arXiv subjects

F. Tombesi

Publications and source records attributed to F. Tombesi.

At least 73 records · Page 4Linked to original sources

arXiv2021

Dips and eclipses in the X-ray binary Swift J1858.6-0814 observed with NICER

We present the discovery of eclipses in the X-ray light curves of the X-ray binary Swift J1858.6-0814. From these, we find an orbital period of $P=76841.3_{-1.4}^{+1.3}$ s ($\approx21.3$ hours) and an eclipse duration of $t_{\rm ec}=4098_{-18}^{+17}$ s ($\approx1.14$ hours). We also find several absorption dips during the pre-eclipse phase. From the eclipse duration to orbital period ratio, the inclination of the binary orbit is constrained to $i>70^\circ$. The most likely range for the companion mass suggests that the inclination is likely to be closer to this value than $90^\circ$. The eclipses are also consistent with earlier data, in which strong variability ('flares') and the long orbital period prevent clear detection of the period or eclipses. We also find that the bright flares occurred preferentially in the post-eclipse phase of the orbit, likely due to increased thickness at the disc-accretion stream interface preventing flares being visible during the pre-eclipse phase. This supports the notion that variable obscuration is responsible for the unusually strong variability in Swift J1858.6-0814.

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arXiv2020

Speed limits for radiation driven SMBH winds

Ultra Fast Outflows (UFOs) are an established feature in X-ray spectra of AGNs. According to the standard picture, they are launched at accretion disc scales with relativistic velocities, up to 0.3-0.4 c. Their high kinetic power is enough to induce an efficient feedback on galactic-scale, possibly contributing to the co-evolution between the central supermassive black hole (SMBH) and the host galaxy. It is therefore of paramount importance to fully understand the UFO physics, in particular the forces driving their acceleration and the relation with the accretion flow they originate from. In this paper we investigate the impact of special relativity effects on the radiative pressure exerted onto the outflow. The radiation received by the wind decreases for increasing outflow velocity v, implying that the standard Eddington limit argument has to be corrected according to v. Due to the limited ability of the radiation to counteract the SMBH gravity, we expect to find lower typical velocities with respect to the non-relativistic scenario. We integrate the relativistic-corrected outflow equation of motion for a realistic set of starting conditions. We concentrate on UFO typical values of ionisation, column density and launching radius. We explore a one-dimensional, spherical geometry and a 3D setting with a rotating thin accretion disc. We find that the inclusion of relativistic effects leads to sizeable differences in the wind dynamics and that v is reduced up to 50% with respect to the non-relativistic treatment. We compare our results with a sample of UFO from the literature, and we find that the relativistic-corrected velocities are systematically lower than the reported ones, indicating the need for an additional mechanism, such as magnetic driving, to explain the highest velocity components. These conclusions, derived for AGN winds, have a general applicability.

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arXiv2020

Location and energetics of the ultra-fast outflow in PG 1448+273

Ultra-fast outflows (UFOs) play a key role in the AGN feedback mechanism. It is therefore important to fully characterize their location and energetics. We study the UFO in the latest XMM-Newton archival observation of the NLSy1 galaxy PG 1448+273 by means of a novel modeling tool, that is, the Wind in the Ionized Nuclear Environment model (WINE). Our detection of the UFO in PG 1448+273 is very robust. The outflowing material is highly ionized, $\logξ= 5.53_{-0.05}^{+0.04}$ erg s$^{-1}$ cm, has a large column density, $N_\mathrm{H} = 4.5_{-1.1}^{+0.8} \times 10^{23}$ cm$^{-2}$, is ejected with a maximum velocity $v_0 = 0.24^{+0.08}_{-0.06}\,c$ (90% c.l. errors), and attains an average velocity $v_\mathrm{avg} = 0.152\,c$. WINE succeeds remarkably well to constrain a launching radius of $r_0=77_{-19}^{+31} \, r_\mathrm{S}$ from the black hole. We also derive a lower limit on both the opening angle of the wind ($θ> 72^{\circ}$) and the covering factor ($C_\mathrm{f} > 0.69$). We find a mass outflow rate $\dot{M}_\mathrm{out}=0.65^{+0.44}_{-0.33}\,M_\odot \mathrm{yr}^{-1} = 2.0^{+1.3}_{-1.0}\, \dot{M}_\mathrm{acc}$ and a large instantaneous outflow kinetic power $\dot{E}_\mathrm{out}=4.4^{+4.4}_{-3.6} \times 10^{44}$ erg s$^{-1}$ = 24% $L_\mathrm{bol}$ = 18% $L_\mathrm{Edd}$ ($1 σ$ errors). We find that a major error contribution on the energetics is due to $r_0$, stressing the importance of an accurate determination through a proper spectral modeling, as done with WINE. Using 20 Swift (UVOT and XRT) observations and the simultaneous OM data from XMM-Newton, we also find that $α_\mathrm{ox}$ undergoes large variations, with a maximum excursion of $Δα_\mathrm{ox} =-0.7$, after the UFO is detected, leading to a remarkable X-ray weakness. This may point towards a starving of the inner accretion disk due to the removal of matter through the wind.

