Search for: All records

We have identified a broad absorption line (BAL) outflow in the HST/STIS spectrum of the quasar QSO B0254-3327B at velocity v = −3200 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 ∼1 per cent of the quasar’s Eddington luminosity, or ∼5 per cent 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.

 

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 $\sim 2.4{{\ \rm per\ cent}}$ of the quasar’s Eddington luminosity. This is near the amount required to contribute to active galactic nucleus 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 to 2001, but not in the spectra from 2005 and onwards.

 

We present the analysis of the absorption troughs of six outflows observed in quasar SDSS J1130 + 0411 ($z$ ≈ 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 ($v$ ≈ −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⊙ yr−1, and the kinetic luminosity $\log \dot{E}_k = 46.13_{-0.37}^{+0.41}$ erg s−1. This $\dot{E}_k$ is $1.4_{-0.8}^{+2.2}$ per cent of the quasar’s Eddington luminosity, and therefore contributes significantly to AGN feedback.

 

We analyse the VLT/UVES spectrum of the quasar SDSS J143907.5-010616.7, retrieved from the UVES Spectral Quasar Absorption Database. We identify two outflow systems in the spectrum: a mini broad absorption line (mini-BAL) system and a narrow absorption line (NAL) system. We measure the ionic column densities of the mini-BAL ($v$ = −1550 km s−1) outflow, which has excited state absorption troughs of ${\rm Fe\, \rm {\small {ii}}}$. We determine that the electron number density $\log {n_e}=3.4^{+0.1}_{-0.1}$, based on the ratios between the excited and ground state abundances of ${\rm Fe\, \rm {\small {ii}}}$, and find the kinetic luminosity of the outflow to be ${\lesssim}0.1\,\hbox{per cent}$ of the quasar’s Eddington luminosity, making it insufficient to contribute to AGN feedback.

 

We analyze Very Large Telescope/UVES observations of the quasar SDSS J024221.87+004912.6. We identify four absorption outflow systems: a Civbroad absorption line (BAL) atv≈ −18,000 km s⁻¹and three narrower low-ionization systems with centroid velocities ranging from –1200 to –3500 km s⁻¹. These outflows show similar physical attributes to the [Oiii] outflows studied by Liu et al. (2013). We find that two of the systems are energetic enough to contribute to active galactic nucleus feedback, with one system reaching above 5% of the quasar’s Eddington luminosity. We also find that this system is at a distance of 67 kpc away from the quasar, the farthest detected mini-BAL absorption outflow from its central source to date. In addition, we examine the time-variability of the BAL and find that its velocity monotonically increases, while the trough itself becomes shallower over time.

 

Abstract The AGN STORM 2 Collaboration targeted the Seyfert 1 galaxy Mrk 817 for a year-long multiwavelength, coordinated reverberation mapping campaign including Hubble Space Telescope, Swift, XMM-Newton, NICER, and ground-based observatories. Early observations with NICER and XMM revealed an X-ray state 10 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 H ranges from 2.85 − 0.33 + 0.48 × 10 22 cm − 2 to 25.6 − 3.5 + 3.0 × 10 22 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. 

Abstract We present the first results from the ongoing, intensive, multiwavelength monitoring program of the luminous Seyfert 1 galaxy Mrk 817. While this active galactic nucleus was, in part, selected for its historically unobscured nature, we discovered that the X-ray spectrum is highly absorbed, and there are new blueshifted, broad, and narrow UV absorption lines, which suggest that a dust-free, ionized obscurer located at the inner broad-line region partially covers the central source. Despite the obscuration, we measure UV and optical continuum reverberation lags consistent with a centrally illuminated Shakura–Sunyaev thin accretion disk, and measure reverberation lags associated with the optical broad-line region, as expected. However, in the first 55 days of the campaign, when the obscuration was becoming most extreme, we observe a de-coupling of the UV continuum and the UV broad emission-line variability. The correlation recovered in the next 42 days of the campaign, as Mrk 817 entered a less obscured state. The short C iv and Ly α lags suggest that the accretion disk extends beyond the UV broad-line region.