I Zwicky 1 (hereafter I Zw 1) is the prototype optical narrow-line Seyfert 1 galaxy. It is also a nearby (z = 0.0611), luminous quasi-stellar object (QSO), accreting close to the Eddington limit. ...XMM-Newton observations of I Zw 1 in 2015 reveal the presence of a broad and blueshifted P Cygni iron K profile, as observed through a blueshifted absorption trough at 9 keV and a broad excess of emission at 7 keV in the X-ray spectra. The profile can be well fitted with a wide-angle accretion disk wind, with an outflow velocity of at least −0.25c. In this respect, I Zw 1 may be analogous to the prototype fast wind detected in the QSO PDS 456, while its overall mass outflow rate is scaled down by a factor of 50, due to its lower black hole mass. The mechanical power of the fast wind in I Zw 1 is constrained to within 5%-15% of Eddington, while its momentum rate is of the order unity. Upper limits placed on the energetics of any molecular outflow, from its CO profile measured by IRAM, appear to rule out the presence of a powerful, large-scale, energy-conserving wind in this active galactic nucleus (AGN). We consider whether I Zw 1 may be similar to a number of other AGNs, such as PDS 456, where the large-scale galactic outflow is much weaker than what is anticipated from models of energy-conserving feedback.
Past X-ray observations of the nearby luminous quasar PDS 456 (at z = 0.184) have revealed a wide-angle accretion disk wind with an outflow velocity of ∼−0.25c, as observed through observations of ...its blueshifted iron K-shell absorption line profile. Here we present three new XMM-Newton observations of PDS 456: one in 2018 September where the quasar was bright and featureless and two in 2019 September, 22 days apart, occurring when the quasar was five times fainter and where strong blueshifted lines from the wind were present. During the second 2019 September observation, three broad ( = 3000 km s−1) absorption lines were resolved in the high-resolution Reflection Grating Spectrometer spectrum that are identified with blueshifted O viii Ly , Ne ix He , and Ne x Ly . The outflow velocity of this soft X-ray absorber was found to be v/c = −0.258 0.003, fully consistent with an iron K absorber with v/c = −0.261 0.007. The ionization parameter and column density of the soft X-ray component (log = 3.4, NH = 2 × 1021 cm−2) outflow was lower by about 2 orders of magnitude when compared to the high-ionization wind at iron K (log = 5, NH = 7 × 1023 cm−2). Substantial variability was seen in the soft X-ray absorber between the 2019 observations, declining from NH = 1023 to 1021 cm−2 over 20 days, while the iron K component was remarkably stable. We conclude that the soft X-ray wind may originate from an inhomogeneous wind streamline passing across the line of sight that, due to its lower ionization, is located further from the black hole, on parsec scales, than the innermost disk wind.
ABSTRACT
Using the results of a previous X‐ray photoionization modelling of blueshifted Fe K absorption lines on a sample of 42 local radio‐quiet AGNs observed with XMM–Newton, in this Letter we ...estimate the location and energetics of the associated ultrafast outflows (UFOs). Due to significant uncertainties, we are essentially able to place only lower/upper limits. On average, their location is in the interval ∼0.0003–0.03 pc (∼ 102–104rs) from the central black hole, consistent with what is expected for accretion disc winds/outflows. The mass outflow rates are constrained between ∼0.01 and 1 M⊙ yr−1, corresponding to >rsim5–10 per cent of the accretion rates. The average lower/upper limits on the mechanical power are log 42.6–44.6 erg s−1. However, the minimum possible value of the ratio between the mechanical power and bolometric luminosity is constrained to be comparable or higher than the minimum required by simulations of feedback induced by winds/outflows. Therefore, this work demonstrates that UFOs are indeed capable to provide a significant contribution to the AGN cosmological feedback, in agreement with theoretical expectations and the recent observation of interactions between AGN outflows and the interstellar medium in several Seyfert galaxies.
The existence of ionized X-ray absorbing layers of gas along the line of sight to the nuclei
of Seyfert galaxies is a well established observational fact. This material is systematically
outflowing ...and shows a large range in parameters. However, its actual nature and dynamics
are still not clear. In order to gain insights into these important issues we performed a literature
search for papers reporting the parameters of the soft X-ray warm absorbers (WAs) in 35 type
1 Seyferts and compared their properties to those of the ultra-fast outflows (UFOs) detected in
the same sample. The fraction of sources with WAs is >60 per cent, consistent with previous
studies. The fraction of sources with UFOs is >34 per cent, >67 per cent of which also
show WAs. The large dynamic range obtained when considering all the absorbers together,
spanning several orders of magnitude in ionization, column, velocity and distance allows us,
for the first time, to investigate general relations among them. In particular, we find significant
correlations indicating that the closer the absorber is to the central black hole, the higher the
ionization, column, outflow velocity and consequently the mechanical power. In all the cases,
the absorbers continuously populate the whole parameter space, with the WAs and the UFOs
lying always at the two ends of the distribution. These evidence strongly suggest that these
absorbers, often considered of different types, could actually represent parts of a single large-scale
stratified outflow observed at different locations from the black hole. The UFOs are likely
launched from the inner accretion disc and the WAs at larger distances, such as the outer disc
and/or torus. We argue that the observed parameters and correlations are, to date, consistent
with both radiation pressure through Compton scattering and magnetohydrodynamic processes
contributing to the outflow acceleration, the latter playing a major role. Most of the absorbers,
especially the UFOs, show a sufficiently high mechanical power (at least approx 0.5 per cent of the
bolometric luminosity) to provide a significant contribution to active galactic nuclei (AGN)
feedback and thus to the evolution of the host galaxy. In this regard, we find possible evidence
for the interaction of the AGN wind with the surrounding environment on large scales.