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arXiv2020

Galaxy-scale ionised winds driven by ultra-fast outflows in two nearby quasars

We use MUSE adaptive optics (AO) data in Narrow Field Mode to study the properties of the ionised gas in MR 2251-178 and PG 1126-041, two nearby (z~0.06) bright quasars hosting sub-pc scale Ultra Fast Outflows (UFOs) detected in the X-ray band. We decompose the optical emission from diffuse gas into a low- and a high-velocity components. The former is characterised by a clean, regular velocity field and a low (~80 km/s) velocity dispersion. It traces regularly rotating gas in PG 1126-041, while in MR 2251-178 it is possibly associated to tidal debris from a recent merger or flyby. The other component is found to be extended up to a few kpc from the nuclei, and shows a high (~800 km/s) velocity dispersion and a blue-shifted mean velocity, as expected from AGN-driven outflows. We estimate mass outflow rates up to a few Mo/yr and kinetic efficiencies between 0.1-0.4 per cent, in line with those of galaxies hosting AGNs of similar luminosity. The momentum rates of these ionised outflows are comparable to those measured for the UFOs at sub-pc scales, consistent with a momentum-driven wind propagation. Pure energy-driven winds are excluded unless about 100x additional momentum is locked in massive molecular winds. By comparing the outflow properties of our sources with those of a small sample of well-studied QSOs hosting UFOs from the literature, we find that winds seem to systematically lie either in a momentum-driven or in an energy-driven regime, indicating that these two theoretical models bracket very well the physics of AGN-driven winds.

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arXiv2020

NICER observations reveal that the X-ray transient MAXI J1348-630 is a Black Hole X-ray binary

We studied the outburst evolution and timing properties of the recently discovered X-ray transient MAXI J1348-630 as observed with NICER. We produced the fundamental diagrams commonly used to trace the spectral evolution, and power density spectra to study the fast X-ray variability. The main outburst evolution of MAXI J1348-630 is similar to that commonly observed in black hole transients. The source evolved from the hard state, through hard- and soft-intermediate states, into the soft state in the outburst rise, and back to the hard state in reverse during the outburst decay. At the end of the outburst, MAXI J1348-630 underwent two reflares with peak fluxes ~1 and ~2 orders of magnitude fainter than the main outburst, respectively. During the reflares, the source remained in the hard state only, without undergoing any state transitions, which is similar to the so-called "failed outbursts". Different types of quasi-periodic oscillations (QPOs) are observed at different phases of the outburst. Based on our spectral-timing results, we conclude that MAXI J1348-630 is a black hole candidate.

