Search

We present a study of optically selected dual AGN with projected separations of 3--97~kpc. Using multi-wavelength (MWL) information (optical, X-rays, mid-IR), we characterized the intrinsic nuclear properties of this sample and compared them with those of isolated systems. Among the 124 X-ray detected AGN candidates, 52 appear in pairs and 72 as single X-ray sources. Through MWL analysis, we confirmed the presence of the AGN in a fraction >80\% of the detected targets in pairs (42 over 52). X-ray spectral analysis confirms the trend of increasing AGN luminosity with decreasing separation, suggesting that mergers may have contributed in triggering more luminous AGN. Through X/mid-IR ratio $vs$ X-ray colors, we estimated a fraction of Compton-thin AGN (with 10$^{22}$ cm$^{-2}$ $$10$^{24}$ cm$^{-2}$) sources. These fractions of obscured sources are larger than those found in samples of isolated AGN, confirming that pairs of AGN show higher obscuration. This trend is further confirmed by comparing the de-reddened [O\ III] emission with the observed X-ray luminosity. However, the derived fraction of Compton-thick sources in this sample at early stage of merging is lower than reported for late-merging dual-AGN samples. Comparing N$_{\rm H}$ from X-rays with that derived from E(B-V) from Narrow Line Regions, we find that the absorbing material is likely associated with the torus or the Broad Line Regions. We also explored the X-ray detection efficiency of dual-AGN candidates, finding that, when observed properly (at on-axis positions and with long exposures), X-ray data represent a powerful way to confirm and investigate dual-AGN systems., 12 pages, 4 figures. Accepted for publication in MNRAS

The authors wish to thank J.M. Torrejón for the organization of the Athena-multi-messenger Workshops, held on November 27 - 29, 2018, in Alicante, Spain and on 5 May 2020 - 6 May 2020 in videoconference., In this paper we explore the scientific synergies between Athena and some of the key multi-messenger facilities that should be operative concurrently with Athena. These facilities include LIGO A+, Advanced Virgo+ and future detectors for ground-based observation of gravitational waves (GW), LISA for space-based observations of GW, IceCube and KM3NeT for neutrino observations, and CTA for very high energy observations. These science themes encompass pressing issues in astrophysics, cosmology and fundamental physics such as: the central engine and jet physics in compact binary mergers, accretion processes and jet physics in Super-Massive Binary Black Holes (SMBBHs) and in compact stellar binaries, the equation of state of neutron stars, cosmic accelerators and the origin of Cosmic Rays (CRs), the origin of intermediate and high-Z elements in the Universe, the Cosmic distance scale and tests of General Relativity and the Standard Model. Observational strategies for implementing the identified science topics are also discussed. A significant part of the sources targeted by multi-messenger facilities is of transient nature. We have thus also discussed the synergy of Athena with wide-field high-energy facilities, taking THESEUS as a case study for transient discovery. This discussion covers all the Athena science goals that rely on follow-up observations of high-energy transients identified by external observatories, and includes also topics that are not based on multi-messenger observations, such as the search for missing baryons or the observation of early star populations and metal enrichment at the cosmic dawn with Gamma-Ray Bursts (GRBs)., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature., This research has been supported by the European Union’s Horizon 2020 programme under the AHEAD (grant agreement number 654215) and AHEAD2020 project (grant agreement n. 871158). FJC and SMN acknowledges funding under project RTI2018-096686-B-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”, and by the Unidad de Excelencia María de Maeztu, ref. MDM-2017-0765.

Ultra-fast outflows (UFOs) have been detected in the high-quality X-ray spectra of a number of active galactic nuclei (AGN) with fairly high accretion rates and are thought to significantly contribute to the AGN feedback. After a decade of dedicated study, their launching mechanisms and structure are still not well understood, but variability techniques may provide useful constraints. In this work, therefore, we perform a flux-resolved X-ray spectroscopy on a highly accreting and variable NLS1 AGN, 1H 0707-495, using all archival XMM-Newton observations to study the structure of the UFO. We find that the wind spectral lines weaken at higher luminosities, most likely due to an increasing ionization parameter as previously found in a few similar sources. Instead, the velocity is anticorrelated with the luminosity, which is opposite to the trend observed in the NLS1 IRAS 13224-3809. Furthermore, the detection of the emission lines, which are not observed in IRAS 13224-3809, indicates a wind with a larger opening angle in 1H 0707-495, presumably due to a higher accretion rate. The emitting gas is found to remain broadly constant with the luminosity. We describe the variability of the wind with a scenario where the strong radiation extends the launch radius outwards and shields the outer emitting gas, similarly to super-Eddington compact objects, although other possible explanations are discussed. Our work provides several hints for a multi-phase outflow in 1H 0707-495., Comment: 20 pages, 9 figures, accepted for publication in MNRAS

Short presentation with the concluding remarks of the 3rd Athena Scientific Conference.

