arXiv subjects

Doyee Byun

Publications and source records attributed to Doyee Byun.

At least 19 recordsLinked to original sources

arXiv2026

X-ray Flaring and Variability in NGC 1275, the Heart of the Perseus Cluster

NGC 1275 is the central galaxy in the Perseus Cluster. The active galactic nucleus (AGN) within NGC 1275 is notable for its strong and variable radio activity, tied to the production of radio jets that inflate large bubbles in the hot intracluster medium (ICM). High spatial resolution X-ray imaging can separate the AGN from the bright ICM, but monitoring the mass accretion rate onto the black hole and establishing disk-jet connections in NGC 1275 requires a high cadence. Here, we report on X-ray monitoring of NGC 1275 using data taken over 20 years with the Neil Gehrels Swift Observatory. Modeling the temporally constant ICM in each observation allows X-ray emission from accretion onto the black hole to be traced reliably, with typical flux errors of $\sim 3\%$. X-ray flaring by a factor of $\sim2$ over mere days is detected starting on MJD 59956 (2023 Feb. 21). The flares imply an emission region consistent with $r \leq 870~(10^{8}~M_{\odot}/M_{BH})~ GM/c^{2}$. The profile of the flaring is inconsistent with simple predictions for tidal disruption events. A flare appears roughly 300 days later in radio monitoring data at 43 GHz. Overall, our results indicate that coordinated, moderate-resolution X-ray imaging and radio monitoring could potentially trace disk-jet connections in the AGN that most vividly impact large-scale structure, and be extended to other sources that impact their hosts.

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arXiv2026

XRISM Spectroscopy of Variable Accretion-driven Disk Winds in NGC 4151: When, Where, and How Fast Outflows are Launched

X-ray observations probe the inner accretion flow within active galactic nuclei, revealing the highest gas column densities and fastest winds. The most diverse winds yet revealed with the Resolve calorimeter spectrometer aboard XRISM are found in NGC~4151, a nearby Seyfert-1 AGN that may qualify as a ``changing-look'' source (CLAGN). Herein, we report on wind variability in 14 XRISM observations of NGC~4151, summing to 0.9~Ms of exposure over a period of 395 days. We examined the dependence of key wind parameters on hardness and intensity selections, and as a function of time relative to flaring and dip events. The results suggest a globally organized but locally complex wind structure. Slow ``warm absorber'' components (WAs; $v_{\rm{out}} \sim 100-1000~\rm{km~s^{-1}}$) are always observed and likely represent failed winds at radius of $10^4 - 10^5 GM/c^2$, within the inner wall of the torus. In contrast, ``very fast'' and ``ultra-fast'' outflows (VFOs and UFOs; $v_{\rm{out}} \sim 10^3-10^4~\rm{km~s^{-1}}$, $v_{\rm{out}} \sim 0.033-0.33~c$) are strongest 10~ks after the peak of flares, and during periods with low flux. Ten kiloseconds is among the shortest flare--wind response timescales reported in an AGN, suggesting that the winds are observed close to the launching site. The absorption measure distribution (AMD) and the large outflow momentum rates suggest that the high-velocity flows visible in the Fe~K band are magnetically driven, while locally clumpy, likely owing to radiation pressure; one or both of these mechanisms may be enhanced following a flare and most visible during low-flux windows.

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arXiv2026

Dissecting the Nuclear Structure of NGC 5548 with XRISM. I. Physical Properties of the Highly Ionized Outflows

