arXiv subjects

E. Piconcelli

Publications and source records attributed to E. Piconcelli.

At least 55 records · Page 3Linked to original sources

arXiv2023

X-HESS: a large sample of highly accreting serendipitous AGN under the XMM-Newton microscope

The bulk of X-ray spectroscopic studies of active galactic nuclei (AGN) are focused on local ($z < 0.1$) sources with low-to-moderate ($< 0.3$) Eddington ratio ($λ_\mathrm{Edd}$). It is then mandatory to overcome this limitation and improve our understanding of highly accreting AGN. In this work we present the preliminary results from the analysis of a sample of $\sim70$ high-$λ_\mathrm{Edd}$ radio-quiet AGN at $0.06 \leq z \leq 3.3$, based on the 10th release of the XMM-Newton serendipitous source catalogue, that we named as XMM-Newton High-Eddington Serendipitous AGN Sample (X-HESS). Almost $\sim35\%$ of the X-HESS AGN have multi-epoch archival observations and $\sim70\%$ of the sources can rely on simultaneous OM optical data. First results reveal sources showing signatures of ultra-fast outflows and remarkable long- and short-term X-ray flux variations. Indeed in J095847.88+690532.7 ($z \sim 1.3$), one of the most densely monitored objects hosting a $\sim$$10^9\,M_\odot$ supermassive black hole, we discovered a variation of the soft X-ray flux by a factor of > 2 over approximately one week (rest-frame). Large variations in the power-law continuum photon index $Γ$ are also observed, questioning expectations from previously reported $Γ- λ_\mathrm{Edd}$ relations, for which $Γ\geq 2$ would be a ubiquitous hallmark of AGN with $λ_\mathrm{Edd} \sim 1$.

astro-ph.GA↗

arXiv2023

Tracking the spectral properties across the different epochs in ESO 511-G030

The Type I active galactic nucleus (AGN) ESO 511-G030, a formerly bright and soft-excess dominated source, has been observed in 2019 in the context of a multi-wavelength monitoring campaign. However, in these novel exposures, the source was found in a $\sim$10 times lower flux state, without any trace of the soft-excess. Interestingly, the X-ray weakening corresponds to a comparable fading of the UV suggesting a strong link between these components. The UV/X-ray spectral energy distribution (SED) of ESO 511-G030 shows remarkable variability. We tested both phenomenological and physically motivated models on the data finding that the overall emission spectrum of ESO 511-G030 in this extremely low flux state is the superposition of a power-law-like continuum ($Γ\sim$1.7) and two reflection components emerging from hot and cold matter. has Both the primary continuum and relativistic reflection are produced in the inner regions. The prominent variability of ESO 511-G030 and the lack of a soft-excess can be explained by the dramatic change in the observed accretion rate, which dropped from an L/L$_{\rm Edd}$ of 2\% in 2007 to 0.2\% in 2019. The X-ray photon index also became harder during the low flux 2019 observations, perhaps as a result of a photon starved X-ray corona.

astro-ph.HE↗

arXiv2022

Supermassive Black Hole Winds in X-rays -- SUBWAYS. I. Ultra-fast outflows in QSOs beyond the local Universe

We present a new X-ray spectroscopic study of $22$ luminous ($2\times10^{45}\lesssim L_{\rm bol}\rm /erg\,s^{-1} \lesssim 2\times10^{46}$) active galactic nuclei (AGNs) at intermediate-redshift ($0.1 \lesssim z \lesssim 0.4$), as part of the SUpermassive Black hole Winds in the x-rAYS (SUBWAYS) sample, mostly composed of quasars (QSOs) and type\,1 AGN. Here, 17 targets were observed with \textit{XMM-Newton} between 2019--2020 and the remaining 5 are from previous observations. The aim of this large campaign ($1.45\,\rm Ms$ duration) is to characterise the various manifestations of winds in the X-rays driven from supermassive black holes in AGN. In this paper we focus on the search and characterization of ultra-fast outflows (UFOs), which are typically detected through blueshifted absorption troughs in the Fe\,K band ($E>7\,\rm keV$). By following Monte Carlo procedures, we confirm the detection of absorption lines corresponding to highly ionised iron (e.g., Fe\,\textsc{xxv}\,H$α$, Fe\,\textsc{xxvi}\,Ly$α$) in 7/22 sources at the $\gtrsim95\%$ confidence level (for each individual line). The global combined probability of such absorption features in the sample is $>99.9\%$. The SUBWAYS campaign extends at higher luminosity and redshifts than previous local studies on Seyferts, obtained using \xmm and \suzaku observations. We find a UFO detection fraction of $\sim30\%$ on the total sample that is in agreement with the previous findings. This work independently provides further support for the existence of highly-ionised matter propagating at mildly relativistic speed ($\gtrsim0.1c$) in a considerable fraction of AGN over a broad range of luminosities, which is expected to play a key role in the self-regulated AGN feeding-feedback cycle, as also supported by hydrodynamical multiphase simulations.