It is a posit of modern astrophysics that most galaxies host a super-massive black hole (millions to billions of times more massive than the Sun). These black holes affect the evolution of galaxies well beyond their gravitational sphere of influence (which does not extend wider than 1/1000th of a typical galaxy linear size). In turn, the evolution of galaxies affects the growth of black holes through, e.g., galaxy merging. Interacting galaxies, or galaxies with a multiple (active) nuclei are key laboratories to investigate these processes. While the extragalactic astrophysical community share a broad consensus on each of the above statements taken individually, how these feed-back loops work in the Universe, and the relative importance of various feed-back channels remain largely not understood. Furthermore, the existing samples of dual/binary/multiple active galaxies are remarkably scarce and incomplete. My talk will offer a glimpse of the recent efforts that a group of scientists in the MAGNA ("Multiple AGN Activity"; "Eat" in Roman dialect) collaboration have been undertaking to acquire large observational samples of dual/binary AGN, and to use them to inform the cosmological and "local" simulations aiming at predicting the concurrent galaxy/black hole evolution. This talk will allow you to pierce your (X-ray) view through the dusty environment of these systems. &nbsp

Ultraluminous X-ray sources (ULXs) are mainly powered by accretion in neutron stars or stellar-mass black holes. Accreting at rates exceeding the Eddington limit by factors of a few up to hundreds, radiation pressure is expected to inflate the accretion disc, and drive fast winds that have in fact been observed at significant fractions of the speed of light. Given the super-Eddington luminosity, the accretion disc will be thicker than in sub-Eddington accretors such as common active galactic nuclei and X-ray binaries, leading to a different spectral energy distribution and, possibly, a different thermal status of the wind. Here we show the first attempt to calculate the photoionization balance of the winds driven by strong radiation pressure in thick discs with a focus on ULXs hosting black holes or non-magnetic neutron stars. We find that the winds are generally in thermally stable equilibrium, but long-term variations in the accretion rate and the inclination due to precession may have significant effects on the wind appearance and stability. Our model trends can explain the observed correlation between the spectral residuals around 1 keV and the ULX spectral state. We also find a possible correlation between the spectral hardness of the ULX, the wind velocity and the ionization parameter in support of the general scenario., Comment: 17 pages, 9 figures, 5 tables, accepted for publication in MNRAS

We present a model for the broadband radio-to-$\gamma$-ray spectral energy distribution of the compact radio source, PKS 1718-649. Because of its young age (100 years) and proximity ($z=0.014$), PKS 1718-649 offers a unique opportunity to study nuclear conditions and the jet/host galaxy feedback process at the time of an initial radio jet expansion. PKS 1718-649 is one of a handful of young radio jets with $\gamma$-ray emission confirmed with the Fermi/LAT detector. We show that this $\gamma$-ray emission can be successfully explained by Inverse Compton scattering of the ultraviolet photons, presumably from an accretion flow, off non-thermal electrons in the expanding radio lobes. The origin of the X-ray emission in PKS 1718-649 is more elusive. While Inverse Compton scattering of the infrared photons emitted by a cold gas in the vicinity of the expanding radio lobes contributes significantly to the X-ray band, the data require that an additional X-ray emission mechanism is at work, e.g. a weak X-ray corona or a radiatively inefficient accretion flow, expected from a LINER type nucleus such as that of PKS 1718-649. We find that the jet in PKS 1718-649 has low power, $L_j \simeq 2.2 \times 10^{42}$ erg s$^{-1}$, and expands in an environment with density $n_0 \simeq 20$ cm$^{-3}$. The inferred mass accretion rate and gas mass reservoir within 50-100 pc are consistent with estimates from the literature obtained by tracing molecular gas in the innermost region of the host galaxy with SINFONI and ALMA., Comment: 10 pages, 2 figures, published in ApJ

The ATHENA (Advanced Telescope for High ENergy Astrophysics) mission is steadily progressing both in terms of system studies and technology developments. The mission is currently in Phase B1 and is maturing towards a successful mission adoption. This paper describes the mission status including the main accomplishments achieved during this phase in terms of convergence of system and technological aspects. An overview of the different system studies is given including the latest programmatic assumptions, emphasizing on the Mirror Assembly demonstration and the critical interfaces between the mirror and the different facilities that are being developed in tandem to the mission. The reference telescope design is also described based on the Silicon Pore Optics (SPO) technology. The main design choices are explained as well as the modelling performed to ensure that all technological and system level constraints are met from plate level all the way to the mirror assembly level. The resulting effective area performance and budgeting is briefly described and future improvements are identified.

Over recent years there has been mounting evidence that accreting supermassive black holes in active galactic nuclei (AGN) and stellar mass black holes have similar observational signatures: thermal emission from the accretion disk, X-ray corona, and relativisitic jets. Further, there have been investigations into whether or not AGN have spectral states similar to that of X-ray binaries (XRBs) and what parallels can be drawn between the two using a hardness-intensity diagram (HID). To address whether AGN jets might be related to accretion states as in XRBs, we explore whether populations of radio-AGN classified according to their radio jet morphology (Fanaroff-Riley classes I and II; FR I and II), excitation class (HERG and LERG), and radio jet linear extent (compact to giant) occupy different and distinct regions of the AGN hardness-intensity diagram (total luminosity vs. hardness). We do this by cross correlating 15 catalogs of radio galaxies with the desired characteristics from the literature with XMM Newton and Swift X-ray and ultraviolet (UV) source catalogs. We calculate the luminosity and hardness from the X-ray and UV photometry, place the sources on the AGN hardness-intensity diagram, and search for separation of populations and analogies with the XRB spectral state HID. We find that (a) FR Is and IIs, (b) HERGs and LERGs, (c) FR I-LERGs and FR II-HERGs occupy distinct areas of the HID at a statistically significant level (p-value < 0.05) and no clear evidence for population distinction between the different radio jet linear extents. The separation between FR I-LERG and FR II-HERG populations is the strongest in this work. Our results indicate that radio-loud AGN occupy distinct areas of the HID depending on the morphology and excitation class, showing strong similarities to XRBs., 24 pages with 10 figures. Accepted for publication in Astronomy & Astrophysics