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arXiv2020

Tracing circumnuclear dense gas in H2O maser galaxies

A sample of 30 H2O extra-galactic maser galaxies with their published HCN(J=1-0) and HCO+(J=1-0) observations has been compiled to investigate the dense gas correlation with H2O maser emission. Our sample number exceeds the size of the previous HCN samples studied so far by a factor of three, and it is the first study on the possible relation with the dense gas tracer HCO+. We find a strong correlation between normalized H2O maser emission luminosity (LH2O\LCO) and normalized HCO+ line luminosity (LHCO+\LCO). Moreover, a weak correlation has been found between LH2O\LCO and normalized HCN line luminosity (LHCN\LCO). The sample is also studied after excluding Luminous and Ultraluminous infrared galaxy (U)LIRG sources, and the mentioned correlations are noticeably stronger. We show that 'Dense gas' fractions as obtained from HCN and HCO+ molecules tightly correlate with maser emission, especially for galaxies with normal IR luminosity(LIR< 10^11Lsun) and we show that HCO+ is a better 'dense gas' tracer than HCN. Further systematic studies of these dense gas tracers with higher transition level lines are vital to probe megamaser physical conditions and to accurately determining how maser emission interrelates with the dense gas.

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arXiv2020

Discovery of thermonuclear (Type I) X-ray bursts in the X-ray binary Swift J1858.6-0814 observed with NICER and NuSTAR

Swift J1858.6-0814 is a recently discovered X-ray binary notable for extremely strong variability (by factors $>100$ in soft X-rays) in its discovery state. We present the detection of five thermonuclear (Type I) X-ray bursts from Swift J1858.6-0814, implying that the compact object in the system is a neutron star. Some of the bursts show photospheric radius expansion, so their peak flux can be used to estimate the distance to the system. The peak luminosity, and hence distance, can depend on several system parameters; for the most likely values, a high inclination and a helium atmosphere, $D=12.8_{-0.6}^{+0.8}$ kpc, although systematic effects allow a conservative range of $9-18$ kpc. Before one burst, we detect a QPO at $9.6\pm0.5$ mHz with a fractional rms amplitude of $2.2\pm0.2$% ($0.5-10$ keV), likely due to marginally stable burning of helium; similar oscillations may be present before the other bursts but the light curves are not long enough to allow their detection. We also search for burst oscillations but do not detect any, with an upper limit in the best case of 15% fractional amplitude (over $1-8$ keV). Finally, we discuss the implications of the neutron star accretor and this distance on other inferences which have been made about the system. In particular, we find that Swift J1858.6-0814 was observed at super-Eddington luminosities at least during bright flares during the variable stage of its outburst.

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arXiv2020

The Impact of Tidal Disruption Events on Galactic Habitability

Tidal Disruption Events (TDEs) are characterized by the emission of a short burst of high-energy radiation. We analyze the cumulative impact of TDEs on galactic habitability using the Milky Way as a proxy. We show that X-rays and extreme ultraviolet (XUV) radiation emitted during TDEs can cause hydrodynamic escape and instigate biological damage. By taking the appropriate variables into consideration, such as the efficiency of atmospheric escape and distance from the Galactic center, we demonstrate that the impact of TDEs on galactic habitability is comparable to that of Active Galactic Nuclei. In particular, we show that planets within distances of $\sim 0.1$-$1$ kpc could lose Earth-like atmospheres over the age of the Earth, and that some of them might be subject to biological damage once every $\gtrsim 10^4$ yrs. We conclude by highlighting potential ramifications of TDEs and argue that they should be factored into future analyses of inner galactic habitability.

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arXiv2020

X-ray Spectral and Timing evolution of MAXI J1727-203 with NICER

We present a detailed X-ray spectral and variability study of the full 2018 outburst of MAXI J1727-203 using NICER observations. The outburst lasted approximately four months. Spectral modelling in the 0.3-10 keV band shows the presence of both a soft thermal and a hard Comptonised component. The analysis of these components shows that MAXI J1727-203 evolved through the soft, intermediate and hard spectral states during the outburst. We find that the soft (disc) component was detected throughout almost the entire outburst, with temperatures ranging from ~0.4 keV, at the moment of maximum luminosity, to ~0.1 keV near the end of the outburst. The power spectrum in the hard and intermediate states shows broadband noise up to 20 Hz, with no evidence of quasi-periodic oscillations. We also study the rms spectra of the broadband noise at 0.3-10 keV of this source. We find that the fractional rms increases with energy in most of the outburst except during the hard state, where the fractional rms remains approximately constant with energy. We also find that, below 3 keV, the fractional rms follows the same trend generally observed at energies >3 keV, a behaviour known from previous studies of black holes and neutron stars. The spectral and timing evolution of MAXI J1727-203, as parametrised by the hardness-intensity, hardness-rms, and rms-intensity diagrams, suggest that the system hosts a black hole, although we could not rule out a neutron star.