We present a detailed spectral analysis of an X-Ray Imaging and Spectroscopy Mission (XRISM) observation of the prototypical Seyfert 1 galaxy NGC 5548. XRISM's Resolve microcalorimeter reveals, for the first time, highly ionized outflows in this active galactic nucleus (AGN) through the detection of Fe XXV and Fe XXVI absorption lines in the Fe K band. Modeling the XRISM/Resolve spectrum alongside XMM-Newton Reflection Grating Spectrometer (RGS) data allows us to probe the ionization and kinematic structure of the outflows in this AGN. We identify four distinct ionization components, with ionization parameters log $\xi$ ranging from 0.9 to 3.4. Three of these components are further resolved into two velocity sub-components, demonstrating the multiphase structure of the outflows. The measured outflow velocities span 240 to 2730 km/s. We find a trend of increasing column density with ionization parameter ($\xi$), along with a general pattern of increasing outflow velocity with $\xi$. The XRISM/Resolve spectrum provides a far more detailed absorption measure distribution (AMD) than was previously possible, revealing two distinct slopes above and below $\log\xi \sim 2.6$. A comparison of the Fe XXV absorption line profile with UV absorption lines (C IV and Ly$\alpha$) observed with the Hubble Space Telescope reveals both overlaps and deviations. The XRISM/Resolve results suggest a multiphase, clumpy outflow in NGC 5548, consistent with a "hybrid wind" scenario in which the observed parameter trends arise from multiple origins and driving mechanisms.

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arXiv2026

Reverberation in the Narrow Fe K${\alpha}$ Line in the Seyfert Galaxy NGC 4151 with XRISM

Emission lines that "echo" variations in the ionizing flux produced close to black holes are powerful probes of the central engine. In the Seyfert-1.5 galaxy NGC 4151, high-resolution X-ray spectra and time lags in low-resolution X-ray data suggest that part of the narrow Fe K$_{\alpha}$ line originates close to the optical broad line region (BLR). We report on a sequence of nine XRISM observations of NGC 4151, obtained every other day in 2024. Swift monitoring was undertaken to sample the driving flux before, during, and after the XRISM sequence. Using suitable line kernels, we measure a mean BLR component width of $\sigma = 5.36\pm 0.48\times 10^{3}~{\rm km}~ {\rm s}^{-1}$. Modeling the Swift continuum and XRISM line flux trends gives a lag of $\tau = 3.5^{+2.8}_{-1.7}$ days ($r=3.6^{+3.0}_{-1.7}\times 10^{3}~GM/c^{2}$ for $M_{BH} = 1.7\times 10^{7}~M_{\odot}$), significant at the $2\sigma$ level via Monte Carlo simulations, and consistent with prior measurements and direct spectral fits. This lag implies a black hole mass of $M_{BH}/f_{X} = 2.0^{+1.4}_{-1.0}\times 10^{7} M_{\odot}$, where $f_{X}$ is a geometrical factor. A standard optical value for this factor gives a mass that is nominally higher than typical H$\beta$ mass estimates, but formally consistent. Our results suggest that XRISM can measure lags and black hole masses in both unobscured and obscured AGN.

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arXiv2026

The 0.9 Megasecond XRISM/Resolve Spectrum of the Seyfert-1 AGN NGC 4151

NGC 4151 is the brightest Seyfert-1 active galaxy in the pass band of the Resolve calorimeter spectrometer aboard XRISM. It has been observed on 14 occasions, resulting in a total exposure of 893 ks. Herein, we report on an analysis of the time-averaged spectrum. The narrow Fe K$_{\alpha}$ emission line complex requires contributions from the torus and the optical broad line region (BLR). Models assuming an emissivity index of $q=2$ for these components are statistically preferred over models assuming $q=3$ for a flat disk (where $J\propto r^{-q}$). A smooth shoulder on the red wing of these line components is likely best interpreted as Compton scattering in a medium with bound electrons, potentially signaling the presence of dust at the base of the BLR and in the torus. The data statistically prefer the addition of relativistic reflection from the innermost accretion disk, extending down to a radius of $r = 3.2^{+3.5}_{-2.0}~GM/c^{2}$ and with an inclination of $\theta = 29.7^{+0.5}_{-0.4}$ degrees. The Fe K edge at 7.1 keV is best modeled with contributions from multiple charge states, consistent with obscuration due to cool, $kT \simeq 5$ eV collisional gas or photoionized gas. Dust is not evident in the Fe K absorption edge. A spectrum of outflows is clearly revealed, with slow ``warm absorber'' winds spanning Fe XX-XXVI, fast winds primarily seen via Fe XXV and Fe XXVI lines, and ultra-fast outflows (or, UFOs) seen as broad Fe~XXVI lines. The warm absorbers are almost certainly ``failed'' winds that return to the central engine; the data constrain their radius, density, filling factor, and distribution. For the most conservative volume filling factors, the UFOs may not deliver the kinetic feedback needed to halt star formation, on average. However, they may generate galaxy-altering feedback for larger filling factors and/or during certain intervals. (abridged)