Most Ultraluminous X-ray sources (ULXs) are thought to be powered by super-Eddington accretion onto stellar-mass compact objects. Accretors in this extreme regime are naturally expected to ionise copious amounts of plasma in their vicinity and launch powerful radiation-driven outflows from their discs. High spectral resolution X-ray observations (with RGS gratings onboard XMM-Newton) of a few ULXs with the best datasets indeed found complex line spectra and confirmed such extreme (0.1-0.3c) winds. However, a search for plasma signatures in a large ULX sample with a rigorous technique has never been performed, thereby preventing us from understanding their statistical properties such as the rate of occurrence, to constrain the outflow geometry and its duty cycle. We developed a fast method for automated line detection in X-ray spectra and applied it to the full RGS ULX archive, rigorously quantifying the statistical significance of any candidate lines. Collecting the 135 most significant features detected in 89 observations of 19 objects, we created the first catalogue of spectral lines detected in soft X-ray ULX spectra. We found that the detected emission lines are concentrated around known rest-frame elemental transitions and thus originate from low-velocity material. The absorption lines instead avoid these transitions, suggesting they were imprinted by blueshifted outflows. Such winds therefore appear common among the ULX population. Additionally, we found that spectrally hard ULXs show fewer line detections than soft ULXs, indicating some difference in their accretion geometry and orientation, possibly causing over-ionisation of plasma by the harder spectral energy distributions of harder ULXs., Accepted for publication in MNRAS. 22 pages, 6 figures and 3 tables

While theory and simulations indicate that galaxy mergers play an important role in the cosmological evolution of accreting black holes and their host galaxies, samples of active galactic nuclei (AGNs) in galaxies at close separations are still small. In order to increase the sample of AGN pairs, we undertook an archival project to investigate the X-ray properties of an SDSS-selected sample of 32 galaxy pairs with separations ≤150 kpc containing one optically identified AGN, which were serendipitously observed by XMM-Newton. We discovered only one X-ray counterpart among the optically classified non-active galaxies, with a weak X-ray luminosity (∼ 5 × 1041 erg s-1). 59 per cent (19 out of 32) of the AGNs in our galaxy pair sample exhibit an X-ray counterpart, covering a wide range in absorption-corrected X-ray luminosity (5 × 1041-2 × 1044 erg s-1). More than 79 per cent of these AGNs are obscured (column density NH > 1022 cm-2), with more than half thereof (i.e. about 47 per cent of the total AGN sample) being Compton-thick. AGN/no-AGN pairs are therefore more frequently X-ray obscured (by a factor ∼1.5) than isolated AGNs. When compared to a luminosity and redshift-matched sample of bona fide dual AGN, AGN/no-AGN pairs exhibit one order-of-magnitude lower X-ray column density in the same separation range (>10 kpc). A small sample (4 objects) of AGN/no-AGN pairs with sub-pc separation is all heavily obscured, driving a formal anticorrelation between the X-ray column density and the galaxy pair separation in these systems. These findings suggest that the galactic environment has a key influence on the triggering of nuclear activity in merging galaxies. © 2021 The Author(s)., SB, ADR, and EP acknowledge financial support from the Italian Space Agency under grant ASI-INAF 2017-14-H.O. MPT acknowledges support from the Spanish MCIU through grant PGC2018-098915-B-C21 cofunded with FEDER funds and from the State Agency for Research of the Spanish MCIU through the ‘Center of Excellence Severo Ochoa’ award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709) and through grant PGC2018-098915-B-C21 (MCI/AEI/FEDER, UE). Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The SDSS-III web site is http://www.sdss3.org/. SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University.

Outflows from active galactic nuclei (AGN) are one of the fundamental mechanisms by which the central supermassive black hole interacts with its host galaxy. Detected in $\ge 50\%$ of nearby AGN, these outflows have been found to carry kinetic energy that is a significant fraction of AGN power, and thereby give negative feedback to their host galaxies. To understand the physical processes that regulate them, it is important to have a robust estimate of their physical and dynamical parameters. In this review we summarize our current understanding on the physics of the ionized outflows detected in absorption in the UV and X-ray wavelength bands. We discuss the most relevant observations and our current knowledge and uncertainties in the measurements of the outflow parameters. We also discuss their origin and acceleration mechanisms. The commissioning and concept studies of large telescope missions with high resolution spectrographs in UV/optical and X-rays along with rapid advancements in simulations offer great promise for discoveries in this field over the next decade., An invited Review Article published in Nature Astronomy: https://www.nature.com/articles/s41550-020-01255-2