astro-ph.HE↗

arXiv2022

Supermassive Black Hole Winds in X-rays: SUBWAYS. II. HST UV spectroscopy of winds at intermediate redshifts

We present a UV spectroscopic study of ionized outflows in 21 active galactic nuclei (AGN), observed with the HST. The targets of the SUBWAYS sample were selected with the aim to probe the parameter space of the underexplored AGN between the local Seyfert galaxies and the luminous quasars at high redshifts. Our targets, spanning redshifts of 0.1-0.4 and bolometric luminosities (L_bol) of 10^45-10^46 erg/s, have been observed with a large multi-wavelength campaign. Here, we model the UV spectra and look for different types of AGN outflows. We find that 60% of our targets show a presence of outflowing H I absorption, while 40% exhibit ionized outflows seen as absorption by either C IV, N V, or O VI. This is comparable to the occurrence of ionized outflows seen in the local Seyfert galaxies. All UV absorption lines in the sample are relatively narrow, with outflow velocities reaching up to -3300 km/s. We did not detect any UV counterparts to the X-ray ultra-fast outflows (UFOs), most likely due to their being too highly ionized. However, all SUBWAYS targets with an X-ray UFO demonstrate the presence of UV outflows at lower velocities. We find significant correlations between the column density (N) of the UV ions and L_bol of the AGN, with N of H I decreasing with L_bol, while N of O VI is increasing with L_bol. This is likely to be a photoionization effect, where toward higher AGN luminosities, the wind becomes more ionized, resulting in less absorption by neutral or low-ionization ions and more absorption by high-ionization ions. In addition, we find that N of the UV ions decreases as their outflow velocity increases. This may be explained by a mechanical power that is evacuating the UV-absorbing medium. Our observed relations are consistent with multiphase AGN feeding and feedback simulations indicating that a combination of both radiative and mechanical processes are in play.

astro-ph.HE↗

arXiv2022

Breaking the rules at $z\simeq$0.45: the rebel case of RBS 1055

We report on a long (250 ks) NuSTAR observation of the bright quasar RBS 1055 performed in March 2021, and archival XMM-Newton pointings (185 ks) taken in July 2014. An optical spectrum of the source taken with the Double Spectrograph at the Palomar Observatory, quasi-simultaneous with the NuSTAR observations, is also analyzed. We find that the two-coronae model, in which a warm and hot corona coexist, well reproduces its broad band spectrum, with temperatures kT$_e=0.12^{+0.08}_{-0.03}$ keV, kT$_e=30^{+40}_{-10}$ keV and Thomson optical depths $τ$=30$_{-10}^{+15}$ and $τ$=3.0$_{-1.4}^{+1.0}$ for the former and the latter component, respectively. We confirm the presence of an intense Fe K$α$ emission line (EW=55$\pm$6 eV) and, when a toroidal model is considered for reproducing the Compton reflection, a Compton-thin solution with N$_{\rm H}=(3.2^{+0.9}_{-0.8})\times10^{23}$ cm$^{-2}$ for the circumnuclear reflector is found. The analysis of the optical spectrum reveals a likely peculiar configuration of our line of sight with respect to the nucleus, and the presence of a broad [O III] component, tracing outflows in the NLR, with a velocity shift $v=$1500$\pm100$ km s$^{-1}$, leading to a mass outflow rate $\dot{M}_{\rm out}=25.4\pm1.5$ M$_{\odot}$ yr$^{-1}$ and outflow kinetic power $\dot{E}_{\rm kin}$/L$_{\rm Bol}$ $\sim$0.33%. We estimate the BH mass to be in the range 2.8$\times$10$^{8}$-1.2$\times$10$^{9}$ M$_{\odot}$, according to different BLR emission lines, with an average value of <$M\rm_{BH}$>=6.5$\times$10$^{8}$ M$_{\odot}$. With an Fe K$α$ which is 3$σ$ above the value predicted from the EW-L$_{2-10\ \rm keV}$ relation and an extreme source brightness at 2 keV (a factor 10-15 higher than the one expected from the optical/UV), RBS 1055 confirms to be an outlier in the X-rays, compared to other objects in the same luminosity and redshift range.

