Massimo Cappi

We present the first results from the WISSHFUL program, an XMM-Newton heritage program targeting luminous quasi-stellar objects (QSOs) at cosmic noon. We report on recent simultaneous XMM-Newton and NuSTAR observations of the super-Eddington accreting quasar WISSH13 at z=3.294, which provide the highest-quality broadband X-ray spectrum to date for a non-lensed QSO at this redshift. Physical modeling of the continuum reveals a soft photon index (Γ ∼ 2) and strong reflection ( R ~ 1.4-1.8), despite the weak narrow Fe emission, and a low high-energy cutoff ( E _cut ∼ 60-80 keV, kT _e = 15-20 keV, depending on the model adopted). Most notably, we detect two significant absorption features (at confidence levels of 96.7% and 98.9%, respectively) at ∼7.5 and ∼10 keV in the rest-frame, interpreted as a blueshifted blend of Fe XXV He α and Fe XXVI Ly α . These features indicate the presence of two kinematic components of a highly ionized, high-column ultrafast outflow (UFO) with a velocity of v _out ∼ 0.1 c and v _out ∼ 0.3 c , respectively. The slower wind is consistently detected in an archival 2017 XMM-Newton observation, whereas the faster wind is detected only in 2024. This stratified and variable wind exhibits extreme energetics, with a mass outflow rate of M _out ∼ 20 M _⊙ /yr (corresponding to 15% M _acc ) for each component, and a kinetic power on the order of ∼1 and ∼10% of the bolometric luminosity, respectively. While this represents one of the most powerful UFOs ever detected, its kinetic power is a similar fraction of the QSO’s bolometric luminosity compared to lower-redshift active galactic nuclei. We present several theoretical frameworks to explain the peculiar accretion and ejection properties of this remarkable QSO at cosmic noon.

Context. Ultra-fast outflows (UFOs) are highly ionized, mildly relativistic winds seen in the X-ray spectra of active galactic nuclei (AGNs) and are thought to influence AGN feedback and galaxy evolution. Aims. In this work, we aim to investigate the UFO signatures by analyzing a large and diverse sample of detections from the literature. Methods. We compiled a sample of 122 solid (> 2 σ c.l.) UFO detections for a total of 57 AGNs, spanning broad ranges in redshift ( z ≲ 4), bolometric luminosity (10 ⁴³ ≲ L _bol ≲ 10 ⁴⁹ erg s ⁻¹ ), black hole mass (10 ⁶ ≲ M _BH / M _⊙ ≲ 10 ¹⁰ ), and Eddington ratio (−2.7 ≲ log λ _Edd ≲ 0.6). We combined results from both phenomenological and photoionization modeling of the absorption features to characterize correlations among UFO parameters. Results. We find evidence for a positive correlation between the line width σ , the equivalent width EW, and the outflow velocity υ _out , with the υ _out − σ trend being comparatively weak. This suggests that the broadest absorption lines with the largest EW are signatures of the fastest UFOs. We further demonstrate that the inferred velocity dispersion, often much larger than the uncertainty on the centroid velocity, should be accounted for in studies of wind energetics and scaling relations. We estimate lower limits on the launching radii of UFOs finding a minimum distance consistent with the innermost stable circular orbit (ISCO) of a weakly or non-rotating Schwarzschild black hole. This apparent truncation at smaller radii may reflect physical constraints, such as the presence of the X-ray corona or observational limitations due to line broadening. Additionally, variations in the line width to velocity ratio imply differences in wind geometry and kinematics. For the first time, we also explore the dependence of UFOs on AGN class. Differences in UFO properties between Seyferts and quasars – bridged by narrow-line Seyfert 1 galaxies – are likely driven by intrinsic parameters such as black hole mass and luminosity. Conclusions. The observed co-variation of υ _out with both σ and EW is consistent with clumpy, multi-component winds propagating through a thermally unstable multiphase medium within the chaotic cold accretion (CCA) cycle. These trends are not unique to a single acceleration mechanism: MHD and line-driven winds remain viable. High-resolution spectroscopy from missions like XRISM and NewAthena is necessary to fully resolve the structure, kinematics, and physical origin of UFOs.