We present the Catalogue of High Resolution Spectra of Obscured Sources (CHRESOS) from the XMM-Newton Science Archive. It comprises the emission-line luminosities of H- and He-like transitions from C to Si, and the Fe 3C and Fe 3G L-shell ones. Here, we concentrate on the soft X-ray OVII (f) and OVIII Lyα emission lines to shed light on to the physical processes with which their formation can be related to active galactic nucleus (AGN) versus star-forming regions. We compare their luminosity with that of two other important oxygen key lines [O III]lambda 5007 Å, in the optical, and [O IV] 25.89 mu m, in the infrared (IR). We also test OVII (f) and OVIII Lyα luminosities against that of continuum bands in the IR and hard X-rays, which point to different ionization processes. We probe into those processes by analysing photoionization and collisional ionization model predictions upon our lines. We show that both scenarios can explain the formation and observed intensities of OVII (f) and OVIII Lyα. By analysing the relationships between OVII (f) and OVIII Lyα, and all other observables: [OIII]lambda 5007 Å, [O IV] 25.89 mu m emission lines, and mid-infrared (MIR) 12 mu m, far-infrared (FIR) 60 and 100 mu m, 2-10 and 14-195 keV continuum bands, we conclude that the AGN radiation field is mainly responsible of the soft X-ray oxygen excitation., Facultad de Ciencias Astronómicas y Geofísicas, Instituto de Astrofísica de La Plata

We present the results of the latest NuSTAR monitoring campaign of the Compton-thick Seyfert 2 galaxy NGC 1068, composed of four ∼50 ks observations performed between 2017 July and 2018 February to search for flux and spectral variability on time-scales from 1 to 6 months. We detect one unveiling and one eclipsing event with time-scales less than 27 and 91 d, respectively, ascribed to Compton-thick material with NH = (1.8 ± 0.8) × 1024 and ≥ (2.4 ± 0.5) × 1024 cm−2 moving across our line of sight. This gas is likely located in the innermost part of the torus or even further inward, thus providing further evidence of the clumpy structure of the circumnuclear matter in this source. Taking advantage of simultaneous Swift–XRT observations, we also detected a new flaring ULX, at a distance d ∼ 30 arcsec (i.e. ∼2 kpc) from the nuclear region of NGC 1068, with a peak X-ray intrinsic luminosity of (3.0 ± 0.4) × 1040 erg s−1 in the 2–10 keV band., AZ, SB, and GM acknowledge financial support from the Italian Space Agency under grant no. 2017-14-H.O. SB acknowledges financial support from the Italian Space Agency under grant ASI-INAF I/037/12/0. AM and GM acknowledge financial support from the Italian Space Agency under grant ASI-INAF I/037/12/0-011/13. FEB acknowledges support from CONICYT-Chile (Basal AFB-170002) and the Ministry of Economy, Development, and Tourism’s Millennium Science Initiative through grant IC120009, awarded to the Millennium Institute of Astrophysics, MAS. CR acknowledges support from the CONICYT + PAI Convocatoria Nacional subvencion a instalacion en la academia convocatoria año 2017 PAI77170080.

arXiv:2007.07260v1, [Context]: We present a ~130 ks observation of the prototypical wind-accreting, high-mass X-ray binary Vela X-1 collected with XMM-Newton at orbital phases between 0.12 and 0.28. A strong flare took place during the observation that allows us to investigate the reaction of the clumpy stellar wind to the increased X-ray irradiation., [Aims]: To examine the wind’s reaction to the flare, we performed both time-averaged and time-resolved analyses of the RGS spectrum and examined potential spectral changes., [Methods]: We focused on the high-resolution XMM-Newton RGS spectra and divided the observation into pre-flare, flare, and post-flare phases. We modeled the time-averaged and time-resolved spectra with phenomenological components and with the self-consistent photoionization models calculated via CLOUDY and XSTAR in the pre-flare phase, where strong emission lines due to resonant transitions of highly ionized ions are seen., [Results]: In the spectra, we find emission lines corresponding to K-shell transitions in highly charged ions of oxygen, neon, magnesium, and silicon as well as radiative recombination continua (RRC) of oxygen. Additionally, we observe potential absorption lines of magnesium at a lower ionization stage and features identified as iron L lines. The CLOUDY and XSTAR photoionization models provide contradictory results, either pointing towards uncertainties in theory or possibly a more complex multi-phase plasma, or both., [Conclusions]: We are able to demonstrate the existence of a plethora of variable narrow features, including the firm detection of oxygen lines and RRC that RGS enables to observe in this source for the first time. We show that Vela X-1 is an ideal source for future high-resolution missions, such as XRISM and Athena., We acknowledge support from the ESTEC Faculty Visiting Scientist Programme to VG. SB acknowledges financial support from the Italian Space Agency under grant ASI-INAF 2017-14-H.O. Work at LLNL was performed under the auspieces of the U.S. Department of Energy under contract No. DEAC52-07NA27344. SMN acknowledges funding by the Spanish Ministry MCIU under project RTI2018-096686-B-C21 (MCIU/AEI/FEDER, UE), co-funded by FEDER funds and by the Unidad de Excelencia María de Maeztu, ref. MDM2017-0765.