astro-ph.HE↗

arXiv2022

Detection of companion galaxies around hot dust-obscured hyper-luminous galaxy W0410-0913

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.

astro-ph.GA↗

arXiv2022

The black hole and host galaxy growth in an isolated $z\sim 6$ QSO observed with ALMA

The outstanding mass growth of supermassive black holes (SMBHs) at the Reionisation Epoch and how it is related to the concurrent growth of their host galaxies, poses challenges to theoretical models aimed at explaining how these systems formed in short timescales (<1 Gyr). To trace the average evolutionary paths of quasi-stellar objects (QSOs) and their host galaxies in the BH mass-host mass ($M_{\rm dyn}$) plane, we compare the star formation rate (SFR), derived from the accurate estimate of the dust temperature and the dust mass ($T_{\rm dust}, M_{\rm dust}$), with the BH accretion rate. To this aim, we analysed a deep, $900$ pc resolution ALMA observation of the sub-mm continuum, [CII] and H$_2$O of the $z\sim 6$ QSO J2310+1855, enabling a detailed study of dust properties and cold gas kinematics. We performed an accurate SED analysis obtaining a dust temperature of $T_{\rm dust} = 71$ K and a dust mass of $M_{\rm dust}= 4.4 \times 10^8\ \rm M_{\odot}$. The implied AGN-corrected SFR is $1240 \ \rm M_{\odot}yr^{-1}$, a factor of 2 smaller than previously reported for this QSO. We derived the best estimate of the dynamical mass $M_{\rm dyn} = 5.2\times 10^{10}\ \rm M_{\odot}$ within $r = 1.7$ kpc, based on a dynamical model of the system. We found that ${\rm SFR}/M_{\rm dyn}>\dot M_{\rm BH}/M_{\rm BH}$, suggesting that AGN feedback might be efficiently acting to slow down the SMBH accretion, while the stellar mass assembly is still vigorously taking place in the host galaxy. In addition, we were also able to detect high-velocity emission on the red and blue sides of the [CII] emission line, that traces a gaseous outflow, and for the first time, we mapped a spatially-resolved water vapour disk through the H$_2$O v=0 $3_{(2,2)}-3_{(1,3)}$ emission line detected at $ν_{\rm obs} = 274.074$ GHz, whose kinematic properties and size are broadly consistent with those of the [CII] disk.

