Search

Obscuration events in type I active galactic nuclei (AGN) have been detected more frequently in recent years. The strong flux decrease in the soft X-ray band between observations has been caused by clouds with large column densities transiting our line-of-sight (LOS) and covering the central AGN. Another event has been captured in NGC 3227 at the end of 2019. We aim to determine the nature of the observed spectral variability in 2019 obscuration event. We split the two XMM-Newton observations from 2019 into timing bins of length $\sim$ 10 ks. We used the SPEX code to analyse the 0.35-10 keV EPIC-PN spectra of each timing bin. In the first observation (Obs 1), there is a strong anti-correlation between the column density ($N_H$) of the obscurer and the continuum normalisations of the X-ray power-law and soft Comptonisation components ($N_{pow}$ and $N_{comt}$, respectively). The powerlaw continuum models the hard X-rays produced by the corona, and the Comptonisation component models the soft X-ray excess and emission from the accretion disk. Through further testing we conclude that the continuum is likely to drive the observed variability, but we cannot rule out a possible contribution from NH of the obscurer if it fully transverses across the ionising source within our LOS during the observation. The ionisation parameter ($\xi$) of the obscurer is not easily constrained, and therefore it is not clear whether it varies in response to changes in ionising continuum. The second observation (Obs 2) displays a significantly lower count rate due to the combination of a high NH and covering fraction of the obscurer, and a lower continuum flux. The observed variability seen during the obscuration event of NGC 3227 in 2019 is likely driven by the continuum, but the obscurer varies at the same time, making it difficult to distinguish between the two possibilities with full certainty., Comment: 19 pages, 15 figures

Jupiter's magnetosphere is considered to be the most powerful particle accelerator in the Solar System, accelerating electrons from eV to 70 MeV and ions to GeV energies. How electromagnetic processes drive energy and particle flows, producing and removing energetic particles, is at the heart of Heliophysics. Particularly, the 2013 Decadal Strategy for Solar and Space Physics was to "Discover and characterize fundamental processes that occur both within the heliosphere and throughout the universe". The Jovian system offers an ideal natural laboratory to investigate all of the universal processes highlighted in the previous Decadal. The X-ray waveband has been widely used to remotely study plasma across astrophysical systems. The majority of astrophysical emissions can be grouped into 5 X-ray processes: fluorescence, thermal/coronal, scattering, charge exchange and particle acceleration. The Jovian system offers perhaps the only system that presents a rich catalog of all of these X-ray emission processes and can also be visited in-situ, affording the special possibility to directly link fundamental plasma processes with their resulting X-ray signatures. This offers invaluable ground-truths for astrophysical objects beyond the reach of in-situ exploration (e.g. brown dwarfs, magnetars or galaxy clusters that map the cosmos). Here, we show how coupling in-situ measurements with in-orbit X-ray observations of Jupiter's radiation belts, Galilean satellites, Io Torus, and atmosphere addresses fundamental heliophysics questions with wide-reaching impact across helio- and astrophysics. New developments like miniaturized X-ray optics and radiation-tolerant detectors, provide compact, lightweight, wide-field X-ray instruments perfectly suited to the Jupiter system, enabling this exciting new possibility., Comment: A White Paper for the 2024-2033 Solar and Space Physics (Heliophysics) Decadal Survey

A growing number of transient X-ray obscuration events in type I AGN suggest that our line-of-sight to the central engine is not always free. Multiple X-ray obscuration events have been reported in the nearby Seyfert 1.5 galaxy NGC 3227 from 2000 to 2016. In late 2019, another X-ray obscuration event was identified with Swift. Two coordinated target-of-opportunity observations with XMM-Newton, NuSTAR, and HST/COS were triggered in Nov. and Dec. 2019 to study this obscuration event. For each observation, we analyze the time-averaged X-ray spectra. We perform photoionization modeling with the SPEX code, which allows us to constrain the intrinsic continuum simultaneously with various photoionized absorption and emission components. Similar to previous transient X-ray obscuration events in NGC 3227, the one caught in late 2019 is short-lived (less than five months). If the obscurer has only one photoionized component, the two X-ray observations in late 2019 cannot be explained by the same obscurer that responds to the varying ionizing continuum. Due to the unknown geometry of the obscurer, its number density and distance to the black hole cannot be well constrained. The inferred distance covers at least two orders of magnitude, from the BLR to the dusty torus. Unlike some other X-ray obscuration events in Seyfert galaxies like NGC 5548 and NGC 3783, no prominent blueshifted broad absorption troughs were found in the 2019 HST/COS spectra of NGC 3227 when compared with archival UV spectra. This might be explained if the X-ray obscurer does not intercept our line of sight to (a significant portion of) the UV emitting region. It is not straightforward to understand the variety of the observational differences in the X-ray obscuration events observed so far. Future observations with high-quality data are needed to unveil the nature of the X-ray obscuration events. [shortend for arXiv], Comment: A&A accepted

We present results from a multiwavelength observation of Jupiter's northern aurorae, carried out simultaneously by XMM-Newton, the Hubble Space Telescope (HST), and the Hisaki satellite in September 2019. HST images captured dawn storms and injection events in the far ultraviolet aurora several times during the observation period. Magnetic reconnection occurring in the middle magnetosphere caused by internal drivers is thought to start the production of those features. The field lines then dipolarize which injects hot magnetospheric plasma from the reconnection site to enter the inner magnetosphere. Hisaki observed an impulsive brightening in the dawnside Io plasma torus (IPT) during the final appearance of the dawn storms and injection events which is evidence that a large-scale plasma injection penetrated the central IPT between 6-9 RJ (Jupiter radii). The extreme ultraviolet aurora brightened and XMM-Newton detected an increase in the hard X-ray aurora count rate, suggesting an increase in electron precipitation. The dawn storms and injections did not change the brightness of the soft X-ray aurora and they did not "switch-on" its commonly observed quasi-periodic pulsations. Spectral analysis of the X-ray aurora suggests that the precipitating ions responsible for the soft X-ray aurora were iogenic and that a powerlaw continuum was needed to fit the hard X-ray part of the spectra. The spectra coincident with the dawn storms and injections required two powerlaw continua to get good fits., Comment: 14 pages, 7 figures in main text, 6 figures in the appendices. Accepted in MNRAS 28 July 2021

From Swift monitoring of a sample of active galactic nuclei (AGN) we found a transient X-ray obscuration event in Seyfert-1 galaxy NGC 3227, and thus triggered our joint XMM-Newton, NuSTAR, and Hubble Space Telescope (HST) observations to study this event. Here in the first paper of our series we present the broadband continuum modelling of the spectral energy distribution (SED) for NGC 3227, extending from near infrared (NIR) to hard X-rays. We use our new spectra taken with XMM-Newton, NuSTAR, and HST/COS in 2019, together with archival unobscured XMM-Newton, NuSTAR, and HST/STIS data, in order to disentangle various spectral components of NGC 3227 and recover the underlying continuum. We find the observed NIR-optical-UV continuum is explained well by an accretion disk blackbody component (Tmax = 10 eV), which is internally reddened by E(B-V) = 0.45 with a Small Magellanic Cloud (SMC) extinction law. We derive the inner radius (12 Rg) and the accretion rate (0.1 solar mass per year) of the disk by modelling the thermal disk emission. The internal reddening in NGC 3227 is most likely associated with outflows from the dusty AGN torus. In addition, an unreddened continuum component is also evident, which likely arises from scattered radiation, associated with the extended narrow-line region (NLR) of NGC 3227. The extreme ultraviolet (EUV) continuum, and the 'soft X-ray excess', can be explained with a 'warm Comptonisation' component. The hard X-rays are consistent with a power-law and a neutral reflection component. The intrinsic bolometric luminosity of the AGN in NGC 3227 is about 2.2e+43 erg/s in 2019, corresponding to 3% Eddington luminosity. Our continuum modelling of the new triggered data of NGC 3227 requires the presence of a new obscuring gas with column density NH = 5e+22 cm^-2, partially covering the X-ray source (Cf = 0.6)., Comment: Accepted for publication in Astronomy & Astrophysics (A&A), 11 pages, 7 figures