The X-Ray Imaging and Spectroscopy Mission (XRISM) is the successor to the 2016 Hitomi mission that ended prematurely. Like Hitomi, the primary science goals are to examine astrophysical problems with precise highresolution X-ray spectroscopy. XRISM promises to discover new horizons in X-ray astronomy. XRISM carries a 6 x 6 pixelized X-ray micro-calorimeter on the focal plane of an X-ray mirror assembly and a co-aligned X-ray CCD camera that covers the same energy band over a large field of view. XRISM utilizes Hitomi heritage, but all designs were reviewed. The attitude and orbit control system were improved in hardware and software. The number of star sensors were increased from two to three to improve coverage and robustness in onboard attitude determination and to obtain a wider field of view sun sensor. The fault detection, isolation, and reconfiguration (FDIR) system was carefully examined and reconfigured. Together with a planned increase of ground support stations, the survivability of the spacecraft is significantly improved.

X- and \(\gamma \)-ray astronomy began in the early sixties of the last century with balloons flights, sounding rocket experiment and satellites. Long before space satellite detected X- and \(\gamma \)-rays emitted by cosmic sources, scientists had known that the Universe should be producing these photons. In this chapter we provided an overview of past and present missions that has made the X- and \(\gamma \)-ray astronomy an integral part of astronomical research, and prospects of future developments.

69 pages, 21 figures. Accepted for publication in New Astronomy Reviews © 2020 Elsevier B.V., The quest for binary and dual supermassive black holes (SMBHs) at the dawn of the multi-messenger era is compelling. Detecting dual active galactic nuclei (AGN) -- active SMBHs at projected separations larger than several parsecs -- and binary AGN -- probing the scale where SMBHs are bound in a Keplerian binary -- is an observational challenge. The study of AGN pairs (either dual or binary) also represents an overarching theoretical problem in cosmology and astrophysics. The AGN triggering calls for detailed knowledge of the hydrodynamical conditions of gas in the imminent surroundings of the SMBHs and, at the same time, their duality calls for detailed knowledge on how galaxies assemble through major and minor mergers and grow fed by matter along the filaments of the cosmic web. This review describes the techniques used across the electromagnetic spectrum to detect dual and binary AGN candidates and proposes new avenues for their search. The current observational status is compared with the state-of-the-art numerical simulations and models for formation of dual and binary AGN. Binary SMBHs are among the loudest sources of gravitational waves (GWs) in the Universe. The search for a background of GWs at nHz frequencies from inspiralling SMBHs at low redshifts, and the direct detection of signals from their coalescence by the Laser Interferometer Space Antenna in the next decade, make this a theme of major interest for multi-messenger astrophysics. This review discusses the future facilities and observational strategies that are likely to significantly advance this fascinating field.© 2020 Elsevier B.V., All authors acknowledge the hospitality of the Lorentz Center for international workshops (Leiden, The Netherlands), where the idea of this work was born, and acknowledge the support of the International Space Science Institute (ISSI Bern, Switzerland), where the collaboration was originated. We thank the reviewers for having provided valuable and constructive comments that improved the clarity of the manuscript, and J.E. Barnes, L. Blecha, M. Eracleous, B.D. Farris, H. Fu, X. Liu, R. Pfeifle, L.C. Popovic, C. Ricci, S. Rodriguez, S. Tang, G. B. Taylor for their kind permission to reuse figures from their publications. ADR, CV and SB acknowledge financial support from ASI under grant ASI-INAF I/037/12/0 , and from the agreement ASI-INAF n. 2017-14-H.O . TB acknowledges support by the National Aeronautics and Space Administration under Grant No. NNX15AK84G and 80NSSC19K0319 issued through the Astrophysics Theory Program and by the Research Corporation for Science Advancement through a Cottrell Scholar Award. SF and KÉG thank the Hungarian National Research, Development, and Innovation Office ( OTKA NN110333 ) for support. KÉG was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences and by the ÚNKP-19-4 New National Excellence Program of the Ministry for Innovation and Technology. BH acknowledges financial support by the DFG grant GE625/17-1 . EL is supported by a European Union COFUND/Durham Junior Research Fellowship (under EU grant agreement no. 609412). DL acknowledges support from the European Research Council (ERC) under grant 647208 (PI Jonker). AS is supported by the ERC CoG grant 818691 (B Massive). MGi is supported by the “Programa de Atracción de Talento” of the Comunidad de Madrid grant 2018-T1/TIC-11733 for the project: “Unveiling Black Hole Winds from Space”, and by the Spanish State Research Agency (AEI) grant MDM-2017-0737 Unidad de Excelencia “María de Maeztu” - Centro de Astrobiología (INTA-CSIC). PRC and LM acknowledge support from the Swiss National Science Foundation under the Grant 200020_178949 . MC acknowledges support from the National Science Foundation (NSF) NANOGrav Physics Frontier Center, award number 1430284 . NHR acknowledges support from the BMBF Verbundforschung under FKZ: 05A17PC1 and FKZ: 05A17PC2. ZH acknowledges support from NASA grants NNX17AL82G and 80NSSC19K0149 and NSF grant 1715661 . KI acknowledges support by the Spanish MINECO under grant AYA2016-76012-C3-1-P and MDM-2014-0369 of ICCUB (Unidad de Excelencia ’María de Maeztu’). MPT acknowledges financial support from the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía ( SEV-2017-0709 ) and through the MINECO grants AYA2012-38491-C02-02 and AYA2015-63939-C2-1-P .