astro-ph.GA↗

arXiv2022

Widespread, strong outflows in XQR-30 quasars at the Reionisation epoch

Luminous quasars powered by accretion onto billion solar mass black holes already exist at the epoch of Reionisation, when the Universe was 0.5-1 Gyr old. These objects likely reside in over-dense regions of the Universe, and will grow to form today's giant galaxies. How their huge black holes formed in such short times is debated, particularly as they lie above the local black hole mass-galaxy dynamical mass correlation, thus following the black hole-dominance growth path. It is unknown what slowed down the black hole growth, leading towards the symbiotic growth observed in the local Universe, and when this process started, although black hole feedback is a likely driver. This deadlock is due to the lack of large, homogeneous samples of high-redshift quasars with high-quality, broad-band spectroscopic information. Here we report results from a VLT/X-shooter survey of 30 quasars at redshift 5.8$\le$z$\le$6.6 (XQR-30). About 50% of their spectra reveal broad blue-shifted absorption line (BAL) throughs, tracing powerful ionised winds. The BAL fraction in z$\gtrsim$6 quasars is 2-3 times higher than in quasars at z~2-4.5. XQR-30 BAL quasars exhibit extreme outflow velocities, up to 17% of the light speed, rarely observed at lower redshift. These outflows inject large amounts of energy into the galaxy interstellar medium, which can contrast nuclear gas accretion, slowing down the black-hole growth. The star-formation rate in high-z quasar hosts is generally $>$100 M$_\odot$/yr, so these galaxies are growing at a fast rate. The BAL phase may then mark the beginning of significant feedback, acting first on black hole growth and possibly later on galaxy growth. The red optical colors of BAL quasars at z$\gtrsim$6 indeed suggest that these systems are dusty and may be caught during an initial quenching phase of obscured accretion.

astro-ph.GA↗

arXiv2022

The intermediate-ionization lines as virial broadening estimators for Population A quasars

The identification of a virial broadening estimator in the quasar UV rest frame suitable for black hole mass computation at high redshift has become an important issue. We compare the HI Balmer H-beta line width to the ones of two intermediate ionization lines: the Aliii 1860 doublet and the Ciii] 1909 line, over a wide interval of redshift and luminosity (0 < z < 3.5; 43 < logL < 48.5 [erg a/]), for 48 sources belonging to the quasar population characterized by mid-to-high values of the Eddington ratio (Population A). The present analysis indicates that the line width of Aliii 1860 and H-beta are highly correlated, and can be considered equivalent for most Population A quasars over five orders of magnitude in luminosity; forCiii] 1909, multiplication by a constant correction factor xi ~ 1.25 is sufficient to bring the FWHM of Ciii] in agreement with the one of H-betaa. The statistical concordance between low-ionization and intermediate-ionization lines suggests that they predominantly arise from the same virialized part of the broad line region. However, blueshifts of modest amplitude (few hundred km /s) with respect to the quasar rest frame and an excess (~ 1.1) Aliii broadening with respect to H-beta are found in a fraction of our sample. Scaling laws to estimate M_BH of high redshift quasar using the Aliii and the Ciii] line widths have rms scatter ~ 0.3 dex. The Aliii scaling law takes the form log M_BH ~ 0.58 log L1700,44 + 2 log FWHM + 0.49 [solar masses].

astro-ph.GA↗

arXiv2022

The WISSH quasars project X. Discovery of a multi-component and highly-variable UV ultra-fast outflow in a z=3.6 quasar

We report on the variability of a multi-component broad absorption line (BAL) system observed in the hyper-luminous quasar J1538+0855 at z=3.6. Observations from SDSS, VLT, LBT and Subaru telescopes taken at five different epochs, spanning 17 yr in the observed frame, are presented. We detect three (A, B, C) CIV variable troughs exhibiting extreme velocities ($\sim$40,000-54,000 km s$^{-1}$) similar to the ultra-fast outflows (UFOs) typically observed in the X-ray spectra. The A component of the BAL UFO ($\rm v_{ufo}$ $\sim$0.17 c) shows strength variations, while B ($\rm v_{ufo}$ $\sim$0.15 c) and C ($\rm v_{ufo}$ $\sim$0.13 c) components show changes both in shape and strength, appearing and disappearing at different epochs. In addition, during the last observation on June 2021 the entire BAL system disappears. The variability trends observed during the first two epochs (1.30 yr rest-frame) in the CIV, SiIV, OVI and NV absorption spectral regions are the same for B and C troughs, while the A component of the BAL varies independently. This suggests a change in the ionization state of the absorbing gas for B and C components and tangential motion for the A component, as causes of this temporal behavior. Accordingly, it is possible to provide an upper limit for distance of the gas responsible for the A component of $R\rm_{out}^{A}$$\le$58 pc, and in turn, a kinetic power of $\dot{E}\rm_{K,ufo}$ $\le$5.2 $\times$ 10$^{44}$ erg s$\rm^{-1}$. We also obtain $R\rm_{out}^{B,C}$ $\le$2.7 kpc for B and C components, which implies an upper limit estimation of $\dot{E}\rm_{K,ufo}$ $\le$2.1$\times$10$^{46}$ erg s$\rm^{-1}$ and $\dot{E}\rm_{K,ufo}$ $\le$1.4$\times$10$^{46}$ erg s$\rm^{-1}$, respectively. Future spectral monitoring with high-resolution instruments is mandatory to accurately constrain physical properties of the BAL UFO discovered in the UV spectrum of J1538+0855.