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arXiv2020

A NICER look at the state transitions of the black hole candidate MAXI J1535-571 during its reflares

The black hole candidate and X-ray binary MAXI J1535-571 was discovered in September 2017. During the decay of its discovery outburst, and before returning to quiescence, the source underwent at least four reflaring events, with peak luminosities of $\sim$10$^{35-36}$ erg s$^{-1}$ (d/4.1 kpc)$^2$. To investigate the nature of these flares, we analysed a sample of NICER observations taken with almost daily cadence. In this work we present the detailed spectral and timing analysis of the evolution of the four reflares. The higher sensitivity of NICER at lower energies, in comparison with other X-ray detectors, allowed us to constrain the disc component of the spectrum at $\sim$0.5 keV. We found that during each reflare the source appears to trace out a q-shaped track in the hardness-intensity diagram similar to those observed in black hole binaries during full outbursts. MAXI J1535-571 transits between the hard state (valleys) and softer states (peaks) during these flares. Moreover, the Comptonised component is undetected at the peak of the first reflare, while the disc component is undetected during the valleys. Assuming the most likely distance of 4.1 kpc, we find that the hard-to-soft transitions take place at the lowest luminosities ever observed in a black hole transient, while the soft-to-hard transitions occur at some of the lowest luminosities ever reported for such systems.

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arXiv2020

Hard - X-rays selected Active Galactic Nuclei. I. A radio view at high-frequencies

A thorough study of radio emission in Active Galactic Nuclei (AGN) is of fundamental importance to understand the physical mechanisms responsible for the emission and the interplay between accretion and ejection processes. High frequency radio observations can target the nuclear contribution of smaller emitting regions and are less affected by absorption. We present JVLA 22 and 45 GHz observations of 16 nearby (0.003$\le$z$\le$0.3) hard - X-rays selected AGN at the (sub)-kpc scale with tens uJy beam$^{-1}$ sensitivity. We detected 15/16 sources, with flux densities ranging from hundreds uJy beam$^{-1}$ to tens Jy (specific luminosities from $\sim$10$^{20}$ to $\sim$10$^{25}\,W\,Hz^{-1}$ at 22 GHz). All detected sources host a compact core, with 8 being core-dominated at either frequencies, the others exhibiting also extended structures. Spectral indices range from steep to flat/inverted. We interpret this evidence as either due to a core+jet system (6/15), a core accompanied by surrounding star formation (1/15), to a jet oriented close to the line of sight (3/15), to emission from a corona or the base of a jet (1/15), although there might be degeneracies between different processes. Four sources require more data to shed light on their nature. We conclude that, at these frequencies, extended, optically-thin components are present together with the flat-spectrum core. The ${L_R}/{L_X}\sim10^{-5}$ relation is roughly followed, indicating a possible contribution to radio emission from a hot corona. A weakly significant correlation between radio core (22 and 45 GHz) and X-rays luminosities is discussed in the light of an accretion-ejection framework.

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arXiv2020

Linking Macro, Meso, and Micro Scales in Multiphase AGN Feeding and Feedback

Supermassive black hole (SMBH) feeding and feedback processes are often considered as disjoint and studied independently at different scales, both in observations and simulations. We encourage to adopt and unify three physically-motivated scales for feeding and feedback (micro - meso - macro ~ mpc - kpc - Mpc), linking them in a tight multiphase self-regulated loop. We pinpoint the key open questions related to this global SMBH unification problem, while advocating for the extension of novel mechanisms best observed in massive halos (such as chaotic cold accretion) down to low-mass systems. To solve such challenges, we provide a set of recommendations that promote a multiscale, multiwavelength, and interdisciplinary community.