The properties (temperature, density, chemical composition, velocity) of hot astrophysical plasma and the physical processes affecting them (heating/cooling, turbulence, shocks, acceleration) can be probed by high resolution X-ray spectroscopy, to be complemented by high spatial resolution imaging. The paper presents a status of the ESA's Advanced Telescope for High Energy Astrophysics (Athena) mission, particularly focusing on the science performance of its two focal plane instruments for the studies of extended X-ray sources: the Wide Field Imager (WFI) and the X-ray Integral Field Unit (X-IFU). This paper then provides a brief summary of the breakthroughs expected with Athena on the astrophysics of hot plasma, building on the vast heritage of the discoveries and revolutionary results obtained by Chandra and XMM-Newton in this field. As of November 12th, 2019, Athena successfully concluded its feasibility study, and has since then moved into the definition phase, with a launch date scheduled in the early 2030s., Comment: 12 pages, 9 figures, Proceedings of the XMM-Newton 2019 science workshop "Astrophysics of hot plasma in extended X -ray sources", accepted for publication in Astronomische Nachrichten

High-resolution X-ray spectroscopy has advanced our understanding of the hot Universe by revealing physical properties like kinematics, temperature, and abundances of the astrophysical plasmas. Despite the technical and scientific achievements, the lack of scientific products at a level higher than count spectra is hampering full scientific exploitation of high-quality data. This paper introduces the Catalogue of Ionized Emission Lines Observed by the Reflection Grating Spectrometer (CIELO-RGS) onboard the XMM-Newton space observatory. The CIELO-RGS catalogue aims to facilitate the exploitation of emission features in the public RGS spectra archive, in particular, to perform the correlation between X-ray spectral diagnostics parameters with measurements at other wavelengths. This paper focuses on the methodology of catalogue generation, describing the automated line detection algorithm. A moderate sample (~2400 observations) of high-quality RGS spectra available at XMM-Newton Science Archive is used as our starting point. A list of potential emission lines is selected based on a multi-scale peak detection algorithm in a uniform and automated way without prior assumption on the underlying astrophysical model. The candidate line list is validated via spectral fitting with simple continuum and line profile models. We also compare the catalogue content with published literature results on a small number of exemplary sources. We generate a catalogue of emission lines ~12000 detected in ~1600 observations toward stars, X-ray binaries, supernovae remnants, active galactic nuclei, and groups and clusters of galaxies. For each line, we report the observed wavelength, broadening, energy and photon flux, and equivalent width, etc., accepted to A&A

We have investigated the nature and origin of the Fe K emission lines in Mrk~205 using observations with {\it Suzaku} and {\it XMM-Newton}, aiming to resolve the ambiguity between a broad emission line and multiple unresolved lines of higher ionization. We detect the presence of a narrow Fe K$\alpha$ emission line along with a broad band Compton reflection hump at energies $E>10 \rm \, keV$. These are consistent with reflected emission of hard X-ray photons off a Compton thick material of $N_{\rm H} \ge 2.15\times 10^{24} \rm cm^{-2}$. In addition we detect a partially covering ionized absorption with ionization parameter $\log(\xi/\rm erg\, cm\, s^{-1})=1.9_{-0.5}^{+0.1}$, column density $N_{\rm H}=(5.6_{-1.9}^{+2.0})\times 10^{22}\rm cm^{-2}$ and a covering factor of $0.22_{-0.06}^{+0.09}$. We detect the presence of emission arising out of ionized disk reflection contributing in the soft and the hard X-rays consistently in all the observations. We however, could not definitely ascertain the presence of a relativistically broadened Fe line in the X-ray spectra. Using relativistic reflection model, we found that the data are unable to statistically distinguish between the scenarios when the super-massive black hole is non-rotating and when it is maximally spinning. Using the disk reflection model we also find that the accretion disk of the AGN may be truncated at a distance $6R_{\rm G}, Comment: Accepted for publication in MNRAS

The observed spatial and kinematic overlap between soft X-ray emission and the Narrow Line Region (NLR) in obscured Active Galactic Nuclei (AGN) yields compelling evidence that relatively low-density gas co-exists with higher density gas on scales as large as 100s of pc. This is commonly interpreted as evidence for a constant gas pressure multiphase medium, likely produced by thermal instability. Alternatively, Radiation Pressure Compression (RPC) also leads to a density distribution, since a gas pressure (and hence density) gradient must arise within each cloud to counteract the incident ionising radiation pressure. RPC leads to a well-defined ionization distribution, and a Differential Emission Measure (DEM) distribution with a universal slope of $\sim-0.9$, weakly dependent on the gas properties and the illuminating radiation field. In contrast, a multiphase medium does not predict the form of the DEM. The observed DEMs of obscured AGN with XMM-Newton RGS spectra (the CHRESOS sample) are in striking agreement with the predicted RPC DEM, providing a clear signature that RPC is the dominant mechanism for the observed range of densities in the X-ray NLR. In contrast with the constant gas pressure multiphase medium, RPC further predicts an increasing gas pressure with decreasing ionization, which can be tested with future X-ray missions using density diagnostics., Comment: 13 pages, 8 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journal