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arXiv2025

Multi-layered Fast Wind observed in XMM-Newton snapshot of Seyfert 1 Markarian 877

Ultra Fast Outflows (UFOs) are powerful, highly ionized winds launched from the innermost regions of Active Galactic Nuclei (AGNs), reaching velocities of 0.03 -- 0.3 c and playing a key role in AGN feedback. We present a photoionization analysis of an 18 ks \xmm\ snapshot of the Seyfert 1 AGN Mrk 877, revealing three distinct UFO components with line-of-sight velocities of $0.10^{+0.005}_{-0.005}~c$ , $ 0.04^{+0.005}_{-0.004}~c$ , and $0.05^{+0.005}_{-0.004}~c$. These components span a broad range of ionization parameters and column densities, producing absorption features across both soft and hard X-ray bands. Even under the most conservative assumption for the volume filling factor, the fastest component exceeds $5\%$ of the Eddington luminosity, making it capable of driving strong galaxy-scale feedback. The soft X-ray UFO component, despite its lower ionization, shares a similar velocity as a higher-ionization component, hinting at a two-phase medium likely shaped by clumpiness or interactions with ambient material. The density profile inferred from the Absorption Measurement Distributions (AMD) and the positive trend between outflow momentum rate and radiation momentum flux suggest that wind is powered by a combination of radiative and magnetic driving.

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arXiv2025

XRISM/Resolve Spectroscopy of the Central Engine in the Seyfert-1 AGN Mrk 279

High-resolution X-ray spectroscopy with XRISM gives an unprecedented view of the ``central engine'' in active galactic nuclei, providing unique insights into black hole accretion and feedback. We present an analysis of the first XRISM/Resolve spectrum of the Seyfert-1 galaxy Mrk 279, known for its complex line profiles and variability. The data reveal velocity components within the Fe K$_{\alpha}$ emission line that can be associated with the inner face of the molecular torus ($r \geq 10^{4}~GM/c^{2})$, the broad line region (BLR; $r = 1650^{+5780}_{-1480}~GM/c^{2}$), and the inner accretion disk ($r = 81^{+280}_{-75}~GM/c^{2}$). We find evidence of low-velocity, highly ionized gas that contributes an H-like Fe XXVI emission line at 6.97 keV, confirming suggestions from prior low-resolution spectra. The data do not show slow winds in absorption, but two pairs of lines - consistent with He-like and H-like Fe shifted by $v\simeq 0.22c$ and $v\simeq 0.33c$ - improve the fit, and could represent an ultra-fast outflow (UFO). Their addition to the model only reduces the Akaike Information Criterion by 3.6 and 3.5, respectively, signaling modest support. Additional observations are needed to definitively test for the presence of fast X-ray winds in Mrk 279. We discuss these results in the context of the geometry of the central engine in AGN, emerging trends in XRISM studies of AGN, and the nature of the potential UFOs.