Every 19 years, Saturn passes through Jupiter's 'flapping' magnetotail. Here, we report Chandra X-ray observations of Saturn planned to coincide with this rare planetary alignment and to analyse Saturn's magnetospheric response when transitioning to this unique parameter space. We analyse three Director's Discretionary Time (DDT) observations from the High Resolution Camera (HRC-I) on-board Chandra, taken on November 19, 21 and 23 2020 with the aim to find auroral and/or disk emissions. We infer the conditions in the kronian system by looking at coincident soft X-ray solar flux data from the Geostationary Operational Environmental Satellite (GOES) and Hubble Space Telescope (HST) observations of Saturn's ultraviolet (UV) auroral emissions. The large Saturn-Sun-Earth angle during this time would mean that most flares from the Earth-facing side of the Sun would not have impacted Saturn. We find no significant detection of Saturn's disk or auroral emissions in any of our observations. We calculate the 3$\sigma$ upper band energy flux of Saturn during this time to be 0.9 - 3.04 $\times$ 10$^{14}$ erg cm$^{-2}$ s$^{-1}$ which agrees with fluxes found from previous modelled spectra of the disk emissions. We conclude by discussing the implications of this non-detection and how it is imperative that the next fleet of X-ray telescope (such as Athena and the Lynx mission concept) continue to observe Saturn with their improved spatial and spectral resolution and very enhanced sensitivity to help us finally solve the mysteries behind Saturn's apparently elusive X-ray aurora., Comment: 8 pages, 3 figures, accepted for publication in MNRAS

In review of the White Papers from the Voyage 2050 process and after the public presentation of a number of these papers in October 2019 in Madrid, we as White Paper lead authors have identified a coherent science theme that transcends the divisions around which the Topical Teams are structured. This note aims to highlight this synergistic science theme and to make the Topical Teams and the Voyage 2050 Senior Committee aware of the wide importance of these topics and the broad support that they have across the worldwide science community., Comment: 5 pages, published in Frontiers in Astronomy and Space Science

We investigate the photoionised X-ray emission line regions (ELRs) within the Seyfert 2 galaxy NGC 1068, to determine if there are any characteristic changes between observations taken fourteen years apart. We compare XMM-Newton observations collected in 2000 and 2014, simultaneously fitting the reflection grating spectrometer (RGS) and EPIC-pn spectra of each epoch, for the first time, with the photoionisation model, PION, in SPEX. We find that four PION components are required to fit the majority of the emission lines in the spectra of NGC 1068, with $\log \xi=1-4$, $\log N_H>26 m^{-2}$, and $v_{out}=-100$ to $-600 kms^{-1}$ for both epochs. Comparing the ionisation state of the components shows almost no difference between the two epochs, while there is an increase in the total column density. To estimate the locations of these plasma regions from the central black hole we compare distance methods, excluding the variability arguments as there is no spectral change between observations. Although the methods are unable to constrain the distances, the locations are consistent with the narrow line region, with the possibility of the higher ionised component being part of the broad line region, but we cannot conclude this for certain. In addition, we find evidence for emission from collisionally ionised plasma, while previous analysis had suggested that collisional plasma emission was unlikely. However, although PION is unable to account for the FeXVII emission lines at 15 and 17 \AA, we do not rule out that photoexcitation is a valid processes to produce these lines too. NGC 1068 has not changed, both in terms of the observed spectra or from our modelling, within the 14 year time period between observations. This suggests that the ELRs are fairly static relative to the 14 year time frame between observations, or there is no dramatic change in the black hole variability., Comment: 19 pages, 10 figures

Context. Obscuration events caused by outflowing clumps or streams of high column density, low ionisation gas, heavily absorbing the X-ray continuum, have been witnessed in a number of Seyfert galaxies. Aims. We report on the X-ray spectral-timing analysis of the December 2016 obscuration event in NGC 3783, aimed at probing variability of the X-ray obscurer on the shortest possible timescales. The main goals of this study are to obtain independent constraints on the density, and ultimately on the distance of the obscuring gas, as well as to characterise the impact of variable obscuration on the observed X-ray spectral-timing characteristics of Seyfert galaxies. Methods. We carried out a comparative analysis of NGC 3783 during unobscured (using archival 2000-2001 XMM-Newton data) and obscured states (using XMM-Newton and NuSTAR data from the 2016 observational campaign). The timescales analysed range between ten hours and about one hour. This study was then generalized to discuss the signatures of variable obscuration in the X-ray spectral-timing characteristics of Seyfert galaxies as a function of the physical properties of the obscuring gas. Results. The X-ray obscurer in NGC 3783 is found to vary on timescales between about one hour to ten hours. This variability is incoherent with the variations of the X-ray continuum. A fast response (on timescales shorter than about 1.5 ks) of the ionisation state of the obscuring gas to the short timescale variability of the primary X-ray continuum provides a satisfactory interpretation of all the observed X-ray spectral-timing properties. This study enabled us to put independent constraints on the density and location of the obscuring gas. We found the gas to have a density of $n_{e}> 7.1 \times 10^7 \rm{cm^{-3}}$, consistent with being part of the broad line region., Comment: Accepted for publication in A&A, corrected typo in Fig. 8

Aims. Our aim is to determine the distance of the UV outflow components from the central source, their abundances and total column density, and the mechanism responsible for their observed absorption variability. Methods. We studied the UV spectra acquired during the campaign as well as from three previous epochs (2002-2010). Our main analysis tools are ionic column-density extraction techniques and photoionization models (both equilibrium and time-dependent models) based on the code Cloudy. Results. For component 1 (at -600 km/s) our findings include the following: metallicity that is roughly twice solar; a simple model based on a fixed total column-density absorber, reacting to changes in ionizing illumination that matches the different ionic column densities derived from four spectroscopic epochs spanning 13 years; and a distance of R=6+2.5-1.5 pc from the central source. Component 2 (at -1430 km/s) has shallow troughs and is at a much larger R. For component 3 (at -1880 km/s) our findings include: a similar metallicity to component 1; a photoionization-based model can explain the major features of its complicated absorption trough variability and an upper limit of 60 or 150 pc on R. This upper limit is consistent and complementary to the X-ray derived lower limit of 12 or 31 pc for R. The total column density of the UV phase is roughly 1% and 0.1% of the lower and upper ionization components of the warm absorber, respectively. Conclusions. The NGC 7469 outflow shows super-solar metallicity similar to the outflow in Mrk 279, carbon and nitrogen are twice and four times more abundant than their solar values, respectively. Similar to the NGC 5548 case, a simple model can explain the physical characteristics and the variability observed in the outflow., Comment: 11 pages, 7 figures. accepted to A&A https://doi.org/10.1051/0004-6361/201935342

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., Comment: White-Paper submitted in response to the "Voyage-2050" ESA call: cover page + 20 page text (including 16 figures) + 5 page references + list of team-members. Additional supporting authors are listed in the acknowledgment section at page 20 of the paper

This paper addresses the fundamental science question: "How does solar wind energy flow through the Earth's magnetosphere, how is it converted and distributed?". We need to understand how the Sun creates the heliosphere, and how the planets interact with the solar wind and its magnetic field, not just as a matter of scientific curiosity, but to address a clear and pressing practical problem: space weather, which can influence the performance and reliability of our technological systems, in space and on the ground, and can endanger human life and health. Much knowledge has already been acquired over the past decades, but the infant stage of space weather forecasting demonstrates that we still have a vast amount of learning to do. We can tackle this issue in two ways: 1) By using multiple spacecraft measuring conditions in situ in the magnetosphere in order to make sense of the fundamental small scale processes that enable transport and coupling, or 2) By taking a global approach to observations of the conditions that prevail throughout geospace in order to quantify the global effects of external drivers. A global approach is now being taken by a number of space missions under development and the first tantalising results of their exploration will be available in the next decade. Here we propose the next step-up in the quest for a complete understanding of how the Sun gives rise to and controls the Earth's plasma environment: a tomographic imaging approach comprising two spacecraft which enable global imaging of magnetopause and cusps, auroral regions, plasmasphere and ring current, alongside in situ measurements. Such a mission is going to be crucial on the way to achieve scientific closure on the question of solar-terrestrial interactions.