astro-ph.GA↗

arXiv2022

The properties of the X-ray corona in the distant ($z=3.91$) quasar APM 08279+5255

We present new joint XMM-Newton and NuSTAR observations of APM 08279+5255, a gravitationally-lensed, broad-absorption line quasar ($z=3.91$). After showing a fairly stable flux ($f_{\rm2-10}\simeq4-5.5\times10^{-13}\rm~erg~s^{-1}$) from 2000 to 2008, APM 08279+5255 was found in a fainter state in the latest X-ray exposures ($f_{\rm2-10}\simeq2.7\times10^{-13}\rm~erg~s^{-1}$), which can likely be ascribed to a lower X-ray activity. Moreover, the 2019 data present a prominent Fe K$α$ emission 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 previous XMM-Newton and Chandra observations, 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 ($E_{\rm cut}=99_{-35}^{+91}$ keV) 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-$z$ quasars.

astro-ph.HE↗

arXiv2021

X-ray characterisation of the massive galaxy clusterClG-J104803.7+313843 at z=0.76 with XMM-Newton

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

astro-ph.CO↗

arXiv2021

X-ray spectroscopic survey of highly-accreting AGN

Improving our understanding of the nuclear properties of high-Eddington ratio ($λ_\mathrm{Edd}$) active galactic nuclei (AGN) is necessary since the bulk of X-ray spectroscopic studies have been focused on low-Eddington AGN. We present here the X-ray spectral analysis of 14 radio-quiet, $λ_\mathrm{Edd}\gtrsim1$ AGN at $0.4\leq z \leq 0.75$, observed with XMM-Newton. Optical/UV data from simultaneous Optical Monitor observations have been also considered. These AGN have been selected to have relatively high values of black hole mass ($M_\mathrm{BH}\sim10^{8-8.5}M_\odot$) and bolometric luminosity ($L_\mathrm{bol} \sim 10^{46}$ erg s$^{-1}$), in order to complement previous studies of high-Eddington AGN at lower $M_\mathrm{BH}$ and $L_\mathrm{bol}$. We studied the relation between $λ_\mathrm{Edd}$ and other key X-ray spectral parameters, such as the photon index of the power-law continuum $Γ$, the X-ray bolometric correction $k_\mathrm{bol,X}$ and $α_\mathrm{ox}$. Despite the homogeneous optical and SMBH accretion properties, the X-ray properties of these high-Eddington AGN are quite heterogeneous. We measured values of $Γ$ comprised between 1.3 and 2.5, at odds with the expectations based on previously reported $Γ-λ_\mathrm{Edd}$ relations, by which $Γ\geq2$ would be an ubiquitous hallmark of AGN with $λ_\mathrm{Edd}\sim1$. We found that $\sim30\%$ of the sources are X-ray weak, with an X-ray emission about a factor of $\sim10-80$ fainter than that of typical AGN at similar UV luminosities. The X-ray weakness seems to be intrinsic and not due to intervening obscuration. This may indicate that high-Eddington AGN commonly undergo periods of intrinsic X-ray weakness. Furthermore, results from a follow-up monitoring with Swift of one of these X-ray weak AGN suggest that these periods can last for several years.