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arXiv2025

XRISM Spectroscopy of Accretion-Driven Wind Feedback in NGC 4151

The hottest, most ionized, and fastest winds driven by accretion onto massive black holes have the potential to reshape their host galaxies. Calorimeter-resolution X-ray spectroscopy is the ideal tool to understand this feedback mode, as it enables accurate estimates of physical characteristics needed to determine the wind's kinetic power. We report on a photoionization analysis of five observations of the Seyfert-1.5 galaxy NGC 4151, obtained with XRISM/Resolve in 2023 and 2024. In the Fe K band, individual spectra require as many as six wind absorption components. Slow "warm absorbers" (WAs, $v_{\mathrm{out}} \sim 100 - 1000~\mathrm{km~s^{-1}}$), very fast outflows (VFOs, $v_{\mathrm{out}} \sim 10^3~{\rm km}~{\rm s}^{-1} - 10^4~{\rm km}~{\rm s}^{-1}$), and ultra-fast outflows (UFOs, $v_{\mathrm{out}} \sim 10^4~{\rm km}~{\rm s}^{-1} - 10^5~{\rm km}~{\rm s}^{-1}$ or $0.033 - 0.33~c$) are detected simultaneously, and indicate a stratified, multiphase wind. Fast and variable emission components suggest that the wind is axially asymmetric. All of the wind components have mass flow rates comparable to or in excess of the mass accretion rate, though the slowest zones may be "failed" winds that do not escape. Two UFO components have kinetic luminosities that exceed the theoretical threshold of $L_{kin} \geq 0.5\% L_{Edd}$ necessary to strip the host bulge of gas and halt star formation, even after corrections for plausible filling factors. The bulk properties of the observed winds are consistent with magnetocentrifugal driving, where the density depends on radius as $n \propto r^{-1.5}$, but radiative driving and other mechanisms may also be important. Numerous complexities and variability require further analysis.

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arXiv2025

The distance of quasar outflows from the central source: The first consistent values from emission and absorption determinations

Measuring the distance of quasar outflows from the central source ($R$) is essential for determining their importance for AGN feedback. There are two methods to measure $R$: 1) A direct determination using spatially resolved Integral Field Spectroscopy (IFS) of the outflow in emission. 2) An indirect method which uses the absorption troughs from ionic excited states. The column density ratio between the excited and resonance states yields the outflow number density. Combined with a knowledge of the outflow's ionization parameter, $R$ can be determined. Generally, the IFS method probes $R$ range of several kpc or more, while the absorption method usually yields $R$ values of less than 1 kpc. There is no inconsistency between the two methods as the determinations come from different objects. Here we report the results of applying both methods to the same quasar outflow, where we derive consistent determinations of $R$ $\approx$ 5 kpc. This is the first time where the indirect absorption $R$ determination is verified by a direct spatially resolved IFS observation. In addition, the velocities (and energetics) from the IFS and absorption data are also found to be consistent. Therefore, these are two manifestations of the same outflow. In this paper we concentrate on the absorption $R$ determination for the outflow seen in quasar 3C 191 using VLT/X-shooter observations. We also reanalyze an older absorption determination for the outflow based on Keck/HIRES data and find that revised measurement to be consistent with ours. Our companion paper details the IFS analysis of the same object.

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arXiv2024

Physical characterization of the FeLoBAL outflow in SDSS J0932+0840: Analysis of VLT/UVES observations