Aims. We aim to investigate and characterise the photoionised X-ray emission line regions within NGC 7469. Methods. We apply the photoionisation model, PION, within the spectral fitting code SPEX to analyse the 640 ks RGS spectrum of NGC 7469 gathered during an XMM-Newton observing campaign in 2015. Results. We find the emission line region in NGC 7469 to be multiphased, consisting of two narrow components with ionisation parameters of $\log \xi = 0.4$ and 1.6. A third, broad emission component, with a broadening velocity of $v_b \sim 1400$ km s\textsuperscript{-1} and an outflow velocity of $v_{out} \sim -4500$ km s\textsuperscript{-1}, is required to fit the residuals in the O VII triplet, at around 22 \AA. Assuming a volume filling factor of 0.1, the lower distance limits of the narrow emission line region components are estimated for the first time at 2.6 and 2.5 pc from the central black hole, whereas the broad component has an estimated lower bound distance between 0.004 to 0.03 pc, depending on the assumed plasma parameters. The collisionally ionised plasma from the star burst region in NGC 7469 has a plasma temperature of 0.32 keV and outflow velocity of $-280$ km s\textsuperscript{-1}, consistent with previous results in this campaign. In addition, we model the photoionised plasma of the warm absorber (WA) in NGC 7469, and find that it consists of three photoionised phases, with different values of $\xi$, $N_H$ and $v_{out}$. The upper bound distances of these WA components are 1.9, 0.3 and 0.6 pc, respectively, consistent with archival results. Conclusions. The environment of NGC 7469 is a complex mix of plasma winds absorbing and emitting X-rays. We find the picture painted by our results can be attributed to line emitting plasma located at distances ranging from near the black hole to the torus and beyond the ionised outflows., Comment: 17 pages, 8 figures

Our Swift monitoring program triggered two joint XMM-Newton, NuSTAR and HST observations on 11 and 21 December 2016 targeting NGC 3783, as its soft X-ray continuum was heavily obscured. Consequently, emission features, including the O VII radiative recombination continuum, stand out above the diminished continuum. We focus on the photoionized emission features in the December 2016 RGS spectra and compare them to the time-averaged RGS spectrum obtained in 2000--2001 when the continuum was unobscured. A two-phase photoionized plasma is required to account for the narrow emission features. These narrow emission features are weakly varying between 2000--2001 and December 2016. We also find a statistically significant broad emission component in the time-averaged RGS spectrum in 2000--2001. This broad emission component is significantly weaker in December 2016, suggesting that the obscurer is farther away than the X-ray broad-line region. In addition, by analyzing the archival high-resolution X-ray spectra, we find that nine photoionized absorption components with different ionization parameters and kinematics are required for the warm absorber in X-rays., Comment: accepted to A&A

To understand the nature of transient obscuring outflows in active galactic nuclei, we observed the Seyfert 1 galaxy NGC 3783 on two occasions in December 2016 triggered by Swift monitoring indicating strong soft X-ray absorption in November. We obtained ultraviolet spectra using COS on HST and optical spectra using FEROS on the MPG/ESO 2.2-m telescope that were simultaneous with X-ray spectra from XMM-Newton and NuSTAR. We find new components of broad, blue-shifted absorption associated with Ly$\alpha$, \ion{N}{v}, \ion{Si}{iv}, and \ion{C}{iv} in our COS spectra. The absorption extends from velocities near zero in the rest-frame of the host galaxy to $-6200$ $\rm km~s^{-1}$. These features appear for the first time in NGC 3783 at the same time as the heavy soft X-ray absorption seen in the XMM-Newton X-ray spectra. The X-ray absorption has a column density of $\sim 10^{23}~\rm cm^{-2}$, and it partially covers the X-ray continuum source. The X-ray absorption becomes more transparent in the second observation, as does the UV absorption. Combining the X-ray column densities with the UV spectral observations yields an ionization parameter for the obscuring gas of log $\xi =1.84^{+0.4}_{-0.2}$ $\rm erg~cm~s^{-1}$. Despite the high intensity of the UV continuum in NGC 3783, F(1470 \AA)=$8 \times 10^{-14}~\rm erg~cm^{-2}~s^{-1}~\AA^{-1}$, the well known narrow UV absorption lines are deeper than in earlier observations in unobscured states, and low ionization species such as \ion{C}{iii} appear, indicating that the narrow-line gas is more distant from the nucleus and is being shadowed by the gas producing the obscuration. Despite the high continuum flux levels in our observations of NGC 3783, moderate velocities in the UV broad line profiles have substantially diminished. We suggest that a collapse of the broad line region has led to the outburst and triggered the obscuring event., Comment: 24 pages, 29 figures, uses aa.cls. Accepted for publication in A&A, 10/29/2018

Obscuration of the continuum emission from active galactic nuclei by streams of gas with relatively high velocity (> 1000 km/s) and column density (>3E25 per m2) has been seen in a few Seyfert galaxies. This obscuration has a transient nature. In December 2016 we have witnessed such an event in NGC 3783. The frequency and duration of these obscuration events is poorly known. Here we study archival data of NGC 3783 in order to constrain this duty cycle. We use archival Chandra/NuSTAR spectra taken in August 2016. We also study the hardness ratio of all Swift XRT spectra taken between 2008-2017. In August 2016, NGC 3783 also showed evidence for obscuration. While the column density of the obscuring material is ten times lower than in December 2016, the opacity is still sufficient to block a significant fraction of the ionising X-ray and EUV photons. From the Swift hardness ratio behaviour we find several other epochs with obscuration. Obscuration with columns >1E26 per m2 may take place in about half of the time. Also in archival X-ray data taken by ASCA in 1993 and 1996 we find evidence for obscuration. Obscuration of the ionising photons in NGC 3783 occurs more frequently than previously thought. This may not always have been recognised due to low spectral resolution observations, too limited spectral bandwidth or confusion with underlying continuum variations., Comment: 9 pages, 7 figures, submitted to Astronomy and Astrophysics

We investigate the physical structure of the AGN wind in the Seyfert-1 galaxy NGC 7469 through high-resolution X-ray spectroscopy with Chandra HETGS and photoionisation modelling. Contemporaneous data from Chandra, HST, and Swift are used to model the optical-UV-X-ray continuum and determine the spectral energy distribution (SED) at two epochs, 13 years apart. For our investigation we use new observations taken in December 2015-January 2016, and historical ones taken in December 2002. We study the impact of a change in the SED shape, seen between the two epochs, on the photoionisation of the wind. The HETGS spectroscopy shows that the AGN wind in NGC 7469 consists of four ionisation components, with their outflow velocities ranging from -400 to -1800 km/s. From our modelling we find that the change in the ionising continuum shape between the two epochs results in some variation in the ionisation state of the wind components. However, for the main ions detected in X-rays, the sum of their column densities over all four components, remains in practice unchanged. For two of the four components, which are found to be thermally unstable in both epochs, we obtain 2 < r < 31 pc and 12 < r < 29 pc using the cooling and recombination timescales. For the other two thermally stable components, we obtain r < 31 pc and r < 80 pc from the recombination timescale. The results of our photoionisation modelling and thermal stability analysis suggest that the absorber components in NGC 7469 are consistent with being a thermally-driven wind from the AGN torus. Finally, from analysis of the zeroth-order ACIS/HETG data, we discover that the X-ray emission between 0.2-1 keV is spatially extended over 1.5-12". This diffuse soft X-ray emission is explained by coronal emission from the nuclear starburst ring in NGC 7469., Comment: Accepted for publication in Astronomy & Astrophysics (A&A), 14 pages, 12 figures

