Spectroscopic observations of quasar outflows at rest-frame 500Å-1000Å have immense diagnostic power. We present analyses of such data, where absorption troughs from three important ions are measured: first, O iv/O iv* that allow us to obtain the distance of high ionization outflows from the AGN; second, Ne viiiand Mg x that are sensitive to the very high ionization phase of the outflow.Their inferred column densities, combined with those of troughs from O vi, N iv, and H i, yield two important results: 1) The outflow shows two ionization phases, where the high ionization phase carries the bulk of the material. This is similar to the situation seen in x-ray warm absorber studies. Furthermore, the low ionization phase is inferred to have a volume filling factor of 10 −5 − 10 −6 . 2) From the O iv*/O iv column density ratio, and the knowledge of the ionization parameter, we determine a distance of 3000 pc from the outflow to the central source. Since this is a typical high ionization outflow, we can determine robust values for the mass flux and kinetic luminosity of the outflow: 40 M ⊙ yr −1 and 10 45 ergs s −1 , respectively, where the latter is roughly equal to 1% of the bolometric luminosity.Such a large kinetic luminosity and mass flow rate measured in a typical high ionization wind suggests that quasar outflows are a major contributor to AGN feedback mechanisms.
We present the most energetic BALQSO outflow measured to date, with a kinetic luminosity of at least 10 46 erg s −1 , which is 5% of the bolometric luminosity of this high Eddington ratio quasar. The associated mass-flow rate is 400 solar masses per year. Such kinetic luminosity and mass-flow rate should provide strong active galactic nucleus feedback effects. The outflow is located at about 300 pc from the quasar and has a velocity of roughly 8000 km s −1 . Our distance and energetic measurements are based in large part on the identification and measurement of S iv and S iv* broad absorption lines (BALs). The use of this high-ionization species allows us to generalize the result to the majority of high-ionization BALQSOs that are identified by their C iv absorption. We also report the energetics of two other outflows seen in another object using the same technique. The distances of all three outflows from the central source (100-2000 pc) suggest that we observe BAL troughs much farther away from the central source than the assumed acceleration region of these outflows (0.01-0.1 pc).
We present new optical circular polarization measurements with typical uncertainties <0.1% for a sample of 21 quasars. All but two objects have null circular polarization. We use this result to constrain the polarization due to photon-pseudoscalar mixing along the line of sight. We detect significant (>3σ) circular polarization in two blazars with high linear polarization and discuss the implications of this result for quasar physics. In particular, the recorded polarization degrees may be indicative of magnetic fields as strong as 1 kG or a significant contribution of inverse Compton scattering to the optical continuum.
We present analysis of the UV spectrum of the low-z AGN IRAS F22456−5125 obtained with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. The spectrum reveals six main kinematic components, spanning a range of velocities of up to 800 km s −1 , which for the first time are observed in troughs associated with C ii, C iv, N v, Si ii, Si iii, Si iv, and S iv. We also obtain data on the O vi troughs, which we compare to those available from an earlier Far Ultraviolet Spectroscopic Explorer epoch. Column densities measured from these ions allow us to derive a well-constrained photoionization solution for each outflow component. Two of these kinematic components show troughs associated with transitions from excited states of Si ii and C ii. The number density inferred from these troughs, in combination with the deduced ionization parameter, allows us to determine the distance to these outflow components from the central source. We find these components to be at a distance of ∼10 kpc. The distances and the number densities derived are consistent with the outflow being part of a galactic wind.
We present medium-resolution (λ/Δλ ∼ 20 000) ultraviolet spectra covering the 1155−1760 Å spectral range of the Seyfert 1 galaxy Mrk 509 obtained using the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST). Our observations were obtained simultaneously with a Low Energy Transmission Grating Spectrometer observation using the Chandra X-ray Observatory, and they are part of a multiwavelength campaign in September through December 2009 which also included observations with XMM-Newton, Swift, and INTEGRAL. Our spectra are the highest signal-to-noise observations to date of the intrinsic absorption components seen in numerous prior ultraviolet observations. To take advantage of the high S/N, we describe special calibrations for wavelength, flat-field and line-spread function corrections that we applied to the COS data. We detect additional complexity in the absorption troughs compared to prior observations made with the Space Telescope Imaging Spectrograph (STIS) on HST. We attribute the UV absorption to a variety of sources in Mrk 509, including an outflow from the active nucleus, the interstellar medium and halo of the host galaxy, and possible infalling clouds or stripped gaseous material from a merger that are illuminated by the ionizing radiation of the active nucleus. Variability between the STIS and COS observation of the most blue-shifted component (#1) allows us to set an upper limit on its distance of <250 pc. Similarly, variability of component 6 between FUSE observations limits its distance to <1.5 kpc. The absorption lines in all components only partially cover the emission from the active nucleus with covering fractions that are lower than those seen in the prior STIS observations and are comparable to those seen in spectra from the Far Ultraviolet Spectroscopic Explorer (FUSE). Given the larger apertures of COS and FUSE compared to STIS, we favor scattered light from an extended region near the active nucleus as the explanation for the partial covering. As observed in prior X-ray and UV spectra, the UV absorption has velocities comparable to the X-ray absorption, but the bulk of the ultraviolet absorption is in a lower ionization state with lower total column density than the gas responsible for the X-ray absorption. We conclude that the outflow from the active nucleus is a multiphase wind.
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