Context: The study of quasar outflows is essential in understanding the connection between active galactic nuclei (AGN) and their host galaxies. We analyze the VLT/UVES spectrum of quasar SDSS J0932+0840 and identify several narrow and broad outflow components in absorption, with multiple ionization species including Fe II, which puts it among a rare class of outflows known as FeLoBALs. Aims: We study one of the outflow components to determine its physical characteristics by determining the total hydrogen column density, ionization parameter and the hydrogen number density. Through these parameters, we aim to obtain the distance of the outflow from the central source, its mass outflow rate and kinetic luminosity, and to constrain the contribution of the outflow to AGN feedback. Methods: We obtain the ionic column densities from the absorption troughs in the spectrum, and use photoionization modeling to extract the physical parameters of the outflow, including the total hydrogen column density and ionization parameter. The relative population of the observed excited states of Fe II is used to model the hydrogen number density of the outflow. Results: We use the Fe II excited states to model the electron number density ($n_e$) and hydrogen number density ($n_H$) independently and obtain $n_e$ $\simeq$ $10^{3.4}$ cm$^{-3}$ and $n_H$ $\simeq$ $10^{4.8}$ cm$^{-3}$. Our analysis of the physical structure of the cloud shows that these two results are consistent with each other. This places the outflow system at a distance of $0.7_{-0.4}^{+0.9}$ kpc from the central source, with mass flow rate ($\dot{M}$) of $43^{+65}_{-26}$ $M_\odot$ yr$^{-1}$ and kinetic luminosity ($\dot{E_k}$) of $0.7^{+1.1}_{-0.4}$ $\times$ $10^{43}$ erg s$^{-1}$.

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arXiv2024

Determining the absolute chemical abundance of nitrogen and sulfur in the quasar outflow of 3C298

Context. Quasar outflows are key players in the feedback processes that influence the evolution of galaxies and the intergalactic medium. The chemical abundance of these outflows provides crucial insights into their origin and impact. Aims. To determine the absolute abundances of nitrogen and sulfur and the physical conditions of the outflow seen in quasar 3C298. Methods. We analyze archival spectral data from the Hubble Space Telescope (HST) for 3C298. We measure Ionic column densities from the absorption troughs and compare the results to photoionization predictions made by the Cloudy code for three different spectral energy distributions (SED), including MF87, UVsoft, and HE0238 SEDs. We also calculate the ionic column densities of excited and ground states of N iii to estimate the electron number density and location of the outflow using the Chianti atomic database. Results. The MF87, UVsoft, and HE0238 SEDs yield nitrogen and sulfur abundances at super-solar, solar, and sub-solar values, respectively, with a spread of 0.4 to 3 times solar. Additionally, we determined an electron number density of log(ne) greater than 3.3 cm-3, with the outflow possibly extending up to a maximum distance of 2.8 kpc. Conclusions. Our results indicate solar metallicity within a 60 percent uncertainty range, driven by variations in the chosen SED and photoionization models. This study underscores the importance of SEDs impact on determining chemical abundances in quasars outflows. These findings highlight the necessity of considering a wider range of possible abundances, spanning from sub solar to super solar values.

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arXiv2024

AGN STORM 2: VIII. Investigating the Narrow Absorption Lines in Mrk 817 Using HST-COS Observations

We observed the Seyfert 1 galaxy Mrk817 during an intensive multi-wavelength reverberation mapping campaign for 16 months. Here, we examine the behavior of narrow UV absorption lines seen in HST/COS spectra, both during the campaign and in other epochs extending over 14 years. We conclude that while the narrow absorption outflow system (at -3750 km/s with FWHM=177 km/s) responds to the variations of the UV continuum as modified by the X-ray obscurer, its total column density (logNH =19.5 cm-2) did not change across all epochs. The adjusted ionization parameter (scaled with respect to the variations in the Hydrogen ionizing continuum flux) is log UH =-1.0. The outflow is located at a distance smaller than 38 parsecs from the central source, which implies a hydrogen density of nH > 3000 cm-3. The absorption outflow system only covers the continuum emission source and not the broad emission line region, which suggests that its transverse size is small (< 1e16 cm), with potential cloud geometries ranging from spherical to elongated along the line of sight.

