Galactic-scale Absorption Outflow in the Low-luminosity Quasar IRAS F042505718: Hubble Space Telescope/Cosmic Origins Spectrograph Observations (original) (raw)
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A high-velocity narrow absorption line outflow in the quasar J212329.46 − 005052.9
Monthly Notices of the Royal Astronomical Society, 2010
We report on the discovery of a high-velocity narrow absorption line outflow in the redshift 2.3 quasar J212329.46-005052.9. Five distinct outflow systems are detected with velocity shifts from −9710 to −14,050 km s −1 and C iv λλ1548,1551 line widths of FWHM ≈ 62 to 164 km s −1 . This outflow is remarkable for having high speeds and a degree of ionization similar to broad absorption line (BAL) flows, but line widths roughly 100 times narrower than BALs and no apparent X-ray absorption. This is also, to our knowledge, the highest-velocity narrow absorption line system confirmed to be in a quasar outflow by all three indicators of line variability, smooth super-thermal line profiles and doublet ratios that require partial covering of the quasar continuum source. All five systems have stronger absorption in O vi λλ1032,1038 than C iv with no lower ionization metal lines detected. Their line variabilities also appear coordinated, with each system showing larger changes in C iv than O vi and line strength variations accompanied by nearly commensurate changes in the absorber covering fractions. The metallicity is approximately twice solar.
A Census of Intrinsic Narrow Absorption Lines in the Spectra of Quasars at z = 2–4
The Astrophysical Journal Supplement Series, 2007
We use Keck/HIRES spectra of 37 optically bright quasars at z = 2-4 to study narrow absorption lines that are intrinsic to the quasars (intrinsic NALs, produced in gas that is physically associated with the quasar central engine). We identify 150 NAL systems, that contain 124 C IV, 12 N V, and 50 Si IV doublets, of which 18 are associated systems (within 5,000 km s −1 of the quasar redshift). We use partial coverage analysis to separate intrinsic NALs from NALs produced in cosmologically intervening structures. We find 39 candidate intrinsic systems, (28 reliable determinations and 11 that are possibly intrinsic). We estimate that 10-17% of C IV systems at blueshifts of 5,000-70,000 km s −1 relative to quasars are intrinsic. At least 32% of quasars contain one or more intrinsic C IV NALs. Considering N V and Si IV doublets showing partial coverage as well, at least 50% of quasars host intrinsic NALs. This result constrains the solid angle subtended by the absorbers to the background source(s). We identify two families of intrinsic NAL systems, those with strong N V absorption, and those with negligible absorption in N V, but with partial coverage in the C IV doublet. We discuss the idea that these two families represent different regions or conditions in accretion disk winds. Of the 26 intrinsic C IV NAL systems, 13 have detectable low-ionization absorption lines at similar velocities, suggesting that these are two-phase structures in the wind rather than absorbers in the host galaxy. We also compare possible models for quasar outflows, including radiatively accelerated disk-driven winds, magnetocentrifugally accelerated winds, and pressure-driven winds, and we discuss ways of distinguishing between these models observationally.
High velocity outflows in narrow absorption line quasars
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 from 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 D(alpha_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 D(alpha_ox) suggest absorption in the UV band. The positive values of D(alpha_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.
Unsaturated Low-Ionization Broad Absorption Lines in the Quasar SDSS J144842.45+042403.1
We present a detailed analysis of the exceptional low-ionization broad absorption line (LoBAL) quasar SDSS J144842.45+042403.1. The C iv absorption trough, which is likely saturated, has a box-shaped bottom at a flux level of 2% Y5% of the unabsorbed flux. A large fraction of at least 80% of the C iv and Fe ii emission-line fluxes are obliterated by the C iv broad absorption lines ( BALs), spanning 3000 km s À1 in velocity. This indicates that the outflow intercepts most of the lines of sight to the continuum source and the broad emission line region (BELR). Therefore, the BAL region (BALR) should be located outside the BELR, and its size is no less than that of the BELR. The Al iii and Mg ii BAL troughs, which are well resolved, are found to be unsaturated and to show the same velocity structures. Meanwhile, their velocities largely overlap that of the C iv BAL, indicating that the LoBALs and the HiBALs (high-ionization BALs) are closely associated and most likely produced from the same outflow. The column densities of the Mg + and Al 2+ ions in the outflow are measured. Results from an X-ray observation performed with Chandra suggest the presence of intrinsic X-ray absorption with a hydrogen column density of 10 22 Y10 23 cm À2 . The measured Mg + and Al 2+ column densities can be well reproduced in models with a dimensionless ionization parameter of log U > À1:5 and a total hydrogen column density of N H ¼ 2:8 ; 10 22 U cm À2 . A comparison of models with the observed properties also suggests that the outflow is either very highly ionized (with a high column density) or clumpy.