We conducted a multi-wavelength six-month campaign to observe the Seyfert galaxy NGC~7469, using the space-based observatories \textit{HST}, \textit{Swift}, \textit{XMM-Newton} and \textit{NuSTAR}. Here we report the results of the spectral analysis of the 7 simultaneous \textit{XMM-Newton} and \textit{NuSTAR} observations. The sources shows significant flux variability within each observation, but the average flux is less variable among the different pointings of our campaign. Our spectral analysis reveals a prominent narrow neutral \ion{Fe} K$\alpha$ emission line in all the spectra, with weaker contributions from Fe K$\beta$, neutral Ni K$\alpha$ and ionised iron. We find no evidence for variability or relativistic effects acting on the emission lines, which indicates that they originate from distant material. Analysing jointly \textit{XMM-Newton} and \textit{NuSTAR} data a constant photon index is found ($\Gamma$=$1.78\pm0.02$), together with a high energy cut-off $E_{\rm{cut}}=170^{+60}_{-40}$ keV. Adopting a self-consistent Comptonization model, these values correspond to an average coronal electron temperature of kT=$45^{+15}_{-12}$ keV and, assuming a spherical geometry, an optical depth $\tau=2.6\pm0.9$. The reflection component is consistent with being constant, with a reflection fraction in the range $R=0.3-0.6$. A prominent soft excess dominates the spectra below 4 keV. This is best fit with a second Comptonization component, arising from a \virg{warm corona} with an average $kT=0.67\pm0.03$ keV and a corresponding optical depth $\tau=9.2\pm0.2$., Comment: 11 pages, 5 figures, accepted by A&A

The X-ray narrow emission line region (NELR) of the archetypal Seyfert 1 galaxy NGC\,5548 has been interpreted as a single-phase photoionized plasma that is absorbed by some of the warm absorber components. This scenario requires those overlaying warm absorber components to have larger distance (to the central engine) than the X-ray NELR, which is not fully consistent with the distance estimates found in the literature. Therefore, we reanalyze the high-resolution spectra obtained in 2013--2014 with the Reflection Grating Spectrometer (RGS) aboard \textit{XMM}-Newton to provide an alternative interpretation of the X-ray narrow emission features. We find that the X-ray narrow emission features in NGC\,5548 can be described by a two-phase photoionized plasma with different ionization parameters ($\log \xi=1.3$ and $0.1$) and kinematics ($v_{\rm out}=-50$ and $-400~{\rm km~s^{-1}}$), and no further absorption by the warm absorber components. The X-ray and optical NELR might be the same multi-phase photoionized plasma. Both X-ray and optical NELR have comparable distances, asymmetric line profiles, and the underlying photoionized plasma is turbulent and compact in size. The X-ray NELR is not the counterpart of the UV/X-ray absorber outside the line of sight because their distances and kinematics are not consistent. In addition, X-ray broad emission features that we find in the spectrum can be accounted for by a third photoionized emission component. The RGS spectrum obtained in 2016 is analyzed as well, where the luminosity of most prominent emission lines (the \ion{O}{vii} forbidden line and \ion{O}{viii} Ly$\alpha$ line) are the same (at a 1 $\sigma$ confidence level) as in 2013--2014., Comment: accepted for publication in A&A

We investigate the ionic column density variability of the ionized outflows associated with NGC$\sim$7469, to estimate their location and power. This could allow a better understanding of galactic feedback of AGNs to their host galaxies. Analysis of seven XMM-Newton grating observations from 2015 is reported. We use an individual-ion spectral fitting approach, and compare different epochs to accurately determine variability on time-scales of years, months, and days. We find no significant column density variability in a 10 year period implying that the outflow is far from the ionizing source. The implied lower bound on the ionization equilibrium time, 10 years, constrains the lower limit on the distance to be at least 12 pc, and up to 31 pc, much less but consistent with the 1 kpc wide starburst ring. The ionization distribution of column density is reconstructed from measured column densities, nicely matching results of two 2004 observations, with one large high ionization parameter ($\xi$) component at $2<\log \xi<3.5$, and one at $0.5<\log \xi<1$ in cgs units. The strong dependence of the expression for kinetic power, $\propto1/\xi$, hampers tight constraints on the feedback mechanism of outflows with a large range in ionization parameter, which is often observed and indicates a non-conical outflow. The kinetic power of the outflow is estimated here to be within 0.4 and 60 \% of the Eddington luminosity, depending on the ion used to estimate $\xi$., Comment: 13 pages, 9 Figures

In 2016 we carried out a Swift monitoring program to track the X-ray hardness variability of eight type-I AGN over a year. The purpose of this monitoring was to find intense obscuration events in AGN, and thereby study them by triggering joint XMM-Newton, NuSTAR, and HST observations. We successfully accomplished this for NGC 3783 in December 2016. We found heavy X-ray absorption produced by an obscuring outflow in this AGN. As a result of this obscuration, interesting absorption features appear in the UV and X-ray spectra, which are not present in the previous epochs. Namely, the obscuration produces broad and blue-shifted UV absorption lines of Ly$\alpha$, C IV, and N V, together with a new high-ionisation component producing Fe XXV and Fe XXVI absorption lines. In soft X-rays, only narrow emission lines stand out above the diminished continuum as they are not absorbed by the obscurer. Our analysis shows that the obscurer partially covers the central source with a column density of few $10^{23}$ cm$^{-2}$, outflowing with a velocity of few thousand km s$^{-1}$. The obscuration in NGC 3783 is variable and lasts for about a month. Unlike the commonly-seen warm-absorber winds at pc-scale distances from the black hole, the eclipsing wind in NGC 3783 is located at about 10 light days. Our results suggest the obscuration is produced by an inhomogeneous and clumpy medium, consistent with clouds in the base of a radiatively-driven disk wind at the outer broad-line region of the AGN., Comment: Accepted for publication in Astronomy & Astrophysics (A&A), 6 pages, 6 figures

Athena is the large mission selected by ESA in 2013 to investigate the science theme "Hot and Energetic Universe" and presently scheduled for launch in 2028. One of the two instruments located at the focus of the 12 m-long Athena telescope is the X-ray Integral Field Unit (X-IFU). This is an array of TES micro-calorimeters that will be operated at temperatures of 50 mK in order to perform high resolution spectroscopy with an energy resolution down to 2.5 eV at energies < 7 keV. In order to cope with the large dynamical range of X-ray fluxes spanned by the celestial objects Athena will be observing, the X-IFU will be equipped with a filter wheel. This will allow the user to fine tune the instrument set-up based on the nature of the target, thus optimizing the scientific outcomes of the observation. A few positions of the filter wheel will also be used to host a calibration source and to allow the measurement of the instrument intrinsic background., Comment: Proceedings of the SPIE, 2016, Paper No. 9905-189

NGC 1365 is a Seyfert 2 galaxy with a starburst ring in its nuclear region. In this work we look at the XMM Reflection Grating Spectrometer (RGS) data from four 2012-13, three 2007 and two 2004 observations of NGC 1365. We characterise the narrow-line emitting gas visible by XMM RGS and make comparisons between the 2012-13 spectra and those from 2004-07, already published. This source is usually absorbed within the soft X-ray band, with a typical neutral column density of >1.5 x 10$^{23}$ cm$^{-2}$, and only 1 observation of the 9 we investigate shows low enough absorption for the continuum to emerge in the soft X-rays. We stack all observations from 2004-07, and separately three of the four observations from 2012-13, analysing the less absorbed observation separately. We first model the spectra using gaussian profiles representing the narrow line emission. We fit physically motivated models to the 2012-13 stacked spectra, with collisionally ionised components representing the starburst emission and photoionised line emission models representing the AGN line emission. The collisional and photoionised emission line models are fitted together on top of a physical continuum and absorption model. The X-ray narrow emission line spectrum of NGC 1365 is well represented by a combination of two collisionally ionised and three photoionised phases of emitting gas, all with higher than solar nitrogen abundances. This physical model was fitted to the 2012-13 stacked spectrum, and yet also fits well to the 2004-07 stacked spectrum, without changing any characteristics of the emitting gas phases. Our 2004-07 results are consistent with previous emission line work using these data, with 5 additional emission lines detected in both this and the 2012-13 stacked spectra. We also estimate the distance of the X-ray line-emitting photoionised gas from the central source to be <300 pc., Comment: 16 pages, 8 figures. Accepted for publication in Astronomy and Astrophysics