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arXiv2024

Extreme FeLoBAL Outflow in the VLT/UVES Spectrum of Quasar SDSS J1321-0041

Context. Quasar outflows are often analyzed to determine their ability to contribute to active galactic nucleus (AGN) feedback. We identified a broad absorption line (BAL) outflow in the VLT/UVES spectrum of the quasar SDSS J1321-0041. The outflow shows troughs from Fe II, and is thus categorized as an FeLoBAL. This outflow is unusual among the population of FeLoBAL outflows, as it displays C II and Si II BALs. Aims. Outflow systems require a kinetic luminosity above $\sim0.5\%$ of the quasar's luminosity to contribute to AGN feedback. For this reason, we analyzed the spectrum of J1321-0041 to determine the outflow's kinetic luminosity, as well as the quasar's bolometric luminosity. Methods. We measured the ionic column densities from the absorption troughs in the spectrum and determined the Hydrogen column density and ionization parameter using those column densities as our constraints. We also determined the electron number density, $n_e$, based on the ratios between the excited-state and resonance-state column densities of Fe II and Si II. This allowed us to find the distance of the outflow from its central source, as well as its kinetic luminosity. Results. We determined the kinetic luminosity of the outflow to be $8.4^{+13.7}_{-5.4}\times 10^{45}\text{ erg s}^{-1}$, and the quasar's bolometric luminosity to be $1.72\pm0.13\times10^{47}\text{ erg s}^{-1}$, resulting in a ratio of $\dot{E}_k/L_{Bol}=4.8^{+8.0}_{-3.1}\%$. We conclude that this outflow has a sufficiently high kinetic luminosity to contribute to AGN feedback.

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arXiv2024

BAL Outflow in Quasar B0254-3327B: Analysis and Comparison with Other Extreme UV Outflows

We have identified a broad absorption line (BAL) outflow in the HST/STIS spectrum of the quasar QSO B0254-3327B at velocity $v=-3200\text{ km s$^{-1}$}$. The outflow has absorption troughs from ions such as Ne VIII, Na IX, Si XII, and Ne V. We also report the first detection of S XIV absorption troughs, implying very high ionization. Via measurement of the ionic column densities, photoionization analysis, and determination of the electron number density of the outflow, we found the kinetic luminosity of the outflow system to be up to $\sim1\%$ of the quasar's Eddington luminosity, or $\sim5\%$ of the bolometric luminosity, making it a potential contributor to AGN feedback. A solution with two ionization phases was needed, as a single phase was not sufficient to satisfy the constraints from the measured ionic column densities. We find that the ionization parameter of the very high-ionization phase of the outflow is within the expected range of an X-ray warm absorber. We also examined the physical properties of the outflow of Q0254-334 along with previously studied extreme UV outflows, with a total sample of 24 outflow systems, finding a weak negative correlation between outflow velocity and distance from the central source, with larger distances corresponding to slower velocities. The very high-ionization phase of the Q0254-334 outflow has one of the highest ionization parameters of UV absorption outflows to date, which we attribute to the presence of S XIV.

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arXiv2023

Narrow absorption line Outflow in Seyfert 1 galaxy J1429+4518: Outflow's distance from the central source and its energetics

In the HST/COS spectrum of the Seyfert 1 galaxy 2MASX J14292507+4518318, we have identified a narrow absorption line (NAL) outflow system with a velocity of -151 km s$^{-1}$ This outflow exhibits absorption troughs from the resonance states of ions like CIV, NV, SiIV, and SiII, as well as excited states from CII*, and SiII*. Our investigation of the outflow involved measuring ionic column densities and conducting photoionization analysis. These yield the total column density of the outflow to be estimated as $\log N_{H}$=19.84 [cm$^{-2}]$, its ionization parameter to be $\log U_{H}$=$-$2.0 and its electron number density equal to $\log n_{e}$= 2.75[cm$^{-3}$]. These measurements enabled us to determine the mass-loss rate and the kinetic luminosity of the outflow system to be $Mdot$=0.22[$M_{Sun}$$yr^{-1}$] and $\log Edot_{K}$=39.3 [erg s$^{-1}$], respectively. We have also measured the location of the outflow system to be at $\sim$275 pc from the central source. This outflow does not contribute to the AGN feedback processes due to the low ratio of the outflow's kinetic luminosity to the AGN's Eddington luminosity ($Edot_{K}/L_{Edd}\approx 0.00025 \%$). This outflow is remarkably similar to the two bipolar lobe outflows observed in the Milky Way by XMM-Newton and Chandra.

