M. Ginolfi, E. Piconcelli, L. Zappacosta, G. C. Jones, L. Pentericci, R. Maiolino, A. Travascio, N. Menci, S. Carniani, F. Rizzo, F. Arrigoni Battaia, S. Cantalupo, C. De Breuck, L. Graziani, K. Knudsen, P. Laursen, V. Mainieri, R. Schneider, F. Stanley, R. Valiante, A. Verhamme
The phase transition between galaxies and quasars is often identified with the rare population of hyper-luminous, hot dust-obscured galaxies. Galaxy formation models predict these systems to grow via mergers, that can deliver large amounts of gas toward their centers, induce intense bursts of star formation and feed their supermassive black holes. Here we report the detection of 24 galaxies emitting Lyman-alpha emission on projected physical scales of about 400 kpc around the hyper-luminous hot dust-obscured galaxy W0410-0913, at redshift z = 3.631, using Very Large Telescope observations. While this indicates that W0410-0913 evolves in a very dense environment, we do not find clear signs of mergers that could sustain its growth. Data suggest that if mergers occurred, as models expect, these would involve less massive satellites, with only a moderate impact on the internal interstellar medium of W0410-0913, which is sustained by a rotationally-supported fast-rotating molecular disk, as Atacama Large Millimeter Array observations suggest.
A. Luminari, F. Tombesi, E. Piconcelli, F. Nicastro, K. Fukumura, D. Kazanas, F. Fiore, L. Zappacosta
Outflows are observed in a variety of astrophysical sources. Remarkably, ultra-fast ($v\geq 0.1c$), outflows in the UV and X-ray bands are often seen in AGNs. Depending on their energy and mass outflow rate, respectively $\dot{E}_{out}, \dot{M}_{out}$, such outflows may play a key role in regulating the AGN-host galaxy co-evolution process through cosmic time. It is therefore crucial to provide accurate estimates of the wind properties. Here, we concentrate on special relativistic effects concerning the interaction of light with matter moving at relativistic speed relatively to the source of radiation. Our aim is to assess the impact of these effects on the observed properties of the outflows and implement a relativistic correction in the existing spectral modelling routines. We define a simple procedure to incorporate relativistic effects in radiative transfer codes. Following this procedure, we run a series of simulations to explore the impact of these effects on the simulated spectra, for different $v$ and column densities of the outflow. The observed optical depth is usually considered a proxy for the wind $N_H$, independently on its velocity. However, our simulations show that the observed optical depth of an outflow with a given column density $N_H$ decreases rapidly as the velocity of the wind approaches relativistic values. This, in turn, implies that when estimating $N_H$ from the optical depth, it is necessary to include a velocity-dependent correction, already for moderate velocities (e.g. $v \geq 0.05c$). This correction linearly propagates to the derived $\dot{M}_{out}, \dot{E}_{out}$. As an example of these effects, we calculate the relativistically corrected values of $\dot{M}_{out}$ and $\dot{E}_{out}$ for a sample of $\sim 30$ Ultra-Fast Outflows taken from the literature, and find correction factors of $20-120 \%$ within the observed range of outflowing velocities.
I. Bartalucci, F. Gastaldello, E. Piconcelli, L. Zappacosta, M. Rossetti, S. Ghizzardi, S. De Grandi, S. Molendi, Marco Laurenti
Nov 26, 2021·astro-ph.CO·PDF We present the characterisation of the massive cluster ClG-J$104803.7+313843$ at $z=0.76$ performed using a serendipitous XMM-Newton observation. High redshift and massive objects represent an ideal laboratory to benchmark our understanding of how cluster form and assembly formation driven mainly by gravity.Leveraging the high throughput of XMM-Newton we were firstly able to determine the redshift of the object, shedding light on ambiguous photometric redshift associations. We investigated the morphology of this cluster which shows signs of merging activities in the outskirts and a flat core. We also measured the radial density profile up to $R_{500}$. With these quantities in hand, we were able to determine the mass, $M_{500}=5.64^{+0.79}_{-0.62} \times 10^{14}M_{\odot}$, using the YX proxy. This quantity improves previous measurement of the mass of this object by a factor of $\sim 3.5$. The characterisation of one cluster at such mass and redshift regime is fundamental as these objects are intrinsically rare, the number of objects discovered so far being less than $\sim 25$. Our study highlights the importance of using X-ray observations in combination with ancillary multi-wavelength data to improve our understanding of high-z and massive clusters