Compact Symmetric Objects (CSOs) have been observed with Chandra and XMM-Newton to gain insights into the initial stages of a radio source evolution and probe the black hole activity at the time of relativistic outflow formation. However, there have been no CSO observations to date at the hard X-ray energies (> 10 keV), impeding our ability to robustly constrain the properties of the intrinsic X-ray emission and of the medium surrounding the young expanding jets. We present the first hard X-ray observation of a CSO performed with NuSTAR. Our target, OQ+208, is detected up to 30 keV, and thus we establish CSOs as a new class of NuSTAR sources. We analyze the NuSTAR data jointly with our new Chandra and archival XMM-Newton data and find that a young, ~250 years old, radio jet spanning the length of ~10 pc coexists with cold obscuring matter, consistent with a dusty torus, with an equivalent hydrogen column density $N_H = 10^{23}$-$10^{24}$ cm$^{-2}$. The primary X-ray emission is characterized by a photon index $\Gamma \sim 1.45$ and intrinsic 0.5-30 keV luminosity $L \sim 10^{43}$ erg s$^{-1}$. The results of our spectral modeling and broad-line optical classification of the source suggest a porous structure of the obscuring torus. Alternatively, the source may belong to the class of optically un-obscured/X-ray obscured AGN. The observed X-ray emission is too weak compared to that predicted by the expanding radio lobes model, leaving an accretion disk corona or jets as the possible origins of the X-ray emission from this young radio galaxy., Comment: 7 pages, 3 figures, ApJ, in press

Compact Symmetric Objects (CSOs) show radio features such as jets, lobes, hot spots that are contained within the central 1 kpc region of their host galaxy. Thus, they are thought to be among the progenitors of large-scale radio galaxies. A debate on whether the CSOs are compact primarily because they are young or because they are surrounded by a dense medium impacting their expansion is ongoing. Until now, attempts to discriminate between the environmental and genuine youthfulness scenarios have been inconclusive. We present a study of three CSOs selected on the basis of their puzzling X-ray absorbing properties in prior Beppo-SAX and/or Chandra X-ray Observatory data. Our new XMM-Newton observations unambiguously confirm the nature of their X-ray absorbers. Furthermore, for the first time, our X-ray data reveal the existence of a population of CSOs with intrinsic hydrogen column density $N_H > 10^{23}$ cm$^{-2}$ that is different from the population of X-ray unabsorbed CSOs. The two groups appear to be separated in the linear size vs. radio power plane. This finding suggests that a dense medium in X-ray obscured CSOs may be able to confine the radio jets. Alternatively, X-ray obscured CSOs could be seen as radio brighter than their unobscured counterparts either because they reside in a dense environment or because they have larger jet powers. Our results help constrain the origin of the X-ray emission and the location and size of the X-ray obscurer in CSOs, and indicate that the environment may play a key role during the initial expansion of a radio source., 8 pages, 4 figures, ApJ in press

Athena, a future high-energy mission, is expected to consist of a large aperture x-ray mirror with a focal length of 12 m. The mirror surface is to be coated with iridium and a low Z overcoat. To define the effective area of the x-ray telescope, the atomic scattering factors of iridium with an energy resolution less than that (2.5 eV) of the x-ray integral field unit are needed. We measured the reflectance of the silicon pore optics mirror plate coated with iridium in the energy range of 9 to 15 keV and that near the iridium L-edges in steps of 10 and 1.5 eV, respectively, at the synchrotron beamline SPring-8. The L3, L2, and L1 edges were clearly detected around 11,215, 12,824, and 13,428 eV, respectively. The measured scattering factors were 1/43 % smaller than the corresponding values reported by Henke et al., likely due to the presence of an overlayer on the iridium coating, and were consistent with those measured by Graessle et al. The angular dependence of the reflectivity measured indicates that the iridium surface was extremely smooth, with a surface roughness of 0.3 nm.

This paper is a sequel to the extensive study of warm absorber (WA) in X-rays carried out using high resolution grating spectral data from XMM-Newton satellite (WAX-I). Here we discuss the global dynamical properties as well as the energetics of the WA components detected in the WAX sample. The slope of WA density profile ($n\propto r^{-\alpha}$) estimated from the linear regression slope of ionization parameter $\xi$ and column density $N_H$ in the WAX sample is $\alpha=1.236\pm 0.034$. We find that the WA clouds possibly originate as a result of photo-ionised evaporation from the inner edge of the torus (torus wind). They can also originate in the cooling front of the shock generated by faster accretion disk outflows, the ultra-fast outflows (UFO), impinging onto the interstellar medium or the torus. The acceleration mechanism for the WA is complex and neither radiatively driven wind nor MHD driven wind scenario alone can describe the outflow acceleration. However, we find that radiative forces play a significant role in accelerating the WA through the soft X-ray absorption lines, and also with dust opacity. Given the large uncertainties in the distance and volume filling factor estimates of the WA, we conclude that the kinetic luminosity $\dot{E}_k$ of WA may sometimes be large enough to yield significant feedback to the host galaxy. We find that the lowest ionisation states carry the maximum mass outflow, and the sources with higher Fe M UTA absorption ($15-17\rm \AA$) have more mass outflow rates., Comment: Accepted for publication in the MNRAS