Context.
Soft and hard X-ray excesses, compared to the continuum power-law shape between ∼2−10 keV, are common features observed in the spectra of active galactic nuclei (AGN) and are associated with ...the accretion disc-corona system around the supermassive black hole. However, the dominant process at work is still highly debated and has been proposed to be either relativistic reflection or Comptonisation. Such an investigation can be problematic for AGN that have significant intrinsic absorption, either cold or warm, which can severely distort the observed continuum. Therefore, AGN with no (or very weak) intrinsic absorption along the line-of-sight, called bare AGN, are the best targets for directly probing disc-corona systems.
Aims.
We aim to characterise the main X-ray spectral physical components from the bright bare broad-line Seyfert 1 AGN Mrk 110, as well as the physical process(es) at work in its disc-corona system viewed almost face-on.
Methods.
We perform the X-ray broadband spectral analysis thanks to two simultaneous
XMM-Newton
and
NuSTAR
observations performed on November 16−17, 2019, and April 5−6, 2020. We also use a deep
NuSTAR
observation obtained in January 2017 for the spectral analysis above 3 keV.
Results.
The broadband X-ray spectra of Mrk 110 are characterised by the presence of a prominent and absorption-free smooth soft X-ray excess, moderately broad O
VII
and Fe K
α
emission lines, and a lack of a strong Compton hump. The continuum above ∼3 keV is very similar at both epochs, while some variability (stronger when brighter) is present for the soft X-ray excess. A combination of soft and hard Comptonisation by a warm and hot corona, respectively, plus mildly relativistic disc reflection reproduce the broadband X-ray continuum very well. The inferred warm corona temperature,
k
T
warm
∼ 0.3 keV, is similar to the values found in other sub-Eddington AGN, whereas the hot corona temperature,
k
T
hot
∼ 21−31 keV (depending mainly on the assumed hot corona geometry), is found to be in the lower range of the values measured in AGN.
We have conducted a multiwavelength survey of 42 radio loud narrow-1ine Seyfert 1 galaxies (RLNLS1s), selected by searching among all the known sources of this type and omitting those with steep ...radio spectra. We analyse data from radio frequencies to X-rays, and supplement these with information available from online catalogues and the literature in order to cover the full electromagnetic spectrum. This is the largest known multiwavelength survey for this type of source. We detected 90% of the sources in X-rays and found 17% at γ rays. Extreme variability at high energies was also found, down to timescales as short as hours. In some sources, dramatic spectral and flux changes suggest interplay between a relativistic jet and the accretion disk. The estimated masses of the central black holes are in the range ~106−8 M⊙, lower than those of blazars, while the accretion luminosities span a range from ~0.01 to ~0.49 times the Eddington limit, with an outlier at 0.003, similar to those of quasars. The distribution of the calculated jet power spans a range from ~1042.6 to ~1045.6 erg s-1, generally lower than quasars and BL Lac objects, but partially overlapping with the latter. Once normalised by the mass of the central black holes, the jet power of the three types of active galactic nuclei are consistent with each other, indicating that the jets are similar and the observational differences are due to scaling factors. Despite the observational differences, the central engine of RLNLS1s is apparently quite similar to that of blazars. The historical difficulties in finding radio-loud narrow-line Seyfert 1 galaxies might be due to their low power and to intermittent jetactivity.