Metal-Enriched Outflows in the Ultraluminous Infrared Quasar Q1321+058
Quasar outflows may play important role in the evolution of its host galaxy and central black hole, and are most often studied in absorption lines. In this paper, we present a detailed study of multiple outflows in the obscured ultraluminous infrared quasar Q1321+058. The outflows reveal themselves in the complex optical and ultraviolet (UV) emission-line spectrum, with a broad component blueshifted by 1650 km s −1 and a narrow component by 360 km s −1 , respectively. The higher velocity component shows ever strong N iii] (N iii]/C iii] = 3.8 ± 0.3 and N iii]/C iv = 0.53) and strong Si iii] (Si iii]/C iii] 1), in addition to strong [O iii]λ5007 and [Ne iii]λ3869 emission. A comparison of these line ratios with photoionization models suggests an overabundance of N and Si relative to C. The abundance pattern is consistent with a fast chemical enriching process associated with a recent starburst, triggered by a recent galaxy merger. The outflow extends to several tens to hundred parsecs from the quasar, and covers only a very small sky. We find that the outflow with line emitting gas is energetically insufficient to remove the interstellar medium of the host galaxy, but total kinetic energy may be much larger than suggested by the emission lines. The velocity range and the column density suggest that the outflow might be part of the low-ionization broad absorption line region as seen in a small class of quasars. The optical and UV continuum is starlight dominated and can be modeled with a young-aged (1 Myr) plus an intermediate-aged (∼0.5-1 Gyr) stellar populations, suggesting a fast building of the stellar mass in the host galaxy, consistent with the starburst-type metal abundances inferred from the high-velocity outflow spectrum.
Discovery of an Ultraviolet Counterpart to an Ultrafast X-Ray Outflow in the Quasar PG 1211+143
The Astrophysical Journal, 2018
We observed the quasar PG 1211+143 using the Cosmic Origins Spectrograph on the Hubble Space Telescope in 2015 April as part of a joint campaign with the Chandra X-ray Observatory and the Jansky Very Large Array. Our ultraviolet spectra cover the wavelength range 912-2100 Å. We find a broad absorption feature (∼ 1080 {km} {{{s}}}-1) at an observed wavelength of 1240 Å. Interpreting this as H I Lyα, in the rest frame of PG 1211+143 (z = 0.0809), this corresponds to an outflow velocity of -16,980 {km} {{{s}}}-1 (outflow redshift {z}{out}∼ -0.0551), matching the moderate ionization X-ray absorption system detected in our Chandra observation and reported previously by Pounds et al. With a minimum H I column density of {log} {N}{{H}{{I}}}> 14.5, and no absorption in other UV resonance lines, this Lyα absorber is consistent with arising in the same ultrafast outflow as the X-ray absorbing gas. The Lyα feature is weak or absent in archival ultraviolet spectra of PG 1211+143, strongly suggesting that this absorption is transient, and intrinsic to PG 1211+143. Such a simultaneous detection in two independent wavebands for the first time gives strong confirmation of the reality of an ultrafast outflow in an active galactic nucleus.
The Astrophysical Journal, 2019
We present the spectral analysis of Chandra/High Energy Transmission Grating Spectrometer (HETGS) and NuSTAR observations of the quasar PDS 456 from 2015, and XMM-Newton and NuSTAR archival data from 2013 to 2014, together with Chandra/HETGS data from 2003. We analyzed these three different epochs in a consistent way, looking for absorption features corresponding to highly ionized blueshifted absorption lines from H-like and He-like ions of iron (and nickel), as well as of other elements (O, Ne, Si, and S) in the soft band. We confirm the presence of a persistent ultra-fast outflow (UFO) with a velocity of v out = -0.24 to -0.29 c, that has previously been detected. We also report the detection of an additional faster component of the UFO with a relativistic velocity of v out = -0.48 c. We implemented photoionization modeling, using XSTAR analytic model warmabs, to characterize the physical properties of the different kinematic components of the UFO and of the partially covering absorber detected in PDS 456. These two relativistic components of the UFO observed in the three epochs analyzed in this paper are powerful enough to impact the host galaxy of PDS 456 through feedback from active galactic nuclei.