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arXiv2020

A broadband X-ray view of the NLSy1 1E 0754.6+392.8

The soft X-ray band of many active galactic nuclei (AGNs) is affected by obscuration due to partially ionised matter crossing our line of sight. In this context, two past XMM-Newton observations (6 months apart) and a simultaneous NuSTAR-Swift ($\sim$8 years later) exposure of the Narrow Line Seyfert 1 galaxy 1E 0754.6+392.8 revealed an intense and variable WA and hints of additional absorbers in the Fe K$α$ band. We present the first X-ray characterisation of this AGN discussing its broadband (0.3-79 keV) spectrum and temporal properties. We conduct a temporal and spectroscopic analysis on two $\sim$10 ks (net exposure) XMM-Newton snapshots performed in April and October 2006. We also study the high energy behaviour of 1E 0754.6+392.8 modelling its broadband spectrum using simultaneous Swift-NuSTAR data. Both phenomenological and physically motivated models are tested. We find the presence of flux variability ($\sim$150% and 30% for 0.3-2 and 2-10 keV bands, respectively) and spectral changes at months timescales ($ΔΓ\sim$0.4). A reflection component that is consistent with being constant over years and arising from relatively cold material far from the central super massive black hole is detected. The main spectral feature shaping the 1E 0754.6+392.8 spectrum is a warm absorber. Such a component is persistent over the years and variability of its ionisation and column density is observed down on months in the ranges 3$\times10^{22} \rm cm^{-2}\lesssim$ N$_{\rm{H}}\lesssim7.2\times10^{22} \rm cm^{-2}$ and 1.5 $\lesssim\log(ξ/{\rm erg~s^{-1}~cm})\lesssim$2.1. Despite the short exposures, we find possible evidence of two additional highly ionised and high-velocity outflow components in absorption. Longer exposures are mandatory in order to characterise the complex outflow in this AGN.

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arXiv2019

On the importance of special relativistic effects in modelling ultra-fast outflows

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.

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arXiv2019

The X-ray Halo Scaling Relations of Supermassive Black Holes

We carry out a comprehensive Bayesian correlation analysis between hot halos and direct masses of supermassive black holes (SMBHs), by retrieving the X-ray plasma properties (temperature, luminosity, density, pressure, masses) over galactic to cluster scales for 85 diverse systems. We find new key scalings, with the tightest relation being the $M_\bullet-T_{\rm x}$, followed by $M_\bullet-L_{\rm x}$. The tighter scatter (down to 0.2 dex) and stronger correlation coefficient of all the X-ray halo scalings compared with the optical counterparts (as the $M_\bullet-σ_{\rm e}$) suggest that plasma halos play a more central role than stars in tracing and growing SMBHs (especially those that are ultramassive). Moreover, $M_\bullet$ correlates better with the gas mass than dark matter mass. We show the important role of the environment, morphology, and relic galaxies/coronae, as well as the main departures from virialization/self-similarity via the optical/X-ray fundamental planes. We test the three major channels for SMBH growth: hot/Bondi-like models have inconsistent anti-correlation with X-ray halos and too low feeding; cosmological simulations find SMBH mergers as sub-dominant over most of the cosmic time and too rare to induce a central-limit-theorem effect; the scalings are consistent with chaotic cold accretion (CCA), the rain of matter condensing out of the turbulent X-ray halos that sustains a long-term self-regulated feedback loop. The new correlations are major observational constraints for models of SMBH feeding/feedback in galaxies, groups, and clusters (e.g., to test cosmological hydrodynamical simulations), and enable the study of SMBHs not only through X-rays, but also via the Sunyaev-Zel'dovich effect (Compton parameter), lensing (total masses), and cosmology (gas fractions).