M. Bischetti, C. Feruglio, E. Piconcelli, F. Duras, M. Pèrez-Torres, R. Herrero, G. Venturi, S. Carniani, G. Bruni, I. Gavignaud, V. Testa, A. Bongiorno, M. Brusa, C. Circosta, G. Cresci, V. D'Odorico, R. Maiolino, A. Marconi, M. Mingozzi, C. Pappalardo, M. Perna, E. Traianou, A. Travascio, G. Vietri, L. Zappacosta, F. Fiore
Sources at the brightest end of QSO luminosity function during the peak epoch of star formation and black hole accretion (z~2-4, i.e. Cosmic noon) are privileged sites to study the feeding & feedback cycle of massive galaxies. We perform the first systematic study of cold gas properties in the most luminous QSOs, by characterising their host-galaxies and environment. We analyse ALMA, NOEMA and JVLA observations of FIR continuum, CO and [CII] emission lines in eight QSOs ($L_{\rm Bol}>3\times10^{47}$ erg/s) from the WISSH sample at z~2.4-4.7. We report a 100% emission line detection rate and a 80% detection rate in continuum emission, and we find CO emission to be consistent with the steepest CO ladders observed so far. Sub-mm data reveal presence of (one or more) bright companion galaxies around 80% of WISSH QSOs, at projected distances of 6-130 kpc. We observe a variety of sizes for the molecular gas reservoirs (1.7-10 kpc), associated with rotating disks with disturbed kinematics. WISSH QSOs typically show lower CO luminosity and higher star formation efficiency than FIR matched, z~0-3 main-sequence galaxies, implying that, given the observed SFR ~170-1100 $M_\odot$/yr, molecular gas is converted into stars on <50 Myr. Most targets show extreme dynamical to black-hole mass ratios $M_{\rm dyn}/M_{\rm BH}\sim3-10$, two orders of magnitude smaller than local relations. The molecular gas fraction in WISSH hosts is lower by a factor of ~10-100 than in star forming galaxies with similar $M_*$. WISSH QSOs undergo an intense growth phase of both the central SMBH and host-galaxy. They pinpoint high-density sites where giant galaxies assemble and mergers play a major role in the build-up of the final host-galaxy mass. The observed low molecular gas fraction and short depletion timescale are likely due to AGN feedback, as traced by fast AGN-driven ionised outflows in all our targets.
J. Aird, D. M. Alexander, D. R. Ballantyne, F. Civano, A. Del-Moro, R. C. Hickox, G. B. Lansbury, J. R. Mullaney, F. E. Bauer, W. N. Brandt, A. Comastri, A. C. Fabian, P. Gandhi, F. A. Harrison, B. Luo, D. Stern, E. Treister, L. Zappacosta, M. Ajello, R. Assef, S. E. Boggs, M. Brightman, F. E. Christensen, W. W. Craig, M. Elvis, K. Forster, M. Balokovic, B. W. Grefenstette, C. J. Hailey, M. Koss, S. M. LaMassa, K. K. Madsen, S. Puccetti, C. Saez, C. M. Urry, D. R. Wik, W. Zhang
Nov 13, 2015·astro-ph.HE·PDF We present the first direct measurements of the rest-frame 10-40 keV X-ray luminosity function (XLF) of Active Galactic Nuclei (AGNs) based on a sample of 94 sources at 0.1 < z <3, selected at 8-24 keV energies from sources in the NuSTAR extragalactic survey program. Our results are consistent with the strong evolution of the AGN population seen in prior, lower-energy studies of the XLF. However, different models of the intrinsic distribution of absorption, which are used to correct for selection biases, give significantly different predictions for the total number of sources in our sample, leading to small, systematic differences in our binned estimates of the XLF. Adopting a model with a lower intrinsic fraction of Compton-thick sources and a larger population of sources with column densities N_H ~ 10^{23-24} /cm2 or a model with stronger Compton reflection component (with a relative normalization of R ~ 2 at all luminosities) can bring extrapolations of the XLF from 2-10 keV into agreement with our NuSTAR sample. Ultimately, X-ray spectral analysis of the NuSTAR sources is required to break this degeneracy between the distribution of absorbing column densities and the strength of the Compton reflection component and thus refine our measurements of the XLF. Furthermore, the models that successfully describe the high-redshift population seen by NuSTAR tend to over-predict previous, high-energy measurements of the local XLF, indicating that there is evolution of the AGN population that is not fully captured by the current models.