The Astrophysical Journal, 2014
We present the first observation of a galaxy (z = 0.2) that exhibits metal-line absorption back-illuminated by the galaxy ("down-the-barrel") and transversely by a background quasar at a projected distance of 58 kpc. Both absorption systems, traced by Mg II, are blueshifted relative to the galaxy systemic velocity. The quasar sight-line, which resides almost directly along the projected minor axis of the galaxy, probes Mg I and Mg II absorption obtained from Keck/LRIS and Ly α, Si II and Si III absorption obtained from HST/COS. For the first time, we combine two independent models used to quantify the outflow properties for down-the-barrel and transverse absorption. We find that the modeled down-the-barrel deprojected outflow velocities range between V dtb = 45 − 255 km s −1 . The transverse bi-conical outflow model, assuming constant-velocity flows perpendicular to the disk, requires wind velocities V out f low = 40 − 80 km s −1 to reproduce the transverse Mg II absorption kinematics, which is consistent with the range of V dtb . The galaxy has a metallicity, derived from Hα and N II, of [O/H]=−0.21±0.08, whereas the transverse absorption has [X/H] = −1.12 ± 0.02. The galaxy star-formation rate is constrained between 4.6-15 M ⊙ yr −1 while the estimated outflow rate ranges between 1.6-4.2 M ⊙ yr −1 and yields a wind loading factor ranging between 0.1 − 0.9. The galaxy and gas metallicities, the galaxy-quasar sight-line geometry, and the down-the-barrel and transverse modeled outflow velocities collectively suggest that the transverse gas originates from ongoing outflowing material from the galaxy. The ∼1 dex decrease in metallicity from the base of the outflow to the outer halo suggests metal dilution of the gas by the time it reached 58 kpc.
The extremely high velocity outflow in quasar PG0935+417
Monthly Notices of the Royal Astronomical Society, 2010
We report the detection of O VI λλ1031, 1037 and N V λλ1238, 1242 absorption in a system of 'mini-broad' absorption lines (mini-BALs) previously reported to have variable C IV λλ1548, 1550 in the quasar PG0935+417. The formation of these lines in an extremely high velocity outflow (with v ∼ −50 000 km s −1) is confirmed by the line variability, broad smooth absorption profiles and partial covering of the background light source. H I and lower-ionization metals are not clearly present. The line profiles are complex and asymmetric, with full widths at half-minimum (FWHM) of different components in the range ∼660 to ∼2510 km s −1. The resolved O VI doublet indicates that these lines are moderately saturated, with the absorber covering ∼80 per cent of the quasar continuum source (C f ∼ 0.8). We derive ionic column densities of the order of 10 15 cm −2 in C IV and several times larger in O VI, indicating an ionization parameter of log U −0.5. Assuming solar abundances, we estimate a total column density of N H ∼ 5 × 10 19 cm −2. Comparisons to data in the literature show that this outflow emerged sometime between 1982 when it was clearly not present and 1993 when it was first detected. Our examination of the C IV data from 1993 to 2007 shows that there is variable complex absorption across a range of velocities from −45 000 to −54 000 km s −1. There is no clear evidence for acceleration or deceleration of the outflow gas. The observed line variations are consistent with either changes in the ionization state of the gas or clouds crossing our lines of sight to the continuum source. In the former case, the recombination times constrain the location of outflow to be at a radial distance of r 1.2 kpc with density of n H 1.1 × 10 4 cm −3. In the latter case, the nominal transit times of moving clouds indicate r 0.9 pc. Outflows are common in active galactic nuclei (AGN), but extreme speeds such as those reported here are extremely rare. It is not clear what properties of PG 0935+417 might produce this unusual outflow. The quasar is exceptionally luminous, with L ∼ 6 × 10 47 erg s −1 , but it has just a modest Eddington ratio, L/L Edd ∼ 0.2, and no apparent unusual properties compared to other quasars. In fact, PG 0935+417 has significantly less X-ray absorption than typical BAL quasars even though its outflow has a degree of ionization typical of BALs at speeds that are 2-3 times larger than most BALs. These results present a challenge to theoretical models that invoke strong radiative shielding in the X-rays/far-UV to moderate the outflow ionization and thus enable its radiative acceleration to high speeds.
Deceleration of C iv and Si iv Broad Absorption Lines in X-Ray Bright Quasar SDSS-J092345+512710
The Astrophysical Journal, 2019
We report a synchronized kinematic shift of C iv and Si iv broad absorption lines (BAL) in a highionization, radio-loud, and X-ray bright quasar SDSS-J092345+512710 (at z em ∼ 2.1627). This quasar shows two broad absorption components (blue component at v ∼ 14, 000 km s −1 , and red component at v ∼ 4, 000 km s −1 with respect to the quasars systemic redshift). The absorption profiles of C iv and Si iv BAL of the blue component show decrease in outflow velocity with an average deceleration rate of −1.62 +0.04 −0.05 cm s −2 and −1.14 +0.21 −0.22 cm s −2 over a rest-frame time-span of 4.15 years. We do not see any acceleration-like signature in the red component. This is consistent with dramatic variabilities usually seen at high velocities. During our monitoring period the quasar has shown no strong continuum variability. We suggest the observed variability could be related to the time dependent changes in disk wind parameters like launching radius, initial flow velocity or mass outflow rate.