We present results from an observation of the gravitationally lensed z=1.51 narrow absorption line AGN HS 0810+2554 performed with the Chandra X-ray Observatory. The factor of ~100 lensing magnification of HS 0810+2554 makes this source exceptionally
bright. Absorption lines are detected at rest-frame energies of ~ 7.7 keV and ~11.0 keV at >97% significance. By interpreting these lines to arise from highly ionized iron the implied outflow velocities of the X-ray absorbing gas corresponding to these lines are 0.13c and 0.41c, respectively. The presence of these relativistic outflows and the absence of any significant low-energy X-ray absorption suggest that a shielding gas is not required for the generation of the relativistic X-ray absorbing winds in HS 0810+2554. UV spectroscopic observations with VLT/UVES indicate that the UV absorbing material is outflowing at v_UV ~0.065c. Our analysis indicates that the fraction of the total bolometric energy released by HS 0810+2554 into the IGM in the form of kinetic energy is epsilon_k = 1.0(-0.6,+0.8). An efficiency of greater than unity implies that magnetic driving is likely a significant contributor to the acceleration of this X-ray absorbing wind. We also estimate the mass-outflow rate of the strongest absorption component to be Mdot_abs=1.1(-0.7,+0.9) M_solar yr^-1. Assuming that the energetic outflow detected in the NAL AGN HS 0810+2554 is a common property of most AGN it would suggest that the X-ray absorbing wind may have a larger opening angle than previously thought. This has important consequences for estimating the feedback contribution of X-ray absorbing winds to the surrounding IGM.
A significant fraction of the sub-damped Lyman-alpha (sub-DLA) absorption systems in quasar spectra appear to be metal-rich, many with even super-solar element abundances. This raises the question whether some sub-DLAs may harbor active galactic nucl
ei (AGN) since supersolar metallicities are observed in AGN. Here we investigate this question based on a mini-survey of 21 quasars known to contain sub-DLAs in their spectra. The X-ray observations were performed with the Chandra X-ray Observatory. In cases of no detection we estimated upper limits of the X-ray luminosities of possible AGNs at the redshifts of the sub-DLAs. In six cases we find possible X-ray emission within ~ 1 arcsec of the background quasar consistent with the presence of a nearby X-ray source. If these nearby X-ray sources are at the redshifts of the sub-DLAs, their estimated 0.2-10 keV luminosities range between 0.8 x 10^{44}h^{-2} and 4.2 x 10^{44}h^{-2} erg s^{-1}, thus ruling out a normal late-type galaxy origin, and suggesting that the emission originates in a galactic nucleus near the center of a protogalaxy. The projected distances of these possible nearby X-ray sources from the background quasars lie in the range of 3-7 h^{-1} kpc, consistent with our hypothesis that they represent AGNs centered on the sub-DLAs. Deeper follow-up X-ray and optical observations are required to confirm the marginal detections of X-rays from these sub-DLA galaxies.
We present results from monitoring observations of the gravitationally lensed quasar RX J1131-1231 performed with the Chandra X-ray Observatory. The X-ray observations were planned with relatively long exposures that allowed a search for energy-depen
dent microlensing in the soft (0.2-2 keV) and hard (2-10 keV) light curves of the images of RX J1131-1231. We detect significant microlensing in the X-ray light-curves of images A and D, and energy-dependent microlensing of image D. The magnification of the soft band appears to be larger than that in the hard band by a factor of ~ 1.3 when image D becomes more magnified. This can be explained by the difference between a compact, softer-spectrum corona that is producing a more extended, harder spectrum reflection component off the disk. This is supported by the evolution of the fluorescent iron line in image D over three consecutive time-averaged phases of the light curve. In the first period, a Fe line at E = 6.36(-0.16,+0.13) keV is detected (at > 99% confidence). In the second period, two Fe lines are detected, one at E = 5.47(-0.08,+0.06) keV (detected at > 99% confidence) and another at E = 6.02(-0.07,+0.09) keV (marginally detected at > 90% confidence), and in the third period, a broadened Fe line at 6.42(-0.15,+0.19) keV is detected (at > 99% confidence). This evolution of the Fe line profile during the microlensing event is consistent with the line distortion expected when a caustic passes over the inner disk where the shape of the fluorescent Fe line is distorted by General Relativistic and Doppler effects.
The current paradigm for the AGN phenomenon is a central engine that consists of an inflow of material accreting in the form of a disk onto a supermassive black hole. Observations in the UV and optical find high velocity ionized material outflowing f
rom the black hole. We present results from Suzaku and XMM-Newton observations of a sample of intrinsic NAL quasars with high velocity outflows. Our derived values of the intrinsic column densities of the X-ray absorbers are consistent with an outflow scenario in which NAL quasars are viewed at smaller inclination angles than BAL quasars. We find that the distributions of alpha_ox and Dalpha_ox of the NAL quasars of our sample differ significantly from those of BAL quasars and SDSS radio-quiet quasars. The NAL quasars are not significantly absorbed in the X-ray band and the positive values of Dalpha_ox suggest absorption in the UV band. The positive values of Dalpha_ox of the intrinsic NAL quasars can be explained in a geometric scenario where our lines of sight towards the compact X-ray hot coronae of NAL quasars do not traverse the absorbing wind whereas lines of sight towards their UV emitting accretion disks do intercept the outflowing absorbers.
We present results from a monitoring campaign performed with the Chandra X-ray Observatory of the gravitationally lensed quasars RX J1131-1231 and HE 1104-1805. We detect significant X-ray variability in all images of both quasars. The flux variabili
ty detected in image A of RX J1131-1231 is of particular interest because of its high amplitude (a factor of ~ 20). We interpret it as arising from microlensing since the variability is uncorrelated with that of the other images and the X-ray flux ratios show larger changes than the optical as we would expect for microlensing of the more compact X-ray emission regions. The differences between the X-ray and optical flux ratios of HE 1104-1805 are less dramatic, but there is no significant soft X-ray or dust absorption, implying the presence of X-ray microlensing in this system as well. Combining the X-ray data with the optical light curves we find that the X-ray emitting region of HE 1104-1805 is compact with a half-light radius ~ 6 r_g, where the gravitational radius is r_g = 3.6 x 10^14 cm, thus placing significant constraints on AGN corona models. We also find that the microlensing in HE 1104-1805 favors mass models for the lens galaxy that are dominated by dark matter. Finally, we better characterize the massive foreground cluster near RX J1131-1231, set limits on other sources of extended X-ray emission, and limit the fluxes of any central odd images to be 30-50 (3 sigma) times fainter than the observed images.