We model the broad emission lines present in the optical, UV and X-ray spectra of Mrk 509, a bright type 1 Seyfert galaxy. The broad lines were simultaneously observed during a large multiwavelength campaign, using the XMM-Newton-OM for the optical lines, HST-COS for the UV lines and XMM-Newton-RGS and Epic for the X-ray lines respectively. We also used FUSE archival data for the broad lines observed in the far-ultra-violet. The goal is to find a physical connection among the lines measured at different wavelengths and determine the size and the distance from the central source of the emitting gas components. We used the "Locally optimally emission Cloud" (LOC) model which interprets the emissivity of the broad line region (BLR) as regulated by powerlaw distributions of both gas density and distances from the central source. We find that one LOC component cannot model all the lines simultaneously. In particular, we find that the X-ray and UV lines likely may originate in the more internal part of the AGN, at radii in the range ~5x10^{14}-3x10^{17} cm, while the optical lines and part of the UV lines may likely be originating further out, at radii ~3x10^{17}-3x^{18} cm. These two gas components are parametrized by a radial distribution of the luminosities with a slope gamma of ~1.15 and ~1.10, respectively, both of them covering at least 60% of the source. This simple parameterization points to a structured broad line region, with the higher ionized emission coming from closer in, while the emission of the low-ionization lines is more concentrated in the outskirts of the broad line region., Comment: 10 pages, 5 figures, accepted for publication in Astronomy and Astrophysics

In 2013 we conducted a large multi-wavelength campaign on the archetypical Seyfert 1 galaxy NGC 5548. Unexpectedly, this usually unobscured source appeared strongly absorbed in the soft X-rays during the entire campaign, and signatures of new and strong outflows were present in the almost simultaneous UV HST/COS data. Here we carry out a comprehensive spectral analysis of all available XMM-Newton observations of NGC 5548 (for a total of ~763 ks) in combination with 3 simultaneous NuSTAR obs. We obtain a best-fit composed by i) a weakly varying flat (Gamma~1.5-1.7) power-law component; ii) a constant, cold reflection (FeK + continuum) component; iii) a soft excess, possibly due to thermal Comptonization; and iv) a constant, ionized scattered emission-line dominated component. Our main findings are that, during the 2013 campaign, the first 3 of these components appear to be partially covered by a heavy and variable obscurer located along the l.o.s. that is consistent with a multilayer of cold and mildly ionized gas. We characterize in detail the short timescale (~ks-to-days) spectral variability of this new obscurer, and find it is mostly due to a combination of Nh and Cf variations, on top of intrinsic power-law variations. In addition, our best-fit spectrum is left with several (but marginal) absorption features at rest-frame energies ~6.7-6.9 keV and ~8 keV, as well as a weak broad emission line feature redwards of the 6.4 keV emission line. These could indicate a more complex underlying model, e.g. a P-Cygni-type profile if allowing for a large velocity and wide-angle outflow. These findings are consistent with a picture where the obscurer represents the manifestation along the l.o.s. of a multilayer of gas that is likely outflowing at high speed, and simultaneously producing heavy obscuration and scattering in the X-rays and broad absorption features in the UV., Comment: Accepted for publication in Astronomy & Astrophysics (A&A), 19 pages, 15 figures

We present our investigation into the long-term variability of the X-ray obscuration and optical-UV-X-ray continuum in the Seyfert 1 galaxy NGC 5548. In 2013 and 2014, the Swift observatory monitored NGC 5548 on average every day or two, with archival observations reaching back to 2005, totalling about 670 ks of observing time. Both broadband spectral modelling and temporal rms variability analysis are applied to the Swift data. We disentangle the variability caused by absorption, due to an obscuring weakly-ionised outflow near the disk, from variability of the intrinsic continuum components (the soft X-ray excess and the power-law) originating from the disk and its associated coronae. The spectral model that we apply to this extensive Swift data is the global model that we derived for NGC 5548 from analysis of the stacked spectra from our multi-satellite campaign of summer 2013 (including XMM-Newton, NuSTAR and HST). The results of our Swift study show that changes in the covering fraction of the obscurer is the primary and dominant cause of variability in the soft X-ray band on timescales of 10 days to ~ 5 months. The obscuring covering fraction of the X-ray source is found to range between 0.7 and nearly 1.0. The contribution of the soft excess component to the X-ray variability is often much less than that of the obscurer, but it becomes comparable when the optical-UV continuum flares up. We find that the soft excess is consistent with being the high-energy tail of the optical-UV continuum and can be explained by warm Comptonisation: up-scattering of the disk seed photons in a warm, optically thick corona as part of the inner disk. To this date, the Swift monitoring of NGC 5548 shows that the obscurer has been continuously present in our line of sight for at least 4 years (since at least February 2012)., Comment: Accepted for publication in Astronomy & Astrophysics (A&A), 12 pages, 10 figures

(Abridged) The archetypal Seyfert 1 galaxy NGC 5548 was observed in 2013-2014 in the context of an extensive multiwavelength campaign, which revealed the source to be in an extraordinary state of persistent heavy obscuration. We re-analyzed the archival grating spectra obtained by XMM-Newton and Chandra between 1999 and 2007 in order to characterize the classic warm absorber (WA) using consistent models and up-to-date photoionization codes and atomic physics databases and to construct a baseline model that can be used as a template for the WA in the 2013 observations. The WA in NGC 5548 is composed of 6 distinct ionization phases outflowing in 4 kinematic regimes in the form of a stratified wind with several layers intersected by our line of sight. If the changes in the WA are solely due to ionization or recombination processes in response to variations in the ionizing flux among the different observations, we are able to estimate lower limits on the density of the WA, finding that the farthest components are less dense and have a lower ionization. These limits are used to put stringent upper limits on the distance of the WA components from the central ionizing source, with the lowest ionization phases <50, <20, and <5 pc, respectively, while the intermediately ionized components lie at <3.6 and <2.2 pc from the center, respectively. The highest ionization component is located at ~0.6 pc or closer to the AGN central engine. The mass outflow rate summed over all WA components is ~0.3 Msun/yr, about six times the nominal accretion rate of the source. The total kinetic luminosity injected into the ISM is a small fraction (~0.03%) of the bolometric luminosity of the source. After adding the contribution of the UV absorbers, this value augments to ~0.2% of the bolometric luminosity, well below the minimum amount of energy required by current feedback models to regulate galaxy evolution., Comment: 20 pages, 8 figures, 7 tables, plus 4 figures and 6 tables in the Appendix. Accepted for publication in Astronomy & Astrophysics