astro-ph.GA↗

arXiv2021

SUPER. VI. A giant molecular halo around a z~2 quasar

We present the discovery of copious molecular gas in the halo of cid_346, a $z=2.2$ quasar studied as part of the SINFONI survey for Unveiling the Physics and Effect of Radiative feedback (SUPER). New Atacama Compact Array (ACA) CO(3-2) observations detect a much higher flux (by a factor of $14\pm5$) than measured on kiloparsec scales ($r\lesssim8$ kpc) using previous snapshot Atacama Large Millimeter/submillimeter Array data. Such additional CO(3-2) emission traces a structure that extends out to $r\sim200$ kpc in projected size, as inferred through direct imaging and confirmed by an analysis of the uv visibilities. This is the most extended molecular circumgalactic medium (CGM) reservoir that has ever been mapped. It shows complex kinematics, with an overall broad line profile (FWHM $= 1000$ km/s) that is skewed towards redshifted velocities up to at least $v\sim1000$ km/s. Using the optically thin assumption, we estimate a strict lower limit for the total molecular CGM mass observed by ACA of $M_{mol}^{CGM}>10^{10}~M_{\odot}$. There is however room for up to $M^{CGM}_{mol}\sim 1.7\times 10^{12}$ $M_{\odot}$, once optically thick CO emission with $α_{\rm CO}=3.6$ $\rm M_{\odot}~(K~km~s^{-1}~pc^2)^{-1}$ and $L^{\prime}_{CO(3-2)}/L^{\prime}_{CO(1-0)}=0.5$ are assumed. Since cid_346 hosts quasar-driven ionised outflows and since there is no evidence of merging companions or an overdensity, we suggest that outflows may have played a crucial rule in seeding metal-enriched, dense gas on halo scales. However, the origin of such an extended molecular CGM remains unclear.

astro-ph.GA↗

arXiv2021

The IBISCO survey: I. Multiphase discs and winds in the Seyfert galaxy Markarian 509

We present the analysis of the ALMA CO(2-1) emission line and the underlying 1.2 mm continuum of Mrk509 with spatial resolution of 270 pc. This local Seyfert 1.5 galaxy, optically classified as a spheroid, is known to host a ionised disc, a starburst ring, and ionised gas winds on both nuclear and galactic scales. From CO(2-1) we estimate a molecular gas mass $M_{H_2}=1.7\times 10^9\, \rm M_{\odot}$, located within a disc of size 5.2 kpc, with $M_{dyn}$=(2.0$\pm$1.1) $\times$ $10^{10}\, \rm M_{\odot}$ inclined at $44\pm10$ deg. The molecular gas fraction within the disc is $μ_{gas}=5\%$. The gas kinematics in the nuclear region within r=700 pc suggests the presence of a warped nuclear disc. Both the presence of a molecular disc with ongoing star-formation in a starburst ring, and the signatures of a minor merger, are in agreement with the scenario where galaxy mergers produce gas destabilization, feeding both star-formation and AGN activity. The spatially-resolved Toomre Q-parameter across the molecular disc is in the range $Q_{gas}=0.5-10$, and shows that the disc is marginally unstable across the starburst ring, and stable at nucleus and in a lopsided ring-like structure located inside of the starburst ring. We find complex molecular gas kinematics and significant kinematics perturbations at two locations, one within 300 pc from the nucleus, and one 1.4 kpc away close to the region with high $Q_{gas}$, that we interpret as molecular winds. The total molecular outflow rate is in the range 6.4-17.0 $\rm M_\odot/yr$. The molecular wind total kinetic energy is consistent with a multiphase momentum-conserving wind driven by the AGN with $\dot{P}_{of}/\dot{P}_{rad}$ in the range 0.06-0.5. The spatial overlap of the inner molecular wind with the ionised wind, and their similar velocity suggest a cooling sequence within a multiphase AGN driven wind.

