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We perform a systematic study of outflow in the narrow-line region (NLR) of active galactic nuclei (AGNs) at z ∼ 0.4–0.8 based upon a large sample of ∼900 quasars at z ∼ 0.4–0.8. The sample is extracted from the Sloan Digital Sky Survey by mainly requiring that (1) the g-band magnitude is brighter than 19 mag and (2) the [O iii]λ5007 emission line has a signal-to-noise ratio larger than 30. Profiles of multiple emission lines are modeled by a sum of several Gaussian functions. The spectral analysis allows us to identify (1) a prevalence of both [O iii]λ5007 line blue asymmetry and bulk velocity blueshift of both [Ne iii]λ3869 and [Ne iii]λ3426 lines, when the [O ii]λ3727 line is used as a reference. The velocity offset of the [O iii]λ5007 line is, however, distributed around a value of zero, except for a few outliers. (2) Not only the significant [O iii]λ5007 line asymmetry, but also the large bulk velocity offsets of [Ne iii]λ3869 and [Ne v]λ3426 emission lines tend to occur in the objects with high L/LEdd, which is considerably consistent with the conclusions based on local AGNs. With three MBH estimation methods, the significance level of the trend is found to be better than 2.9σ, 3.2σ, and 1.8σ for [O iii], [Ne iii], and [Ne v], respectively. After excluding the role of radio jets, the revealed dependence of NLR gas outflow on L/LEdd allows us to argue that the pressure caused by the wind/radiation launched/emitted from a central supermassive black hole is the most likely origin of the outflow in these distant quasars, which implies that the outflow in luminous AGNs up to z ∼ 1 have the same origin. [ABSTRACT FROM AUTHOR]

We investigate the relationship between the emission line and the 3000 Å continuum variations using a sample of 68 intermediate-redshift () broad-line quasars spanning a bolometric luminosity range of 44.49 erg erg s−1 (Eddington ratio from ∼0.026 to 0.862). This sample is constructed from SDSS-DR7Q and BOSS-DR12Q, each with at least two spectroscopic epochs in SDSS-I/II/III surveys. In addition, we adopt the following signal-to-noise ratio (S/N) selection criteria: (a) for and the 3000 Å continuum, S/N 10; and (b) for narrow lines, S/N 5. All our quasar spectra are recalibrated based on the assumption of constant narrow emission-line fluxes. In an analysis of spectrum-to-spectrum variations, we find a fairly close correlation (Spearman ) between the variations in broad and in the continuum. This is consistent with the idea that is varying in response to the continuum emission variations. Adopting the modified weighted least squares regression method, we statistically constrain the slopes (i.e., the responsivity α of the broad ) between the variations in both components for the sources in different luminosity bins after eliminating intrinsic biases introduced by the rescaling process itself. It is shown that the responsivity is quite small (average ) and anti-correlates with the quasar luminosity. Our results indicate that high signal-to-noise flux measurements are required to robustly detect the intrinsic variability and the time lag of the line. [ABSTRACT FROM AUTHOR]

We present the results of recent Chandra, XMM-Newton, and Hubble Space Telescope observations of the radio-loud (RL), broad absorption line (BAL) quasar PG 1004+130. We compare our new observations to archival X-ray and UV data, creating the most comprehensive, high signal-to-noise, multi-epoch, spectral monitoring campaign of a RL BAL quasar to date. We probe for variability of the X-ray absorption, the UV BAL, and the X-ray jet, on month–year timescales. The X-ray absorber has a low column density of when it is assumed to be fully covering the X-ray emitting region, and its properties do not vary significantly between the four observations. This suggests that the observed absorption is not related to the typical “shielding gas” commonly invoked in BAL quasar models, but is likely due to material further from the central black hole. In contrast, the C iv BAL shows strong variability. The equivalent width (EW) in 2014 is , showing a fractional increase of from the 2003 observation, 3183 days earlier in the rest-frame. This places PG 1004+130 among the most highly variable BAL quasars. By combining Chandra observations we create an exposure that is 2.5 times deeper than studied previously, with which to investigate the nature of the X-ray jet and extended diffuse X-ray emission. An X-ray knot, likely with a synchrotron origin, is detected in the radio jet (30 kpc) from the central X-ray source with a spatial extent of (15 kpc). No similar X-ray counterpart to the counterjet is detected. Asymmetric, non-thermal diffuse X-ray emission, likely due to inverse Compton scattering of Cosmic Microwave Background photons, is also detected. [ABSTRACT FROM AUTHOR]

We report the discovery of a candidate active galactic nucleus (AGN), 2XMM J123103.2+110648 at z = 0.13, with an X-ray spectrum represented purely by soft thermal emission reminiscent of Galactic black hole (BH) binaries in the disk-dominated state. This object was found in the second XMM-Newton serendipitous source catalog as a highly variable X-ray source. In three separate observations, its X-ray spectrum can be represented either by a multicolor disk blackbody model with an inner temperature of kTin ≈ 0.16-0.21 keV or a Wien spectrum Comptonized by an optically thick plasma with kT ≈ 0.14-0.18 keV. The soft X-ray luminosity in the 0.5-2 keV band is estimated to be (1.6-3.8) × 1042 erg s–1. Hard emission above ∼2 keV is not detected. The ratio of the soft to hard emission is the strongest among AGNs observed thus far. Spectra selected in high/low-flux time intervals are examined in order to study spectral variability. In the second observation with the highest signal-to-noise ratio, the low-energy (below 0.7 keV) spectral regime flattens when the flux is high, while the shape of the high-energy part (1-1.7 keV) remains unchanged. This behavior is qualitatively consistent with being caused by strong Comptonization. Both the strong soft excess and spectral change consistent with Comptonization in the X-ray spectrum imply that the Eddington ratio is large, which requires a small BH mass (smaller than ∼105M☼). [ABSTRACT FROM AUTHOR]