Ultra-soft narrow-line Seyfert 1s (US-NLSy 1s) are a poorly observed class of active galactic nuclei characterised by significant flux changes and an extreme soft X-ray excess. This peculiar spectral shape represents a golden opportunity to test whether the standard framework commonly adopted for modelling local AGNs is still valid. We thus present the results of the joint XMM-Newton and HST monitoring campaign of the highly accreting US-NLSy RBS 1332. The optical-to-UV spectrum of RBS 1332 exhibits evidence for both a stratified narrow-line region and an ionised outflow that produces absorption troughs over a wide range of velocities (from ∼–1500 km s⁻¹ to ∼1700 km s⁻¹) in several high-ionisation transitions (Lyα, N V, C IV). From a spectroscopic point of view, the optical/UV/FUV/X-ray emission of this source is due to the superposition of three distinct components that are best modelled in the context of the two-coronae framework in which the radiation of RBS 1332 can be ascribed to a standard outer disc, a warm Comptonisation region, and a soft coronal continuum. The present dataset is not compatible with a pure relativistic reflection scenario. Finally, the adoption of the novel model REXCOR allowed us to determine that the soft X-ray excess in RBS 1332 is dominated by the emission of the optically thick and warm Comptonising medium, and only a marginal contribution is expected from relativistic reflection from a lamppost-like corona.

The energy released by active galactic nuclei (AGN) has the potential to heat or remove the gas of the ISM, thus likely impacting the cold molecular gas reservoir of host galaxies at first, with star formation following as a consequence on longer timescales. Previous works on high-z galaxies, which compared the gas content of those without identified AGN, have yielded conflicting results, possibly due to selection biases and other systematics. To provide a reliable benchmark for galaxy evolution models at cosmic noon (z = 1 − 3), two surveys were conceived: SUPER and KASHz, both targeting unbiased X-ray-selected AGN at z > 1 that span a wide bolometric luminosity range. In this paper we assess the effects of AGN feedback on the molecular gas content of host galaxies in a statistically robust, uniformly selected, coherently analyzed sample of AGN at z = 1 − 2.6, drawn from the KASHz and SUPER surveys. By using targeted and archival ALMA data in combination with dedicated SED modeling, we retrieve CO and far-infrared (FIR) luminosity as well as M_* of SUPER and KASHz host galaxies. We selected non-active galaxies from PHIBBS, ASPECS, and multiple ALMA/NOEMA surveys of submillimeter galaxies in the COSMOS, UDS, and ECDF fields. By matching the samples in redshift, stellar mass, and FIR luminosity, we compared the properties of AGN and non-active galaxies within a Bayesian framework. We find that AGN hosts at given FIR luminosity are on average CO depleted compared to non-active galaxies, thus confirming what was previously found in the SUPER survey. Moreover, the molecular gas fraction distributions of AGN and non-active galaxies are statistically different, with the distribution of AGN being skewed to lower values. Our results indicate that AGN can indeed reduce the total cold molecular gas reservoir of their host galaxies. Lastly, by comparing our results with predictions from three cosmological simulations (TNG, Eagle, and Simba) filtered to match the properties of observed AGN, AGN hosts, and non-active galaxies, we confirm already known discrepancies and highlight new discrepancies between observations and simulations.