We present a detailed analysis of a recent, 2013 Suzaku campaign on the nearby (z = 0.184) luminous (L
bol ∼ 1047 erg s−1) quasar PDS 456. This consisted of three observations, covering a total ...duration of ∼1 Ms and a net exposure of 455 ks. During these observations, the X-ray flux was unusually low, suppressed by a factor of >10 in the soft X-ray band when compared to previous observations. We investigated the broad-band continuum by constructing a spectral energy distribution (SED), making use of the optical/UV photometry and hard X-ray spectra from the later simultaneous XMM–Newton and NuSTAR campaign in 2014. The high-energy part of this low-flux SED cannot be accounted for by physically self-consistent accretion disc and corona models without attenuation by absorbing gas, which partially covers a substantial fraction of the line of sight towards the X-ray continuum. At least two layers of absorbing gas are required, of column density log (N
H,low/cm−2) = 22.3 ± 0.1 and log (N
H,high/cm−2) = 23.2 ± 0.1, with average line-of-sight covering factors of ∼80 per cent (with typical ∼5 per cent variations) and 60 per cent (±10–15 per cent), respectively. During these observations PDS 456 displays significant short-term X-ray spectral variability, on time-scales of ∼100 ks, which can be accounted for by variable covering of the absorbing gas along the line of sight. The partial covering absorber prefers an outflow velocity of
$v_{\rm pc} = 0.25^{+0.01}_{-0.05}\,c$
at the >99.9 per cent confidence level over the case where v
pc = 0. This is consistent with the velocity of the highly ionized outflow responsible for the blueshifted iron K absorption profile. We therefore suggest that the partial covering clouds could be the denser, or clumpy part of an inhomogeneous accretion disc wind. Finally estimates are placed upon the size-scale of the X-ray emission region from the source variability. The radial extent of the X-ray emitter is found to be of the order ∼15–20R
g, although the hard X-ray (>2 keV) emission may originate from a more compact or patchy corona of hot electrons, which is typically ∼6–8R
g in size.
Past X-ray observations of the nearby luminous quasar PDS 456 (at z = 0.184) have revealed a wide angle accretion disk wind, with an outflow velocity of ∼−0.25c. Here, we unveil a new, relativistic ...component of the wind through hard X-ray observations with NuSTAR and XMM-Newton, obtained in 2017 March when the quasar was in a low-flux state. This very fast wind component, with an outflow velocity of −0.46 0.02c, is detected in the iron K band, in addition to the −0.25c wind zone. The relativistic component may arise from the innermost disk wind, launched from close to the black hole at a radius of ∼10 gravitational radii. The opacity of the fast wind also increases during a possible obscuration event lasting for 50 ks. We suggest that the very fast wind may only be apparent during the lowest X-ray flux states of PDS 456, becoming overly ionized as the luminosity increases. Overall, the total wind power may even approach the Eddington value.
The evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and ...radiation-driven winds can transfer most of this energy back to the host galaxy. Over five different epochs, we detected the signatures of a nearly spherical stream of highly ionized gas in the broadband x-ray spectra of the luminous quasar PDS 456. This persistent wind is expelled at relativistic speeds from the inner accretion disk, and its wide aperture suggests an effective coupling with the ambient gas. The outflow's kinetic power larger than 1046 ergs per second is enough to provide the feedback required by models of black hole and host galaxy coevolution.
Ongoing studies with XMM–Newton have shown that powerful accretion disc winds, as revealed through highly ionized Fe K-shell absorption at E ≥ 6.7 keV, are present in a significant fraction of active ...galactic nuclei (AGNs) in the local Universe (Tombesi et al. 2010a). In Gofford et al., we analysed a sample of 51 Suzaku-observed AGNs and independently detected Fe K absorption in ∼40 per cent of the sample, and we measured the properties of the absorbing gas. In this work, we build upon these results to consider the properties of the associated wind. On average, the fast winds (v
w > 0.01c) are located 〈r〉 ∼ 1015−18 cm (typically ∼102−4 r
s) from their black hole, their mass outflow rates are of the order of
$\langle \skew{3}\dot{M}_{\rm w}\rangle \sim 0.01\hbox{--}1$
M⊙ yr−1 or
${\sim }(0.01\hbox{--}1)\skew{3}\dot{M}_{\rm Edd}$
and kinetic power is constrained to 〈L
w〉 ∼ 1043−45 erg s−1, equivalent to ∼(0.1–10 per cent)L
Edd. We find a fundamental correlation between the source bolometric luminosity and the wind velocity, with
$v_{\rm w} \propto L_{\rm bol}^{\alpha }$
and
$\alpha =0.4^{+0.3}_{-0.2}$
(90 per cent confidence), which indicates that more luminous AGN tend to harbour faster Fe K winds. The mass outflow rate
$\skew{3}\dot{M}_{\rm w}$
, kinetic power L
w and momentum flux
$\dot{p}_{\rm w}$
of the winds are also consequently correlated with L
bol, such that more massive and more energetic winds are present in more luminous AGN. We investigate these properties in the framework of a continuum-driven wind, showing that the observed relationships are broadly consistent with a wind being accelerated by continuum-scattering. We find that, globally, a significant fraction (∼85 per cent) of the sample can plausibly exceed the L
w/L
bol ∼ 0.5 per cent threshold thought necessary for feedback, while 45 per cent may also exceed the less conservative ∼5 per cent of L
bol threshold as well. This suggests that the winds may be energetically significant for AGN–host-galaxy feedback processes.
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