C. Feruglio, A. Ferrara, M. Bischetti, D. Downes, R. Neri, C. Ceccarelli, C. Cicone, F. Fiore, S. Gallerani, R. Maiolino, N. Menci, E. Piconcelli, G. Vietri, C. Vignali, L. Zappacosta
Jun 17, 2017·astro-ph.GA·PDF We have performed a high sensitivity observation of the UFO/BAL quasar APM 08279+5255 at z=3.912 with NOEMA at 3.2 mm, aimed at detecting fast moving molecular gas. We report the detection of blueshifted CO(4-3) with maximum velocity (v95\%) of $-1340$ km s$^{-1}$, with respect to the systemic peak emission, and a luminosity of $L' = 9.9\times 10^9 ~μ^{-1}$ K km s$^{-1}$ pc$^{-2}$ (where $μ$ is the lensing magnification factor). We discuss various scenarios for the nature of this emission, and conclude that this is the first detection of fast molecular gas at redshift $>3$. We derive a mass flow rate of molecular gas in the range $\rm \dot M=3-7.4\times 10^3$ M$_\odot$/yr, and momentum boost $\dot P_{OF} / \dot P_{AGN} \sim 2-6$, therefore consistent with a momentum conserving flow. For the largest $\dot P_{OF}$ the scaling is also consistent with a energy conserving flow with an efficiency of $\sim$10-20\%. The present data can hardly discriminate between the two expansion modes. The mass loading factor of the molecular outflow $η=\dot M_{OF}/SFR$ is $>>1$. We also detect a molecular emission line at a frequency of 94.83 GHz, corresponding to a rest frame frequency of 465.8 GHz, which we tentatively identified with the cation molecule $\rm N_2H^+$(5-4), which would be the first detection of this species at high redshift. We discuss the alternative possibility that this emission is due to a CO emission line from the, so far undetected, lens galaxy. Further observations of additional transitions of the same species with NOEMA can discriminate between the two scenarios.
F. Fiore, C. Feruglio, F. Shankar, M. Bischetti, A. Bongiorno, M. Brusa, S. Carniani, C. Cicone, F. Duras, A. Lamastra, V. Mainieri, A. Marconi, N. Menci, R. Maiolino, E. Piconcelli, G. Vietri, L. Zappacosta
Feb 15, 2017·astro-ph.GA·PDF Feedback from accreting SMBHs is often identified as the main mechanism responsible for regulating star-formation in AGN host galaxies. However, the relationships between AGN activity, radiation, winds, and star-formation are complex and still far from being understood. We study scaling relations between AGN properties, host galaxy properties and AGN winds. We then evaluate the wind mean impact on the global star-formation history, taking into account the short AGN duty cycle with respect to that of star-formation. We first collect AGN wind observations for 94 AGN with detected massive winds at sub-pc to kpc spatial scales. We then fold AGN wind scaling relations with AGN luminosity functions, to evaluate the average AGN wind mass-loading factor as a function of cosmic time. We find strong correlations between the AGN molecular and ionised wind mass outflow rates and the AGN bolometric luminosity. The power law scaling is steeper for ionised winds (slope 1.29+/-0.38) than for molecular winds (0.76+/-0.06), meaning that the two rates converge at high bolometric luminosities. The molecular gas depletion timescale and the molecular gas fraction of galaxies hosting powerful AGN winds are 3-10 times shorter and smaller than those of main-sequence galaxies with similar SFR, stellar mass and redshift. These findings suggest that, at high AGN bolometric luminosity, the reduced molecular gas fraction may be due to the destruction of molecules by the wind, leading to a larger fraction of gas in the atomic ionised phase. The AGN wind mass-loading factor $η=\dot M_{OF}/SFR$ is systematically higher than that of starburst driven winds. Our analysis shows that AGN winds are, on average, powerful enough to clean galaxies from their molecular gas only in massive systems at z<=2, i.e. a strong form of co-evolution between SMBHs and galaxies appears to break down for the least massive galaxies.
L. Zappacosta, R. Maiolino, F. Mannucci, R. Gilli, P. Schuecker
Feb 24, 2004·astro-ph·PDF We have analyzed the soft X-ray emission in a wide area of the Sculptor supercluster by using overlapping ROSAT PSPC pointings. After subtraction of the point sources we have found evidence for extended, diffuse soft X-ray emission. We have investigated the nature of such extended emission through the cross-correlation with the density of galaxies as inferred from the Muenster Redshift Survey. In particular we have analyzed the correlation as a function of the temperature of the X-ray emitting gas. We have found a significant correlation of the galaxy distribution only with the softest X-ray emission (0.1--0.3 keV) and only for gas temperatures kT < 0.5 keV. We have excluded that this soft X-ray diffuse emission, and its correlation with the galaxy distribution, is significantly contributed by unresolved AGN, group of galaxies or individual galaxies. The most likely explanation is that the soft, diffuse X-ray emission is tracing Warm-Hot Intergalactic Medium, with temperatures below 0.5 keV, associated with the large-scale structures in the Sculptor supercluster.
L. Zappacosta, R. Maiolino, F. Mannucci, R. Gilli, A. Finoguenov, A. Ferrara
Jan 12, 2004·astro-ph·PDF Several popular cosmological models predict that most of the baryonic mass in the local universe is located in filamentary and sheet-like structures associated with groups and clusters of galaxies. This gas is expected to be gravitationally heated to ~10^6 K and therefore emitting in the soft X-rays. We have investigated three fields with large scale structures of galaxies at redshifts 0.1, 0.45, 0.79 and found signatures of warm-hot thermal emission (kT< 1 keV) correlated with the distribution of galaxies for the first two. The correlation and the properties of both X-ray and galaxy distribution strongly suggest that the diffuse X-ray flux is due to extragalactic emission by the Warm-Hot Intergalactic Medium (WHIM) predicted by cosmological models.