Context. IRASF11119+3257 is an ultra-luminous infrared galaxy with a post-merger morphology, hosting a type-1 quasar at z = 0.189. It shows a prominent ultra-fast outflow (UFO) absorption feature (v_out ∼ 0.25c) in its 2013 Suzaku spectrum. This is the first system in which the energy released by the UFO was compared to that of the known galaxy-scale molecular outflow to investigate the mechanism driving active galactic nuclei (AGN) feedback. Aims. In 2021, we obtained the first XMM-Newton long look of the target, coordinated with a simultaneous NuSTAR observation, with the goal of constraining the broad band continuum and the nuclear wind physical properties and energetics with an unprecedented accuracy. Methods. The new high-quality data allowed us to clearly detect at a confidence level P > 99.8% multiple absorption features associated with the known UFO at the 9.1 and 11.0 keV rest frames. Furthermore, an emission plus absorption feature at 1.1 − 1.3 keV reveals the presence of a blueshifted P-Cygni profile in the soft band. Results. We associate the two hard band features with blends of FeXXV and FeXXVI Heα-Lyα and Heβ-Lyβ line pairs and infer a large column (N_H ∼ 10²⁴ cm⁻²) of highly ionized (log ξ ∼ 5) gas outflowing at v_out = 0.27 ± 0.01c. The 1.3 keV absorption line can be associated with a blend of Fe and Ne transitions, produced by a lower column (N_H ∼ 3 × 10²¹ cm⁻²) and ionization (log ξ ∼ 2.6) gas component outflowing at the same speed. Using a radiative-transfer disk wind model to fit the highly ionized UFO, we derive a mass outflow rate comparable with the mass accretion rate and the Eddington limit (Ṁ_out = 4.25_−0.73^+1.11 M_⊙/yr, ∼1.6 Ṁ_acc and ∼1.0 Ṁ_Edd), and kinetic energy (Ė_kin = 1.21_−0.20^+0.32 L_bol and ∼0.7L_Edd) and momentum flux (Ṗ_out = 6.37_−1.09^+1.67 L_bol/c) among the highest reported in the literature. We measured an extremely low high-energy cutoff (E_cut ∼ 25 − 30 keV). This and several other cases in the literature suggest that a steep X-ray continuum may be related to the formation of powerful winds. We also analyzed the ionized [OIII] component of the large-scale outflow through optical spectroscopy and derived a large outflow velocity (v_out ∼ 3000 km/s) and energetics comparable with the large-scale molecular outflows. Finally, we observe a trend of decreasing outflow velocity from forbidden optical emission lines of decreasing ionization levels, interpreted as the outflow decelerating at large distances from the ionizing source. Conclusions. The lack of a significant momentum boost between the nuclear UFO and the different phases of the large-scale outflow, observed in IRASF11119 and in a growing number of similar sources, can be explained by (i) a momentum-driven expansion, (ii) an inefficient coupling of the UFO with the host interstellar medium, or (iii) by repeated energy-driven expansion episodes with a low duty cycle, that average out on long timescales to produce the observed large-scale outflow.

Context. Accretion disk winds launched close to supermassive black holes (SMBHs) are a viable mechanism providing feedback between the SMBH and the host galaxy. Aims. We aim to characterize the X-ray properties of the inner accretion disk wind of the nearby active galactic nucleus PG 1126-041 and to study its connection with the UV-absorbing wind. Methods. We performed a spectroscopic analysis of eight XMM-Newton observations of PG 1126-041 taken between 2004 and 2015, using both phenomenological models and the most advanced accretion disk wind models available. For half of the data set, we were able to compare the X-ray analysis results with the results of quasi-simultaneous, high-resolution, spectroscopic UV observations taken with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. Results. The X-ray spectra of PG 1126-041 are complex and absorbed by ionized material, which is highly variable on multiple timescales, sometimes as short as 11 days. Accretion disk wind models can account for most of the X-ray spectral complexity of PG 1126-041, with the addition of massive clumps, represented by a partially covering absorber. Variations in column density (N_H ∼ 5 − 20 × 10²² cm⁻²) of the partially covering absorber drive the observed X-ray spectral variability of PG 1126-041. The absorption from the X-ray partially covering gas and from the blueshifted C IV troughs appear to vary in a coordinated way. Conclusions. The line of sight toward PG 1126-041 offers a privileged view through a highly dynamic nuclear wind originating on inner accretion disk scales, making the source a very promising candidate for future detailed studies of the physics of accretion disk winds around SMBHs.