Context. Our consortium performed an extensive multi-wavelength campaign of the nearby Seyfert 1 galaxy NGC 5548 in 2013-14. The source appeared unusually heavily absorbed in the soft X-rays, and signatures of outflowing absorption were also present in the UV. He-like triplets of neon, oxygen and nitrogen, and radiative recombination continuum (RRC) features were found to dominate the soft X-ray spectrum due to the low continuum flux. Aims. Here we focus on characterising these narrow emission features using data obtained from the XMM-Newton RGS (770 ks stacked spectrum). Methods. We use SPEX for our initial analysis of these features. Self-consistent photoionisation models from Cloudy are then compared with the data to characterise the physical conditions of the emitting region. Results. Outflow velocity discrepancies within the O VII triplet lines can be explained if the X-ray narrow-line region (NLR) in NGC 5548 is absorbed by at least one of the six warm absorber components found by previous analyses. The RRCs allow us to directly calculate a temperature of the emitting gas of a few eV ($\sim10^{4}$ K), favouring photoionised conditions. We fit the data with a Cloudy model of log $\xi = 1.45 \pm 0.05$ erg cm s$^{-1}$, log $N_H = 22.9 \pm 0.4$ cm$^{-2}$ and log v$_{turb} = 2.25 \pm 0.5$ km s$^{-1}$ for the emitting gas; this is the first time the X-ray NLR gas in this source has been modelled so comprehensively. This allows us to estimate the distance from the central source to the illuminated face of the emitting clouds as $13.9 \pm 0.6$ pc, consistent with previous work., Comment: Accepted by A&A, 15 pages, 6 figures

During an extensive multiwavelength campaign that we performed in 2013-14 the prototypical Seyfert 1 galaxy NGC 5548 has been found in an unusual condition of heavy and persistent obscuration. The newly discovered "obscurer" absorbs most of the soft X-ray continuum along our line of sight and lowers the ionizing luminosity received by the classical warm absorber. Here we present the analysis of the high resolution X-ray spectra collected with XMM-Newton and Chandra throughout the campaign, which are suitable to investigate the variability of both the obscurer and the classical warm absorber. The time separation between these X-ray observations range from 2 days to 8 months. On these timescales the obscurer is variable both in column density and in covering fraction. This is consistent with the picture of a patchy wind. The most significant variation occurred in September 2013 when the source brightened for two weeks. A higher and steeper intrinsic continuum and a lower obscurer covering fraction are both required to explain the spectral shape during the flare. We suggest that a geometrical change of the soft X-ray source behind the obscurer cause the observed drop in the covering fraction. Due to the higher soft X-ray continuum level the September 2013 Chandra spectrum is the only X ray spectrum of the campaign where individual features of the warm absorber could be detected. The spectrum shows absorption from Fe-UTA, \ion{O}{iv}, and \ion{O}{v}, consistent to belong to the lower-ionization counterpart of the historical NGC 5548 warm absorber. Hence, we confirm that the warm absorber has responded to the drop in the ionizing luminosity caused by the obscurer., Comment: 13 pages, 9 figures, accepted for publication in A&A

An extensive multi-satellite campaign on NGC 5548 has revealed this archetypal Seyfert-1 galaxy to be in an exceptional state of persistent heavy absorption. Our observations taken in 2013-2014 with XMM-Newton, Swift, NuSTAR, INTEGRAL, Chandra, HST and two ground-based observatories have together enabled us to establish that this unexpected phenomenon is caused by an outflowing stream of weakly ionised gas (called the obscurer), extending from the vicinity of the accretion disk to the broad-line region. In this work we present the details of our campaign and the data obtained by all the observatories. We determine the spectral energy distribution of NGC 5548 from near-infrared to hard X-rays by establishing the contribution of various emission and absorption processes taking place along our line of sight towards the central engine. We thus uncover the intrinsic emission and produce a broadband continuum model for both obscured (average summer 2013 data) and unobscured ($<$ 2011) epochs of NGC 5548. Our results suggest that the intrinsic NIR/optical/UV continuum is a single Comptonised component with its higher energy tail creating the 'soft X-ray excess'. This component is compatible with emission from a warm, optically-thick corona as part of the inner accretion disk. We then investigate the effects of the continuum on the ionisation balance and thermal stability of photoionised gas for unobscured and obscured epochs., Comment: Accepted for publication in A&A, 19 pages, 13 figures

(Abridged) Our deep multiwavelength campaign on NGC 5548 revealed an unusually strong X-ray obscuration. The resulting dramatic decrease in incident ionizing flux allowed us to construct a comprehensive physical, spatial and temporal picture for the long-studied AGN wind in this object. Here we analyze the UV spectra of the outflow acquired during the campaign as well as from four previous epochs. We find that a simple model based on a fixed total column-density absorber, reacting to changes in ionizing illumination, matches the very different ionization states seen in five spectroscopic epochs spanning 16 years. Absorption troughs from C III* appeared for the first time during our campaign. From these troughs, we infer that the main outflow component is situated at 3.5+-1 pc from the central source. Three other components are situated between 5-70 pc and two are further than 100 pc. The wealth of observational constraints and the disparate relationship of the observed X-ray and UV flux between different epochs make our physical model a leading contender for interpreting trough variability data of quasar outflows., Comment: Submitted to A&A, 13 pages and 7 figures, plus 27 pages of 3 appendix figures

We present in this paper the results of a 270 ks Chandra HETGS observation in the context of a large multiwavelength campaign on the Seyfert galaxy Mrk 509. The HETGS spectrum allows us to study the high ionisation warm absorber and the Fe-K complex in Mrk 509. We search for variability in the spectral properties of the source with respect to previous observations in this campaign, as well as for evidence of ultra-fast outflow signatures. The Chandra HETGS X-ray spectrum of Mrk 509 was analysed using the SPEX fitting package. We confirm the basic structure of the warm absorber found in the 600 ks XMM-Newton RGS observation observed three years earlier, consisting of five distinct ionisation components in a multikinematic regime. We find little or no variability in the physical properties of the different warm absorber phases with respect to previous observations in this campaign, except for component D2 which has a higher column density at the expense of component C2 at the same outflow velocity (-240 km/s). Contrary to prior reports we find no -700 km/s outflow component. The O VIII absorption line profiles show an average covering factor of 0.81 +/- 0.08 for outflow velocities faster than -100 km/s, similar to those measured in the UV. This supports the idea of a patchy wind. The relative metal abundances in the outflow are close to proto-solar. The narrow component of the Fe Kalpha emission line shows no changes with respect to previous observations which confirms its origin in distant matter. The narrow line has a red wing that can be interpreted to be a weak relativistic emission line. We find no significant evidence of ultra-fast outflows in our new spectrum down to the sensitivity limit of our data., Comment: 12 pages, 9 figures, accepted for publication in Astronomy & Astrophysics

Supermassive black holes in the nuclei of active galaxies expel large amounts of matter through powerful winds of ionized gas. The archetypal active galaxy NGC 5548 has been studied for decades, and high-resolution X-ray and UV observations have previously shown a persistent ionized outflow. An observing campaign in 2013 with six space observatories shows the nucleus to be obscured by a long-lasting, clumpy stream of ionized gas never seen before. It blocks 90% of the soft X-ray emission and causes simultaneous deep, broad UV absorption troughs. The outflow velocities of this gas are up to five times faster than those in the persistent outflow, and at a distance of only a few light days from the nucleus, it may likely originate from the accretion disk., Comment: 25 pages, 8 figures. This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science, electronically available at Science Express (June 19, 2014). For a brief video explaining the key results of this paper, please visit http://www.issibern.ch/teams/ngc5548/?page_id=25

Active Galactic Nuclei (AGN) are the most luminous persistent objects in the universe. An excess of X-ray emission below about 2 keV, called soft-excess, is very common in Type 1 AGN spectra. The origin of this feature remains debated. Originally modeled with a blackbody, there are now several possibilities to model the soft-excess, including warm Comptonization and blurred ionized reflection. In this paper, we test ionized-reflection models on Mrk 509, a bright Seyfert 1 galaxy for which we have a unique data set, in order to determine whether it can be responsible for the strong soft-excess. We use ten simultaneous XMM-Newton and INTEGRAL observations performed every four days. We present here the results of the spectral analysis, the evolution of the parameters and the variability properties of the X-ray emission. The application of blurred ionized-reflection models leads to a very strong reflection and an extreme geometry, but fails to reproduce the broad-band spectrum of Mrk 509. Two different scenarios for blurred ionized reflection are discussed: stable geometry and lamp-post configuration. In both cases we find that the model parameters do not follow the expected relations, indicating that the model is fine-tuned to fit the data without physical justification. A large, slow variation of the soft-excess without counterpart in the hard X-rays could be explained by a change in ionization of the reflector. However, such a change does not naturally follow from the assumed geometrical configuration. Warm Comptonization remains the most probable origin of the soft-excess in this object. Nevertheless, it is possible that both ionized reflection and warm Comptonization mechanisms can explain the soft-excess in all objects, one dominating the other one, depending on the physical conditions of the disk and the corona., Comment: 12 pages, A&A accepted