G. Lanzuisi, G. Matzeu, P. Baldini, E. Bertola, A. Comastri, F. Tombesi, A. Luminari, V. Braito, J. Reeves, G. Chartas, S. Bianchi, M. Brusa, G. Cresci, E. Nardini, E. Piconcelli, L. Zappacosta, R. Serafinelli, M. Gaspari, R. Gilli, M. Cappi, M. Dadina, M. Perna, C. Vignali, S. Veilleux
Jun 17, 2024·astro-ph.HE·PDF IRASF11119 is an ultra-luminous IR galaxy with post-merger morphology, hosting a type-1 QSO at z=0.189. Its 2013 Suzaku spectrum shows a prominent Ultra Fast Outflow (UFO) absorption feature (v_out~0.25c). In 2021, we obtained the first XMM-Newton long look of the target, coordinated with a simultaneous NuSTAR observation. The new high-quality data allow us to detect at P>99.8% c.l. multiple absorption features associated with the known UFO. 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. We associate the hard band features with blends of FeXXV and FeXXVI He$α$-Ly$α$ and He$β$-Ly$β$ line pairs and infer a large column (N$_H$~$10^{24}$ cm$^{-2}$) of highly ionized (log$ξ$~5) gas outflowing at v_out=0.27c. The 1 keV feature can be associated with a blend of Fe and Ne transitions, produced by a lower column (N$_H$~$10^{21}$ 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 large mass outflow rate, comparable with the mass accretion rate (M$_{out}$=4.25 M$_{Sun}$/yr, ~1.6 M$_{acc}$), and kinetic energy and momentum flux among the highest reported in the literature. We measure an extremely low high-energy cut-off (E$_c$~25 keV). Several other cases in the literature suggest that a steep X-ray continuum may be related to the formation of powerful winds. 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 sources with powerful UFOs, can be explained by (i) a momentum-driven expansion, (ii) an inefficient coupling of the UFO with the host ISM, or (iii) by repeated energy-driven expansion episodes with low duty-cycle, that average out on long time-scales.
L. Zappacosta, E. Piconcelli, F. Fiore, I. Saccheo, R. Valiante, C. Vignali, F. Vito, M. Volonteri, M. Bischetti, A. Comastri, C. Done, M. Elvis, E. Giallongo, F. La Franca, G. Lanzuisi, M. Laurenti, G. Miniutti, A. Bongiorno, M. Brusa, F. Civano, S. Carniani, V. D'Odorico, C. Feruglio, S. Gallerani, R. Gilli, A. Grazian, M. Guainazzi, A. Marinucci, N. Menci, R. Middei, F. Nicastro, S. Puccetti, F. Tombesi, A. Tortosa, V. Testa, G. Vietri, S. Cristiani, F. Haardt, R. Maiolino, R. Schneider, R. Tripodi, L. Vallini, E. Vanzella
The existence of luminous quasars (QSO) at the Epoch of Reionization (EoR; i.e. z>6) powered by supermassive black holes (SMBH) with masses $\gtrsim10^9~M_\odot$ challenges models of early SMBH formation. To shed light on the nature of these sources we started a multiwavelength programme based on a sample of 18 HYPerluminous quasars at the Epoch of ReionizatION (HYPERION). These are the luminous QSOs whose SMBH must have had the fastest mass growth during the Universe first Gyr. In this paper we present the HYPERION sample and report on the first of the 3 years planned observations of the 2.4 Ms XMM-Newton Multi-Year Heritage program on which HYPERION is based. The goal of this program is to accurately characterize the X-ray nuclear properties of QSOs at the EoR. Through a joint X-ray spectral analysis of 10 sources, in the rest-frame $\sim2-50$ keV range, we report a steep average photon index ($Γ\sim2.4\pm0.1$). Absorption is not required. The average $Γ$ is inconsistent at $\geq4σ$ level with the canonical 1.8-2 value measured in QSO at z<6. This spectral slope is also much steeper than that reported in lower-z QSOs with similar luminosity or accretion rate, thus suggesting a genuine redshift evolution. Alternatively, we can interpret this result as the presence of an unusually low-energy cutoff $E_{cut}\sim20$ keV on a standard $Γ=1.9$ power-law. We also report on mild indications that HYPERION QSOs show higher soft X-ray emission at 2 keV compared to the UV one at 2500A than expected by lower-z luminous AGN. We speculate that a redshift-dependent coupling between the corona and accretion disc or intrinsically different coronal properties may account for the steep spectral slopes, especially in the presence of powerful winds. The reported slopes, if confirmed at lower luminosities, may have an important impact on future X-ray AGN studies in the early Universe.
