. The C iii] FWHM is found to correlate with the C iv FWHM, and hence is also poorly correlated with the Hβ FWHM. While the C iv and C iii] lines can be calibrated to yield consistent virial mass estimates as Hβ on average, the scatter is substantially larger than Mg ii, and the usage of C iv/C iii] FWHM in the mass estimators does not improve the agreement with the Hβ estimator. We discuss controversial claims in the literature on the correlation between C iv and Hβ FWHMs, and suggest that the reported correlation is either a result based on small samples or only valid for low-luminosity objects.

We present a study of the mass-metallicity (M − Z) relation and H II region physical conditions in a sample of 20 star-forming galaxies at 1.0 < z < 1.5 drawn from the DEEP2 Galaxy Redshift Survey. We find a correlation between stellar mass and gas-phase oxygen abundance in the sample and compare it with the one observed among UV-selected z ∼ 2 star-forming galaxies and local objects from the Sloan Digital Sky Survey (SDSS). This comparison, based on the same empirical abundance indicator, demonstrates that the zero point of the M − Z relationship evolves with redshift, in the sense that galaxies at fixed stellar mass become more metal-rich at lower redshift. Measurements of [O III]/Hβ and [N II]/Hα emission-line ratios show that, on average, objects in the DEEP2 1.0 < z < 1.5 sample are significantly offset from the excitation sequence observed in nearby H II regions and SDSS emission-line galaxies. In order to fully understand the causes of this offset, which is also observed in z ∼ 2 star-forming galaxies, we examine in detail the small fraction of SDSS galaxies that have similar diagnostic ratios to those of the DEEP2 sample. Some of these galaxies indicate evidence for AGN and/or shock activity, which may give rise to their unusual line ratios and contribute to Balmer emission lines at the level of ∼ 20%. Others indicate no evidence for AGN or shock excitation yet are characterized by higher electron densities and temperatures, and therefore interstellar gas pressures, than typical SDSS star-forming galaxies of similar stellar mass. These anomalous objects also have higher concentrations and star formation rate surface densities, which are directly connected to higher interstellar pressure. Higher star formation rate surface densities, interstellar pressures, and H II region ionization parameters may also be common at high redshift. These effects must be taken into account when using strong-line indicators to understand the evolution of heavy elements in galaxies. When such effects are included, the inferred evolution of the M − Z relation out to z ∼ 2 is more significant than previous estimates.

Black hole feedback -the strong interaction between the energy output of supermassive black holes and their surrounding environments -is routinely invoked to explain the absence of overly luminous galaxies, the black hole vs. bulge correlations and the similarity of black hole accretion and star formation histories. Yet direct probes of this process in action are scarce and limited to small samples of active nuclei. In this paper we present Gemini Integral Field Unit observations of the distribution of ionized gas around luminous, obscured, radio-quiet quasars at z ∼ 0.5. We detect extended ionized gas nebulae via [O iii]λ5007Å emission in every case, with a mean diameter of 28 kpc. These nebulae are nearly perfectly

We present a sample of 167 type 2 AGNs with double-peaked [O III] λλ4959,5007 narrow emission lines, selected from the Seventh Data Release of the Sloan Digital Sky Survey. The double-peaked profiles can be well modeled by two velocity components, blueshifted and redshifted from the systemic velocity. Half of these objects have a more prominent redshifted component. In cases where the Hβ emission line is strong, it also shows two velocity components whose line-of-sight (LOS) velocity offsets are consistent with those of [O III]. The relative LOS velocity offset between the two components is typically a few hundred km s −1 , larger by a factor of ∼ 1.5 than the line full width at half maximum of each component. The offset correlates with the host stellar velocity dispersion σ * . The host galaxies of this sample show systematically larger σ * , stellar masses, and concentrations, and older luminosity-weighted mean stellar ages than a regular type 2 AGN sample matched in redshift, [O III] λ5007 equivalent width and luminosity; they show no significant difference in radio properties. These double-peaked features could be due to narrow-line region kinematics, or binary black holes. The statistical properties do not show strong preference for or against either scenario, and spatially resolved optical imaging, spectroscopy, radio or X-ray followup are needed to draw firm conclusions.