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arXiv2019

The Voyage of Metals in the Universe from Cosmological to Planetary Scales: the need for a Very High-Resolution, High Throughput Soft X-ray Spectrometer

Metals form an essential part of the Universe at all scales. Without metals we would not exist, and the Cosmos would look completely different. Metals are primarily born through nuclear processes in stars. They leave their cradles through winds or explosions, and then start their journey through space. This can lead them in and out of astronomical objects on all scales, ranging from comets, planets, stars, entire galaxies, groups and clusters of galaxies to the largest structures of the Universe. Their wanderings are fundamental in determining how these objects, and the entire universe, evolve. In addition, their bare presence can be used to trace what these structures look like. The scope of this paper is to highlight the most important open astrophysical problems that will be central in the next decades and for which a deep understanding of the Universe-wandering metals, their physical and kinematical states and their chemical composition represents the only viable solution. The majority of these studies can only be efficiently performed through High Resolution Spectroscopy in the soft X-ray band.

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arXiv2019

The WISSH quasars project VI. Fraction and properties of BAL quasars in the hyper-luminosity regime

The WISSH quasars project aims at studying the nuclear and host galaxy properties of the most luminous quasars ($L_{bol}>10^{47}$ erg/s, $1.8<z<4.6$). Nuclear winds are manifested as UV broad ($\geq$ 2,000 km/s) absorption lines (BAL) in $\sim$ 15\% of quasars. We aim at studying the incidence and properties of such winds in the WISSH sample, to investigate possible differences with respect to lower luminosity AGN regimes. We collected optical spectra from the SDSS data release 12, and identified those showing absorption troughs in the region between \siiv and \civ emission lines. We find a higher observed fraction of \civ BAL quasars in the WISSH sample (24\%) with respect to previous catalogues (10-15\%). These WISSH BAL quasars are also characterized by a larger average BI ($\sim$4,000 km/s) and maximum velocity ($\sim$17,000 km/s). Moreover, for two objects we discovered BAL features bluewards of the \siiv peak, which can be associated to \civ absorption with velocity of 0.15c. Finally, we updated previous studies on the dependence of maximum outflow velocity upon bolometric luminosity, showing that BAL winds have intermediate properties compared to molecular/ionized winds and ultra fast outflows (UFOs). Finally, the radio properties of the WISSH BAL quasars as a whole are in line with those of samples at lower luminosities from previous studies. Our results suggest that the higher $L_{\rm bol}$ of the WISSH quasars likely favours the acceleration of BAL outflows and that their most likely driving mechanism is radiation pressure. Furthermore we estimate that the kinetic power associated to these winds in hyperluminous quasars is sufficient, for the highest column density and fastest winds, to provide efficient feedback onto the host galaxy.

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arXiv2019

Exploring the multiphase medium in MKW 08: from the central active galaxy up to cluster scales

The study of the brightest cluster galaxy (BCG) coronae embedded in noncool core (NCC) galaxy clusters is crucial to understand the BCG's role in galaxy cluster evolution as well as the activation of the self-regulated cooling and heating mechanism in the central regions of galaxy clusters. We explore the X-ray properties of the intracluster medium (ICM) of the NCC galaxy cluster MKW 08 and the BCG corona, along with their interface region. With recent and deep archival Chandra observations, we study the BCG corona in detail, and with archival XMM-Newton observations, we investigate the implications of the central active galactic nuclei (AGN) on the BCG. We carry out imaging and spectral analyses of MKW 08 with archival XMM-Newton and Chandra X-ray observations. Our spectral analysis suggests the presence of a central AGN by a power-law with a photon index of $Γ$ ~ 1.8 at the core of its BCG. Although the ICM does not exhibit a cluster scale cool core, the BCG manifests itself as a mini cool core characterized by a cooling time as short as 64 Myr at r = 3 kpc centered at the galaxy. The isothermality of the BCG corona seems to favor mechanical feedback from the central AGN as the major source of gas heating. The gas pressure profile of this mini cool core suggests that the BCG coronal gas reaches pressure equilibrium with the hotter and less dense ICM inside an interface of nearly constant pressure, delimited by radii 4 < r < 10 kpc at the galactic center. As revealed by the presence of a metal enriched tail (Z ~ 0.5 - 0.9 Solar) extending up to 40 kpc, the BCG corona seems to be experiencing ram-pressure stripping by the surrounding ICM and/or interacting with a nearby galaxy, IC 1042.}

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