S. Peluso, G. Lanzuisi, A. Comastri, M. Brusa, M. Giustini, G. Miniutti, S. Bianchi, V. E. Gianolli, R. Middei, P-O. Petrucci, L. Borrelli, E. Amenta, E. Bertola, B. De Marco, A. De Rosa, S. Kraemer, G. Kriss, Y. Krongold, S. Mathur, A. Merloni, E. Nardini, F. Panessa, E. Piconcelli, G. Ponti, F. Ricci, A. Tortosa, L. Zappacosta, R. Serafinelli
Mar 18, 2026·astro-ph.HE·PDF We present the X-ray analysis of coronal properties in a statistically representative sample of 23 mostly radio-quiet AGN from the SUBWAYS campaign (SUpermassive Black holes Winds in XrAYs), focusing on quasars at redshifts $0.1 < z < 0.4 $ and bolometric luminosities $2 \times 10^{44} <L_{bol}(erg/s) < 2 \times 10^{46}$. The main aim of this work is to investigate the properties of the hot corona through the study of the hard X-ray band emission, including a proper treatment of the soft X-ray band. High-quality X-ray spectra from XMM-Newton, complemented by NuSTAR data extending up to 30-40 keV in the rest frame, are available for this sample. The soft X-ray band (0.3-2 keV) spectrum is best fitted by a warm corona model with a median temperature of 0.40 keV, and an optical depth in the range $τ$=20 - 40, consistent with previous results on lower luminosity sources. The hard X-ray band is well described using a hot corona model, with a median high-energy cut-off of 87 keV, at the lower end of the distribution of typical values found in Seyfert galaxies (100 - 200 keV). The derived median value of the optical depth ($τ$ = 1 - 5) suggests the presence of a moderately optically thick corona. Combining the SUBWAYS results with literature samples at low and high redshift, we assemble the largest sample to date of AGN with E$_{cut}$ and accretion parameter measurements, finding a significant anticorrelation of E$_{cut}$ with both $λ_{Edd}$ and $L_{bol}$ with the median E$_{cut}$ decreasing from 250 - 300 keV at low accretion rates and luminosities to 90 - 100 keV at high accretion rates and luminosities - consistent with enhanced coronal cooling, possibly driven by pair-production. These results favor cooler, optically thicker coronae in luminous AGN compared to those in lower-luminosity Seyfert galaxies.
E. Amenta, M. Brienza, G. Bruni, M. Brusa, R. Morganti, F. Panessa, R. D. Baldi, E. Behar, G. Lanzuisi, T. Shimwell, F. Tombesi, S. Bianchi, G. Chartas, A. Comastri, G. Cresci, B. De Marco, F. Fiore, M. Gaspari, V. E. Gianolli, R. Gilli, S. B. Kraemer, G. Kriss, Y. Krongold, F. La Franca, A. L. Longinotti, M. Mehdipour, E. Nardini, M. Perna, P. Petrucci, E. Piconcelli, G. Ponti, F. Ricci, L. Zappacosta
Apr 23, 2026·astro-ph.GA·PDF Most Active Galactic Nuclei (AGN) are Radio Quiet, with radio emission that may arise from star-formation activity, AGN-driven winds, weak jets, and coronal activity. Disentangling these mechanisms is challenging and requires detailed multi-wavelength investigation, but it is crucial for quantifying AGN feedback in galaxy evolution. We present a detailed radio investigation of 21 X-ray selected AGN in the Supermassive Black Hole Winds in X-Rays (SUBWAYS) sample (log Lbol = 44.9-46.3 erg/s, z=0.1-0.5), selected to systematically search for Ultra-Fast Outflows (UFOs). UFOs are detected in 30% of the targets, making the sample particularly well-suited for investigating the role and signatures of multi-scale outflows at different frequencies. We build the radio SED of the sources complementing our proprietary data, collected with the JVLA at 1.5 and 6 GHz, with images from LoTSS and other publicly available radio surveys between 150 and 1400 MHz. We investigate the role and occurrence of the aforementioned mechanisms, with particular interest in outflows and their possible relation with UFOs. We combined information on spectral indices, luminosities, and morphologies of the radio emission with properties derived in other wavebands, such as Star Formation Rate, X-ray luminosity, Eddington ratio or the UFO kinetic luminosity. All the sources are detected and are mostly consistent with RQ AGN. For 80% of the sources the data suggest the presence of an outflow (wind or weak jet). Interestingly, our results indicate that AGN with UFOs tend to have larger radio extension and a steep radio spectrum consistent with outflows. Moreover, the radio emission of the 6 UFO hosts is consistent with predictions from wind-driven shock models, possibly indicating a direct connection between the two phases. Alternatively, this may reflect physical conditions favouring the rise of both phenomena.