We present new jointXMM-NewtonandNuSTARobservations of APM 08279+5255, a gravitationally-lensed, broad-absorption line quasar (z = 3.91). After showing a fairly stable flux (f_2 − 10 ≃ 4 − 5.5 × 10⁻¹³erg s⁻¹) from 2000 to 2008, APM 08279+5255 was found in a fainter state in the latest X-ray exposures (f_2 − 10 ≃ 2.7 × 10⁻¹³erg s⁻¹), which can likely be ascribed to a lower X-ray activity. Moreover, the 2019 data present a prominent Fe Kαemission line and do not show any significant absorption line. This fainter state, coupled to the first hard X-ray sampling of APM 08279+5255, allowed us to measure X-ray reflection and the high-energy cutoff in this source for the first time. From the analysis of previousXMM-NewtonandChandraobservations, X-ray reflection is demonstrated to be a long-lasting feature of this source, but less prominent prior to 2008, possibly due to a stronger primary emission. The estimated high-energy cutoff (E_cut = 99₋₃₅⁺⁹¹keV) sets a new redshift record for the farthest ever measured and places APM 08279+5255 in the allowed region of the compactness-temperature diagram of X-ray coronae, in agreement with previous results on high-zquasars.

We report X-ray observations of the most distant known gravitationally lensed quasar, J0439+1634 at z = 6.52, which is also a broad absorption line (BAL) quasar, using the XMM-Newton Observatory. With a 130 ks exposure, the quasar is significantly detected as a point source at the optical position with a total of 358 − 19 + 19 net counts using the EPIC instrument. By fitting a power law plus Galactic absorption model to the observed spectra, we obtain a spectral slope of Γ = 1.45 − 0.09 + 0.10 . The derived optical-to-X-ray spectral slope α _ox is − 2.07 − 0.01 + 0.01 , suggesting that the X-ray emission of J0439+1634 is weaker by a factor of 18 than the expectation based on its 2500 Å luminosity and the average α _ox versus luminosity relationship. This is the first time that an X-ray weak BAL quasar at z > 6 has been observed spectroscopically. Its X-ray weakness is consistent with the properties of BAL quasars at lower redshift. By fitting a model including an intrinsic absorption component, we obtain intrinsic column densities of N H = 2.8 − 0.6 + 0.7 × 10 23 cm − 2 and N H = 4.3 − 1.5 + 1.8 × 10 23 cm − 2 , assuming a fixed Γ of 1.9 and a free Γ, respectively. The intrinsic rest-frame 2–10 keV luminosity is derived as (9.4–15.1) × 10⁴³ erg s⁻¹, after correcting for lensing magnification (μ = 51.3). The absorbed power-law model fitting indicates that J0439+1634 is the highest redshift obscured quasar with a direct measurement of the absorbing column density. The intrinsic high column density absorption can reduce the X-ray luminosity by a factor of 3–7, which also indicates that this quasar could be a candidate intrinsically X-ray weak quasar.

We present results from a comprehensive study of ultrafast outflows (UFOs) detected in a sample of 14 quasars, 12 of which are gravitationally lensed, in a redshift range of 1.41–3.91, near the peak of the active galactic nucleus (AGN) and star formation activity. New XMM-Newton observations are presented for six of them, which were selected to be lensed and contain a narrow absorption line (NAL) in their UV spectra. Another lensed quasar was added to the sample, albeit already studied because it was not searched for UFOs. The remaining seven quasars of our sample are known to contain UFOs. The main goals of our study are to infer the outflow properties of high-z quasars, constrain their outflow induced feedback, study the relationship between the outflow properties and the properties of the ionizing source, and compare these results to those of nearby AGN. Our study adds six new detections (> 99% confidence) of UFOs at z > 1.4, almost doubling the current number of cases. Based on our survey of six quasars selected to contain a NAL and observed with XMM-Newton, the coexistence of intrinsic UV NALs and UFOs is found to be significant in >83% of these quasars suggesting a link between multiphase AGN feedback properties of the meso- and microscale. The kinematic luminosities of the UFOs of our high-z sample are large compared to their bolometric luminosities (median of L _K/L _Bol ≳ 50%). This suggests they provide efficient feedback to influence the evolution of their host galaxies and that magnetic driving may be a significant contributor to their acceleration.