The Advanced Telescope for High-energy Astrophysics (Athena+) is being proposed to ESA as the L2 mission (for a launch in 2028) and is specifically designed to answer two of the most pressing questions for astrophysics in the forthcoming decade: How did ordinary matter assemble into the large scale structures we see today? and how do black holes grow and shape the Universe? For addressing these two issues, Athena+ will provide transformational capabilities in terms of angular resolution, effective area, spectral resolution, grasp, that will make it the most powerful X-ray observatory ever flown. Such an observatory, when opened to the astronomical community, will be used for virtually all classes of astrophysical objects, from high-z gamma-ray bursts to the closest planets in our solar neighborhood. In this paper, we briefly review the core science objectives of Athena+, present the science requirements and the foreseen implementation of the mission, and illustrate its transformational capabilities compared to existing facilities., Comment: 7 pages, 4 figures, to appear in the Proceedings of French Astronomical Society Meeting (SF2A-2013): L. Cambresy, F. Martins, E. Nuss and A. Palacios (eds). All information related to Athena+, including the full list of white paper contributors and Athena+ supporters (1178 as of today) can be found on the Athena+ web site: http://www.the-athena-x-ray-observatory.eu

The high resolution non-dispersive spectroscopy and unprecedented sensitivity of Athena+ will revolutionize solar system observing: the origin of the ions producing Jupiter's X-ray aurorae via charge exchange will be conclusively established, as well as their dynamics, giving clues to their acceleration mechanisms. X-ray aurorae on Saturn will be searched for to a depth unattainable by current Earth-bound observatories. The X-ray Integral Field Unit of Athena+ will map Mars' expanding exosphere, which has a line-rich solar wind charge exchange spectrum, under differing solar wind conditions and through the seasons; relating Mars' X-ray emission to its atmospheric loss will have significant impact also on the study of exoplanet atmospheres. Spectral mapping of cometary comae, which are spectacular X-ray sources with extremely line-rich spectra, will probe solar wind composition and speed at varying distances from the Sun. Athena+ will provide unique contributions also to exoplanetary astrophysics. Athena+ will pioneer the study of ingress/eclipse/egress effects during planetary orbits of hot-Jupiters, and will confirm/improve the evidence of Star-Planet Interactions (SPI) in a wider sample of planetary systems. Finally Athena+ will drastically improve the knowledge of the X-ray incident radiation on exoplanets, a key element for understanding the effects of atmospheric mass loss and of the chemical and physical evolution of planet atmospheres, particularly relevant in the case of young systems., Comment: Supporting paper for the science theme "The Hot and Energetic Universe" to be implemented by the Athena+ X-ray observatory (http://www.the-athena-x-ray-observatory.eu). 8 pages, 6 figures

(Abridged) The simultaneous UV to X-rays/gamma rays data obtained during the multi-wavelength XMM/INTEGRAL campaign on the Seyfert 1 Mrk 509 are used in this paper and tested against physically motivated broad band models. Each observation has been fitted with a realistic thermal comptonisation model for the continuum emission. Prompted by the correlation between the UV and soft X-ray flux, we use a thermal comptonisation component for the soft X-ray excess. The UV to X-rays/gamma-rays emission of Mrk 509 can be well fitted by these components. The presence of a relatively hard high-energy spectrum points to the existence of a hot (kT~100 keV), optically-thin (tau~0.5) corona producing the primary continuum. On the contrary, the soft X-ray component requires a warm (kT~1 keV), optically-thick (tau~15) plasma. Estimates of the amplification ratio for this warm plasma support a configuration close to the "theoretical" configuration of a slab corona above a passive disk. An interesting consequence is the weak luminosity-dependence of its emission, a possible explanation of the roughly constant spectral shape of the soft X-ray excess seen in AGNs. The temperature (~ 3 eV) and flux of the soft-photon field entering and cooling the warm plasma suggests that it covers the accretion disk down to a transition radius $R_{tr}$ of 10-20 $R_g$. This plasma could be the warm upper layer of the accretion disk. On the contrary the hot corona has a more photon-starved geometry. The high temperature ($\sim$ 100 eV) of the soft-photon field entering and cooling it favors a localization of the hot corona in the inner flow. This soft-photon field could be part of the comptonised emission produced by the warm plasma. In this framework, the change in the geometry (i.e. $R_{tr}$) could explain most of the observed flux and spectral variability., Comment: 19 pages, 14 figures. Accepted for publication in A&A

We report on a detailed study of the Fe K emission/absorption complex in the nearby, bright Seyfert 1 galaxy Mrk 509. The study is part of an extensive XMM-Newton monitoring consisting of 10 pointings (~60 ks each) about once every four days, and includes also a reanalysis of previous XMM-Newton and Chandra observations. Mrk 509 shows a clear (EW=58 eV) neutral Fe Kalpha emission line that can be decomposed into a narrow (sigma=0.027 keV) component (found in the Chandra HETG data) plus a resolved (sigma=0.22 keV) component. We find the first successful measurement of a linear correlation between the intensity of the resolved line component and the 3-10 keV flux variations on time-scales of years down to a few days. The Fe Kalpha reverberates the hard X-ray continuum without any measurable lag, suggesting that the region producing the resolved Fe Kalpha component is located within a few light days-week (r<~10^3 rg) from the Black Hole (BH). The lack of a redshifted wing in the line poses a lower limit of >40 rg for its distance from the BH. The Fe Kalpha could thus be emitted from the inner regions of the BLR, i.e. within the ~80 light days indicated by the Hbeta line measurements. In addition to these two neutral Fe Kalpha components, we confirm the detection of weak (EW~8-20 eV) ionised Fe K emission. This ionised line can be modeled with either a blend of two narrow FeXXV and FeXXVI emission lines or with a single relativistic line produced, in an ionised disc, down to a few rg from the BH. Finally, we observe a weakening/disappearing of the medium and high velocity high ionisation Fe K wind features found in previous XMM-Newton observations. This campaign has made possible the first reverberation measurement of the resolved component of the Fe Kalpha line, from which we can infer a location for the bulk of its emission at a distance of r~40-1000 rg from the BH., Comment: Accepted for publication in A&A

The bright Seyfert 1 galaxy Mrk 509 was monitored by XMM-Newton and other satellites in 2009 to constrain the location of the outflow. We have studied the response of the photoionised gas to changes in the ionising flux produced by the central regions. We used the 5 discrete ionisation components A-E detected in the time-averaged spectrum taken with the RGS. Using the ratio of fluxed EPIC and RGS spectra, we put tight constraints on the variability of the absorbers. Monitoring with the Swift satellite started 6 weeks before the XMM-Newton observations, allowing to use the ionising flux history and to develop a model for the time-dependent photoionisation. Components A and B are too weak for variability studies, but the distance for component A is known from optical imaging of the [O III] line to be ~3 kpc. During the 5 weeks of the XMM-Newton observations we found no evidence of changes in the 3 X-ray dominant ionisation components C-E, despite a huge soft X-ray intensity increase of 60% in the middle of our campaign. This excludes high-density gas close to the black hole. Instead, using our time-dependent modelling, we find low density and derive firm lower limits to the distance of these components. Component D shows evidence for variability on longer time scales, yielding an upper limit to the distance. For component E we derive an upper limit to the distance based on the argument that the thickness of the absorbing layer must be less than its distance to the black hole. Combining these results, at the 90% confidence level, component C has a distance of >70 pc, component D between 5-33 pc, and component E >5 pc but smaller than 21-400 pc, depending upon modelling details. These results are consistent with the upper limits from the HST/COS observations of our campaign and point to an origin of the dominant, slow (v<1000 km/s) outflow components in the NLR or torus-region of Mrk 509., Comment: 17 pages, 16 figures, accepted for publication in Astronomy and Astrophysics