A. Annuar, D. M. Alexander, P. Gandhi, G. B. Lansbury, D. Asmus, M. Balokovic, D. R. Ballantyne, F. E. Bauer, P. G. Boorman, W. N. Brandt, M. Brightman, C. -T. J. Chen, A. Del Moro, D. Farrah, F. A. Harrison, M. J. Koss, L. Lanz, S. Marchesi, A. Masini, E. Nardini, C. Ricci, D. Stern, L. Zappacosta
Jun 24, 2020·astro-ph.HE·PDF We present $NuSTAR$ observations of four active galactic nuclei (AGN) located within 15 Mpc. These AGN, namely ESO 121-G6, NGC 660, NGC 3486 and NGC 5195, have observed X-ray luminosities of $L_{\rm 2-10\ keV, obs} \lesssim$ 10$^{39}$ erg s$^{-1}$, classifying them as low luminosity AGN (LLAGN). We perform broadband X-ray spectral analysis for the AGN by combining our $NuSTAR$ data with $Chandra$ or $XMM-Newton$ observations to directly measure their column densities ($N_{\rm H}$) and infer their intrinsic power. We complement our X-ray data with archival and new high angular resolution mid-infrared (mid-IR) data for all objects, except NGC 5195. Based on our X-ray spectral analysis, we found that both ESO 121-G6 and NGC 660 are heavily obscured ($N_{\rm H}$ > 10$^{23}$ cm$^{-2}$; $L_{\rm 2-10\ keV,\ int} \sim$ 10$^{41}$ erg s$^{-1}$), and NGC 660 may be Compton-thick. We also note that the X-ray flux and spectral slope for ESO 121-G6 have significantly changed over the last decade, indicating significant changes in the obscuration and potentially accretion rate. On the other hand, NGC 3486 and NGC 5195 appear to be unobscured and just mildly obscured, respectively, with $L_{\rm 2-10\ keV,\ int} <$ 10$^{39}$ erg s$^{-1}$; i.e., genuine LLAGN. Both of the heavily obscured AGN have $L_{\rm bol} >$ 10$^{41}$ erg s$^{-1}$ and $λ_{\rm Edd} \gtrsim$ 10$^{-3}$, and are detected in high angular resolution mid-IR imaging, indicating the presence of obscuring dust on nuclear scale. NGC 3486 however, is undetected in high-resolution mid-IR imaging, and the current data do not provide stringent constraints on the presence or absence of obscuring nuclear dust in the AGN.
A. Luminari, E. Piconcelli, F. Tombesi, L. Zappacosta, F. Fiore, L. Piro, F. Vagnetti
Sep 17, 2018·astro-ph.HE·PDF Outflows from active galactic nuclei (AGN) are often invoked to explain the co-evolution of AGN and their host galaxies, and the scaling relations between the central black hole mass and the bulge velocity dispersion. Nuclear winds are often seen in the X-ray spectra through Fe K shell transitions and some of them are called ultra fast outflows (UFOs) due to their high velocities, up to some fractions of the speed of light. If they were able to transfer some percentage of the AGN luminosity to the host galaxy, this might be enough to trigger an efficient feedback mechanism. We aim to establish new constraints on the covering fraction and on the kinematic properties of the UFO in the powerful (L(bol) ~ 10^(47) erg/s) quasar PDS 456, an established Rosetta stone for studying AGN feedback from disk winds. This will allow us to estimate the mass outflow rate and the energy transfer rate of the wind, which are key quantities to understand the potential impact on the host galaxy. We analyze two sets of simultaneous XMM-Newton and NuSTAR observations taken in September 2013 and reported in Nardini et al. (2015) as having similar broadband spectral properties. We fit the Fe K features with a P-Cygni profile between 5 and 14 keV, using a novel Monte Carlo model for the WINd Emission (WINE). We find an outflow velocity ranging from 0.17 to 0.28 c, with a mean value of 0.23 c. We obtain an opening angle of the wind of 71(+13,-8) deg and a covering fraction of 0.7(+0.2,-0.3), suggesting a wide-angle outflow. We check the reliability of the WINE model by performing extensive simulations of joint XMM-Newton and NuSTAR observations. Furthermore, we test the accuracy of the WINE model in recovering the geometrical properties of UFOs by simulating observations with the forthcoming X-ray observatory ATHENA.