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arXiv2023

AGN STORM 2. III. A NICER view of the variable X-ray obscurer in Mrk 817

The AGN STORM 2 collaboration targeted the Seyfert 1 galaxy Mrk 817 for a year-long multiwavelength, coordinated reverberation mapping campaign including HST, Swift, XMM-Newton, NICER, and ground-based observatories. Early observations with NICER and XMM revealed an X-ray state ten times fainter than historical observations, consistent with the presence of a new dust-free, ionized obscurer. The following analysis of NICER spectra attributes variability in the observed X-ray flux to changes in both the column density of the obscurer by at least one order of magnitude ($N_\mathrm{H}$ ranges from $2.85\substack{+0.48\\ -0.33} \times 10^{22}\text{ cm}^{-2}$ to $25.6\substack{+3.0\\ -3.5} \times 10^{22} \text{ cm}^{-2}$) and the intrinsic continuum brightness (the unobscured flux ranges from $10^{-11.8}$ to $10^{-10.5}$ erg s$^{-1}$ cm$^{-2}$ ). While the X-ray flux generally remains in a faint state, there is one large flare during which Mrk 817 returns to its historical mean flux. The obscuring gas is still present at lower column density during the flare but it also becomes highly ionized, increasing its transparency. Correlation between the column density of the X-ray obscurer and the strength of UV broad absorption lines suggests that the X-ray and UV continua are both affected by the same obscuration, consistent with a clumpy disk wind launched from the inner broad line region.

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arXiv2022

High Mass Flow Rate in a BAL Outflow of Quasar SDSS J1130+0411

We present the analysis of the absorption troughs of six outflows observed in quasar SDSS J1130+0411 ($z \approx 3.98$) with radial velocities ranging from $-2400$ to $-15,400$ km s$^{-1}$. These spectra were taken with the Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph over the rest frame wavelength range of $1135-1890$ Å. In the main outflow system ($v \approx -3200$ km s$^{-1}$), we identify Fe II and several Fe II* absorption troughs as well as Si II and Si II* troughs, which we use to determine the electron number density $\log n_e = 2.6_{-0.7}^{+0.8}$ cm$^{-3}$. Using the column densities of these and other ions, we determine a photoionization solution with hydrogen column density $\log N_H = 21.44_{-0.33}^{+0.24}$ cm$^{-2}$ and ionization parameter $\log U_H = -1.75_{-0.45}^{+0.28}$. From these values we derive the distance $R = 16_{-11}^{+23}$ kpc, the average mass flow rate $\dot{M} = 4100_{-2400}^{+6600}$ $M_{\odot}$ yr$^{-1}$, and the kinetic luminosity $\log \dot{E}_k = 46.13_{-0.37}^{+0.41}$ erg s$^{-1}$. This $\dot{E}_k$ is $1.4_{-0.8}^{+2.2}$% of the quasar's Eddington luminosity, and therefore contributes significantly to AGN feedback.

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arXiv2022

VLT/UVES Observation of the SDSS J2357-0048 Outflow

We found a broad absorption line (BAL) outflow in the VLT/UVES spectrum of the quasar SDSS J235702.54-004824.0, in which we identified four subcomponents. We measured the column densities of the ions in one of the subcomponents ($v$ = -1600 km s$^{-1}$), which include O I and Fe II. We found the kinetic luminosity of this component to be at most ~2.4% of the quasar's Eddington luminosity. This is near the amount required to contribute to AGN feedback. We also examined the time-variability of a C IV mini-BAL found at $v$ = -8700 km s$^{-1}$, which shows a shallower and narrower absorption feature attached to it in previous SDSS observations from 2000 and 2001, but not in the spectra from 2005 and onwards.

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