We observed Mrk 509 during the fall of 2009 during a multiwavelength campaign using XMM-Newton, Chandra, HST/COS, SWIFT, and Integral. The 600-ks XMM/RGS spectrum finds two kinematic components and a discrete distribution of ionized absorbers. Our high S/N COS spectrum detects additional complexity in the known UV absorption troughs from a variety of sources in Mrk 509, including the outflow from the active nucleus, the ISM and halo of the host galaxy, and infalling clouds or stripped gas from a merger that are illuminated by the AGN. The UV absorption only partially covers the emission from the AGN nucleus with covering fractions lower than those previously seen with STIS, and are comparable to those seen with FUSE. Given the larger apertures of COS and FUSE compared to STIS, we favor scattered light from an extended region near the AGN as the explanation for the partial covering. As observed in prior X-ray and UV spectra, the UV absorption has velocities comparable to the X-ray absorption, but the bulk of the ultraviolet absorption is in a lower ionization state with lower total column density than the gas responsible for the X-ray absorption. Variability compared to prior UV spectra lets us set limits on the location, density, mass flux, and kinetic energy of the outflowing gas. For component 1 at $-400 \rm km s^{-1}$, the kinetic energy flux of both the UV and the X-ray outflow is insufficient to have a significant impact on further evolution of the host galaxy., Comment: 5 pages, to be published in the proceedings of the conference "AGN Winds in Charleston", October 2011

Context. The study of abundances in the nucleus of active galaxies allows us to investigate the evolution of abundance by comparing local and higher redshift galaxies. However, the methods used so far have substantial drawbacks or rather large uncertainties. Some of the measurements are at odds with the initial mass function derived from the older stellar population of local elliptical galaxies. Aims. We determine accurate and reliable abundances of C, N, Ne, and Fe relative to O from the narrow absorption lines observed in the X-ray spectra of Mrk 509. Methods. We use the stacked 600 ks XMM-Newton RGS and 180 ks Chandra LETGS spectra. Thanks to simultaneous observations with INTEGRAL and the optical monitor on-board XMM-Newton for the RGS observations and HST-COS and Swift for the LETGS observations, we have an individual spectral energy distribution for each dataset. Owing to the excellent quality of the RGS spectrum, the ionisation structure of the absorbing gas is well constrained, allowing for a reliable abundance determination using ions over the whole observed range of ionisation parameters. Results. We find that the relative abundances are consistent with the proto-solar abundance ratios: C/O = 1.19$\pm$0.08, N/O = 0.98$\pm$0.08, Ne/O = 1.11$\pm$0.10, Mg/O = 0.68$\pm$0.16, Si/O = 1.3$\pm$0.6, Ca/O = 0.89$\pm$0.25, and Fe/O = 0.85$\pm$0.06, with the exception of S, which is slightly under-abundant, S/O = 0.57$\pm$0.14. Our results, and their implications, are discussed and compared to the results obtained using other techniques to derive abundances in galaxies., Comment: 10 pages, accepted for publication by A&A

We present here the results of a 180 ks Chandra-LETGS observation as part of a large multi-wavelength campaign on Mrk 509. We study the warm absorber in Mrk 509 and use the data from a simultaneous HST-COS observation in order to assess whether the gas responsible for the UV and X-ray absorption are the same. We analyzed the LETGS X-ray spectrum of Mrk 509 using the SPEX fitting package. We detect several absorption features originating in the ionized absorber of the source, along with resolved emission lines and radiative recombination continua. The absorption features belong to ions with, at least, three distinct ionization degrees. The lowest ionized component is slightly redshifted (v = +73 km/s) and is not in pressure equilibrium with the others, and therefore it is not likely part of the outflow, possibly belonging to the interstellar medium of the host galaxy. The other components are outflowing at velocities of -196 and -455 km/s, respectively. The source was observed simultaneously with HST-COS, finding 13 UV kinematic components. At least three of them can be kinematically associated with the observed X-ray components. Based on the HST-COS results and a previous FUSE observation, we find evidence that the UV absorbing gas might be co-located with the X-ray absorbing gas and belong to the same structure., Comment: 12 pages, 7 figures, 9 tables. Accepted for publication in Astronomy & Astrophysics

Planetary plasma and magnetic field environments can be studied by in situ measurements or by remote sensing. While the former provide precise information about plasma behaviour, instabilities and dynamics on local scales, the latter offers the global view necessary to understand the overall interaction of the magnetospheric plasma with the solar wind. Here we propose a novel and more elegant approach employing remote X-ray imaging techniques, which are now possible thanks to the relatively recent discovery of solar wind charge exchange X-ray emissions in the vicinity of the Earth's magnetosphere. We describe how an appropriately designed and located X-ray telescope, supported by simultaneous in situ measurements of the solar wind, can be used to image the dayside magnetosphere, magnetosheath and bow shock, with a temporal and spatial resolution sufficient to address several key outstanding questions concerning how the solar wind interacts with the Earth's magnetosphere on a global level. Our studies have led us to propose 'AXIOM: Advanced X-ray Imaging Of the Magnetosphere', a concept mission using a Vega launcher with a LISA Pathfinder-type Propulsion Module to place the spacecraft in a Lissajous orbit around the Earth - Moon L1 point. The model payload consists of an X-ray Wide Field Imager and an in situ plasma and magnetic field measurement package. This package comprises sensors designed to measure the bulk properties of the solar wind and to characterise its minor ion populations which cause charge exchange emission, and a magnetometer designed to measure the strength and direction of the solar wind magnetic field. We show simulations that demonstrate how the proposed X-ray telescope design is capable of imaging the predicted emission from the dayside magnetosphere with the sensitivity and cadence required to achieve the science goals of the mission., Comment: Published in Experimental Astronomy, Springer (40 pages, 14 figures, 5 tables). Updated version re-submitted to arXiv on 1 August 2011 (with corrected figure numbering and improved versions of Fig.s 4, 7, 10, 11); http://www.springerlink.com/openurl.asp?genre=article&id=doi:10.1007/s10686-011-9239-0 (published on-line, July 2011)

We present medium resolution (R~20,000) HST/COS ultraviolet spectra covering 1155-1760 A of the Seyfert 1 Mrk 509 obtained simultaneously with a Chandra/LETGS spectrum as part of a multiwavelength campaign in 2009 that included observations with XMM-Newton, SWIFT, and Integral. Our high S/N spectrum detects additional complexity in the absorption troughs from a variety of sources in Mrk 509, including the outflow from the active nucleus, the ISM and halo of the host galaxy, and infalling clouds or stripped gas from a merger that are illuminated by the AGN. Variability between the STIS and COS observation of the -400 km/s component allows us to set an upper limit on its distance of < 250 pc. Similarly, variability of a component at +150 km/s between two prior FUSE observations limits its distance to < 1.5 kpc. The UV absorption only partially covers the emission from the AGN nucleus. Covering fractions are lower than those previously seen with STIS, and are comparable to those seen with FUSE. Given the larger apertures of COS and FUSE compared to STIS, we favor scattered light from an extended region near the AGN as the explanation for the partial covering. As observed in prior X-ray and UV spectra, the UV absorption has velocities comparable to the X-ray absorption, but the bulk of the ultraviolet absorption is in a lower ionization state with lower total column density than the gas responsible for the X-ray absorption. We conclude that the outflow from the active nucleus is a multiphase wind., Comment: 21 pages, 9 figures. Accepted for publication in Astronomy & Astrophysics, 26 May 2011