M. Lepore, A. Bongiorno, P. Tozzi, A. Travascio, L. Zappacosta, E. Merlin, R. Fassbender
XDCP0044.0-2033 is the most massive galaxy cluster known at z>1.5 and its core shows a high density of galaxies which are experiencing mergers and hosting nuclear activity. We present a multi-wavelength study of a region located 157 kpc from the center of this galaxy cluster, for which we have photometric and spectroscopic multi-wavelength observations (high resolution HST images in F105W, F140W and F160W bands, NIR KMOS data in H and YJ bands and Chandra ACIS-S X-ray data). Our main goal is to investigate the environmental effects acting on the galaxies inhabiting this high density region. We find that the analyzed region hosts at least nine different sources, six of them confirmed to be cluster members within a narrow redshift range 1.5728<z<1.5762. These sources form two different complexes at a projected distance of $\sim$13 kpc, which are undergoing merging on an estimated timescale off 10-30 Myr. One of the sources shows the presence of a broad H alpha emission line and is classified as Type 1 AGN. This AGN is associated to an X-ray point-like source, whose emission appears moderately obscured (with intrinsic absorption $N_{H} \sim 10^{22} cm^{-2}$) and hosts a relatively massive black hole with mass $M_{BH} \sim 10^{7} M_{\odot}$, which is accreting with an Eddington ratio of $\sim$0.2. We conclude that the analyzed region is consistent with being the formation site of a secondary BCG. These findings, together with an in-depth analysis the X-ray morphology of the cluster, suggest a merging scenario of the entire cluster, with two massive halos both harbouring two rapidly evolving BCGs on the verge of being assembled. Our results are also consistent with the scenario in which the AGN phase in member galaxies is triggered by gas-rich mergers, playing a relevant role in the formation of the red sequence of elliptical galaxies observed in the center of local galaxy clusters.
D. Kakkad, V. Mainieri, G. Vietri, I. Lamperti, S. Carniani, G. Cresci, C. M. Harrison, A. Marconi, M. Bischetti, C. Cicone, C. Circosta, B. Husemann, A. Man, F. Mannucci, H. Netzer, P. Padovani, M. Perna, A. Puglisi, J. Scholtz, G. Tozzi, C. Vignali, L. Zappacosta
We present spatially resolved H$α$ properties of 21 type 1 AGN host galaxies at z$\sim$2 derived from the SUPER survey. These targets were observed with the adaptive optics capabilities of the SINFONI spectrograph, a near-infrared integral field spectrograph, that provided a median spatial resolution of 0.3 arcsec ($\sim$2 kpc). We model the H$α$ emission line profile in each pixel to investigate whether it traces gas in the narrow line region or if it is associated with star formation. To do this, we first investigate the presence of resolved H$α$ emission by removing the contribution of the AGN PSF. We find extended H$α$ emission in sixteen out of the 21 type 1 AGN host galaxies (76%). Based on the BPT diagnostics, optical line flux ratios and the line widths (FWHM), we show that the H$α$ emission in five galaxies is ionised by the AGN (30%), in four galaxies by star formation (25%) and for the rest (45%), the ionisation source is unconstrained. Two galaxies show extended H$α$ FWHM $>$600 km/s, which is interpreted as a part of an AGN-driven outflow. Morphological and kinematic maps of H$α$ emission in targets with sufficient signal-to-noise ratio suggest the presence of rotationally supported disks in six galaxies and possible presence of companions in four galaxies. In two galaxies, we find an anti-correlation between the locations of extended H$α$ emission and [OIII]-based ionised outflows, indicating possible negative feedback at play. However, in the majority of galaxies, we do not find evidence of outflows impacting H$α$ based star formation.
L. Zappacosta, F. Nicastro, R. Maiolino, G. Tagliaferri, D. A. Buote, T. Fang, P. J. Humphrey, F. Gastaldello
Apr 29, 2010·astro-ph.CO·PDF We make use of a 500ks Chandra HRC-S/LETG spectrum of the blazar H2356-309, combined with a lower S/N spectrum of the same target, to search for the presence of warm-hot absorbing gas associated with two Large-Scale Structures (LSSs) crossed by this sightline at z=0.062 (the Pisces-Cetus Supercluster, PCS) and at z=0.128 ("Farther Sculptor Wall", FSW). No statistically significant (>=3sigma) individual absorption is detected from any of the strong He- or H-like transitions of C, O and Ne at the redshifts of the structures. However we are still able to constrain the physical and geometrical parameters of the associated putative absorbing gas, by performing joint spectral fit of marginal detections and upper limits of the strongest expected lines with our self-consistent hybrid ionization WHIM spectral model. At the redshift of the PCS we identify a warm phase with logT=5.35_-0.13^+0.07 K and log N_H =19.1+/-0.2 cm^-2 possibly coexisting with a hotter and less significant phase with logT=6.9^+0.1_-0.8 K and log N_H=20.1^+0.3_-1.7 cm^-2 (1sigma errors). For the FSW we estimate logT=6.6_-0.2^+0.1 K and log N_H=19.8_-0.8^+0.4 cm^-2. Our constraints allow us to estimate the cumulative number density per unit redshifts of OVII WHIM absorbers. We also estimate the cosmological mass density obtaining Omega_b(WHIM)=(0.021^+0.031_-0.018) (Z/Z_sun)^-1, consistent with the mass density of the intergalactic 'missing baryons' for high metallicities.