astro-ph.GA↗

arXiv2021

X-ray obscuration from a variable ionized absorber in PG 1114+445

Photoionized absorbers of outflowing gas are commonly found in the X-ray spectra of active galactic nuclei (AGN). While most of these absorbers are seldom significantly variable, some ionized obscurers have been increasingly found to substantially change their column density on a wide range of time scales. These $N_\text{H}$ variations are often considered as the signature of the clumpy nature of the absorbers. Here we present the analysis of a new Neil Gehrels Swift Observatory campaign of the type-1 quasar PG 1114+445, which was observed to investigate the time evolution of the multiphase outflowing absorbers previously detected in its spectra. The analyzed dataset consists of 22 observations, with a total exposure of $\sim90$ ks, spanning about $20$ months. During the whole campaign, we report an unusually low flux state with respect to all previous X-ray observations of this quasar. From the analysis of the stacked spectra we find a fully covering absorber with a column density $\log(N_\text{H}/\text{cm}^{-2})=22.9^{+0.3}_{-0.1}$. This is an order of magnitude higher than the column density measured in the previous observations. This is either due to a variation of the known absorbers, or by a new one, eclipsing the X-ray emitting source. We also find a ionization parameter of $\log(ξ/\text{erg cm s}^{-1})=1.4^{+0.6}_{-0.2}$. Assuming that the obscuration lasts for the whole duration of the campaign, i.e. more than $20$ months, we estimate the minimum distance of the ionized clump, which is located at $r\gtrsim0.5$ pc.

astro-ph.GA↗

arXiv2021

The role of SPICA-like missions and the Origins Space Telescope in the quest for heavily obscured AGN and synergies with Athena

In the BH-galaxy co-evolution framework, most of the star-formation (SF) and the black hole (BH) accretion is expected to take place in highly obscured conditions. Thus, obscured AGN are difficult to identify in optical or X-ray bands, but shine bright in the IR. Moreover, X-ray background (XRB) synthesis models predict that a large fraction of the yet-unresolved XRB is due to the most obscured (Compton thick, CT) of these AGN. In this work, we investigate the synergies between putative IR missions (using SPICA, proposed for ESA/M5 but withdrawn in October 2020, and Origins Space Telescope, OST, as `templates') and the X-ray mission Athena, which should fly in early 2030s, in detecting and characterizing AGN, with a particular focus on the most obscured ones. Using an XRB synthesis model, we estimated the number of AGN and the number of those which will be detected in the X-rays. For each AGN we associated an optical-to-FIR SED from observed AGN with both X-ray data and SED decomposition, and used these SEDs to check if the AGN will be detected by SPICA-like or OST at IR wavelengths. We expect that, with the deepest Athena and SPICA-like (or OST) surveys, we will be able to detect in the IR more than $90\,\%$ of all the AGN (down to L$_{2-10\text{keV}} \sim 10^{42}\,$erg/s and up to $z \sim 10$) predicted by XRB synthesis modeling, and we will detect at least half of them in the X-rays. Athena will be extremely powerful in detecting and discerning moderate- and high-luminosity AGN. We find that the most obscured and elusive CT-AGN will be exquisitely sampled by SPICA-like mission or OST and that Athena will allow a fine characterization of the most-luminous ones. This will provide a significant step forward in the process of placing stronger constraints on the yet-unresolved XRB and investigating the BH accretion rate evolution up to very high redshift ($z \ge 4$).

astro-ph.GA↗

arXiv2021

BAT AGN Spectroscopic Survey XXVII: Scattered X-Ray Radiation in Obscured Active Galactic Nuclei

Accreting supermassive black holes (SMBHs), also known as active galactic nuclei (AGN), are generally surrounded by large amounts of gas and dust. This surrounding material reprocesses the primary X-ray emission produced close to the SMBH and gives rise to several components in the broadband X-ray spectra of AGN, including a power-law possibly associated with Thomson-scattered radiation. In this work, we study the properties of this scattered component for a sample of 386 hard-X-ray-selected, nearby ($z \sim 0.03$) obscured AGN from the 70-month Swift/BAT catalog. We investigate how the fraction of Thomson-scattered radiation correlates with different physical properties of AGN, such as line-of-sight column density, X-ray luminosity, black hole mass, and Eddington ratio. We find a significant negative correlation between the scattering fraction and the column density. Based on a large number of spectral simulations, we exclude the possibility that this anti-correlation is due to degeneracies between the parameters. The negative correlation also persists when considering different ranges of luminosity, black hole mass, and Eddington ratio. We discuss how this correlation might be either due to the angle dependence of the Thomson cross-section or to more obscured sources having a higher covering factor of the torus. We also find a positive correlation between the scattering fraction and the ratio of [OIII] $λ$5007 to X-ray luminosity. This result is consistent with previous studies and suggests that the Thomson-scattered component is associated with the narrow-line region.

astro-ph.HE↗