A. Del Moro, D. M. Alexander, J. A. Aird, F. E. Bauer, F. Civano, J. R. Mullaney, D. R. Ballantyne, W. N. Brandt, A. Comastri, P. Gandhi, F. A. Harrison, G. B. Lansbury, L. Lanz, B. Luo, S. Marchesi, S. Puccetti, C. Ricci, C. Saez, D. Stern, E. Treister, L. Zappacosta
We present a study of the average X-ray spectral properties of the sources detected by the NuSTAR extragalactic survey, comprising observations of the E-CDFS, EGS and COSMOS fields. The sample includes 182 NuSTAR sources (64 detected at 8-24 keV), with 3-24 keV fluxes ranging between $f_{\rm 3-24 keV}\approx10^{-14}$ and $6\times10^{-13}$ erg/cm$^2$/s ($f_{\rm 8-24 keV}\approx3\times10^{-14}-3\times10^{-13}$ erg/cm$^2$/s) and redshifts of $z=0.04-3.21$. We produce composite spectra from the Chandra+NuSTAR data ($E\approx2-40$ keV, rest frame) for all the sources with redshift identifications (95%) and investigate the intrinsic, average spectra of the sources, divided into broad-line (BL) and narrow-line (NL) AGN, and also in different bins of X-ray column density and luminosity. The average power-law photon index for the whole sample is $Γ=1.65_{-0.03}^{+0.03}$, flatter than $Γ\approx1.8$ typically found for AGN. While the spectral slope of BL and X-ray unabsorbed AGN is consistent with typical values ($Γ=1.79_{-0.01}^{+0.01}$), a significant flattening is seen in NL AGN and heavily-absorbed sources ($Γ=1.60_{-0.05}^{+0.08}$ and $Γ=1.38_{-0.12}^{+0.12}$, respectively), likely due to the effect of absorption and to the contribution from Compton reflection to the high-energy flux (E>10 keV). We find that the typical reflection fraction in our spectra is $R\approx0.5$ (for $Γ=1.8$), with a tentative indication of an increase of the reflection strength with column density. While there is no significant evidence for a dependence of the photon index with X-ray luminosity in our sample, we find that $R$ decreases with luminosity, with relatively high levels of reflection ($R\approx1.2$) for $L_{\rm 10-40 keV}<10^{44}$ erg/s and $R\approx0.3$ for $L_{\rm 10-40 keV}>10^{44}$ erg/s AGN, assuming $Γ=1.8$.
A. Travascio, E. Piconcelli, M. Bischetti, G. Cresci, C. Feruglio, M. Perna, G. Vietri, S. Carniani, S. Cantalupo, C. Cicone, M. Ginolfi, G. Venturi, K. Zubovas, A. Bongiorno, M. Brusa, A. Luminari, V. Mainieri, A. Marconi, N. Menci, E. Nardini, A. Pensabene, C. Ramos Almeida, F. Tombesi, C. Vignali, L. Zappacosta, F. Fiore
Mar 26, 2024·astro-ph.GA·PDF PDS 456 is the most luminous RQQ at z<0.3 and can be regarded as a local counterpart of the powerful QSOs shining at Cosmic Noon. It hosts a strong nuclear X-ray ultra-fast outflow, and a massive and clumpy CO(3-2) molecular outflow extending up to 5 kpc from the nucleus. We analyzed the first MUSE WFM and AO-NFM optical integral field spectroscopic observations of PDS456. The AO-NFM observations provide an unprecedented spatial resolution, reaching up to 280 pc. Our findings reveal a complex circumgalactic medium around PDS 456, extending up to a maximum projected size of ~46 kpc. This includes a reservoir of gas with a mass of ~1e7-1e8 Modot, along with eight companion galaxies, and a multi-phase outflow. WFM and NFM MUSE data reveal an outflow on a large scale (~12 kpc from the quasar) in [OIII], and on smaller scales (within 3 kpc) with higher resolution (about 280 pc) in Halpha, respectively. The [OIII] outflow mass rate is 2.3 +/- 0.2 Modot/yr which is significantly lower than those typically found in other luminous quasars. Remarkably, the Ha outflow shows a similar scale, morphology, and kinematics to the CO(3-2) molecular outflow, with the latter dominating in terms of kinetic energy and mass outflow rate by two and one orders of magnitude, respectively. Our results therefore indicate that mergers, powerful AGN activity, and feedback through AGN-driven winds will collectively contribute to shaping the host galaxy evolution of PDS 456, and likely, that of similar objects at the brightest end of the AGN luminosity function across all redshifts. Moreover, the finding that the momentum boost of the total outflow deviates from the expected energy-conserving expansion for large-scale outflows highlights the need of novel AGN-driven outflow models to comprehensively interpret these phenomena.