We report on a systematic investigation of the cold and mildly ionized gaseous baryonic metal components of our Galaxy, through the analysis of high resolution Chandra and XMM-Newton spectra of two samples of Galactic and extragalactic sources. The comparison between lines of sight towards sources located in the disk of our Galaxy and extragalactic sources, allows us for the first time to clearly distinguish between gaseous metal components in the disk and halo of our Galaxy. We find that a Warm Ionized Metal Medium (WIMM) permeates a large volume above and below the Galaxy's disk, perhaps up to the Circum-Galactic space (CGM). This halo-WIMM imprints virtually the totality of the OI and OII absorption seen in the spectra of our extragalactic targets, has a temperature of T(Halo-WIMM)=2900 +/- 900 K, a density (Halo-WIMM) = 0.023 +/- 0.009 cm-3 and a metallicity Z(Halo-WIMM) = (0.4 +/- 0.1) Z_Solar. Consistently with previous works, we also confirm that the disk of the Galaxy contains at least two distinct gaseous metal components, one cold and neutral (the CNMM: Cold Neutral Metal Medium) and one warm and mildly ionized, with the same temperature of the Halo-WIMM, but higher density ((Disk-WIMM) = 0.09 +/- 0.03 cm-3) and metallicity (Z(Disk-WIMM) = 0.8 +/- 0.1$ Z_Solar). By adopting a simple disk+sphere geometry for the Galaxy, we estimates masses of the CNMM and the total (disk + halo) WIMM of M(CNMM), Comment: 20 pages, 12 Figures, 9 Tables. Accepted my MNRAS

We present the analysis of grating spectra of the Narrow Line Seyfert 1 Galaxy IRAS 17020+4544 observed by XMM-Newton in 2004 and 2014. In a previous work on these data, we reported the discovery of a multi-component ultra-fast outflow that is capable of producing feedback in the host galaxy. We also reported the presence of a slow, multi-phase warm absorber. In this follow-up paper, we confirm that this low velocity absorber can be modeled by four layers of ionized gas. When crossing our line-of-sight, this gas presents peculiar changes along the 10-yr time scale elapsed between the two observations obtained by XMM-Newton. While two of such components are almost stationary, the other two are found inflowing and outflowing with significant variations in velocity and ionization between 2004 and 2014. The luminosity and spectral shape of the central source remain practically unvaried. We propose that the presence of the fast wind and of the variable warm absorber can be interpreted in the framework of a `shocked outflow', where the peculiar variability pattern of the low-velocity components might arise from instabilities in the shocked gas., 16 pages, 1 figure, 2 tables, accepted by ApJ

著者人数: 193名(所属. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS): 堂谷, 忠靖; 海老沢, 研; 林, 克洋; 飯塚, 亮; 井上, 芳幸; 石田, 学; 石川, 久美; 岩井, 将親; 国分, 紀秀; 小山, 志勇; 前田, 良知; 満田, 和久; 中川, 貴雄; 尾崎, 正伸; 佐藤, 悟郎; 佐藤, 理江; Simionescu, Aurora; 菅原, 泰晴; 高橋, 忠幸; 竹井, 洋; 田村, 隆幸; 田中, 靖郎; 冨田, 洋; 辻本, 匡弘; 上田, 周太朗; 渡辺, 伸; 山崎, 典子; 内田, 悠介), Accepted: 2018-09-30, 資料番号: SA1180351000

We have carried out an extensive X-ray spectral analysis of a sample of galaxies exhibiting molecular outflows (MOX sample), to characterize the X-ray properties and investigate the effect of AGN on the dynamical properties of the molecular outflows. We find that the X-ray bolometric correction $(L_{2-10\rm keV}/L_{\rm AGN})$ of these sources ranges from $\sim10^{-4.5}$ to $10^{-0.5}$, with $\sim 70\%$ of the sources below $10^{-2}$, implying a weak X-ray emission relative to the AGN bolometric luminosity ($L_{\rm AGN}$). However, the upper limit on the $2-10\rm keV$ luminosity ($L_{\rm 2-10 keV, \,12\mu m}$) obtained from $12\mu$m flux, following the correlation derived by Asmus et al., are $\sim 0.5-3$ orders of magnitude larger than the $L_{2-10\rm keV}$ values estimated using X-ray spectroscopy, implying a possibility that the MOX sources host normal AGN (not X-ray weak), and their X-ray spectra are extremely obscured. We find that both $L_{2-10\rm keV}$, and $L_{\rm AGN}$ correlates strongly with the molecular outflow velocity as well as the mass outflow rates ($\dot{M}_{\rm out}$), implying that the central AGN plays an important role in driving these massive outflows. However, we also find statistically significant positive correlations between the starburst emission and MO mass outflow rate, $L_{\rm Starburst}$ vs $\dot{M}_{\rm out}$, and $L_{0.6-2\rm keV}$ vs $\dot{M}_{\rm out}$, which implies that starbursts can generate and drive the molecular outflows. The correlations of MO velocity and $\dot{M}_{\rm out}$ with AGN luminosities are found to be stronger compared to those with the starburst luminosities. We conclude that both starbursts and AGN play crucial role in driving the large scale MO., Comment: Accepted for publication in the ApJ

We have carried out a systematic X-ray spectral analysis of a sample of low luminosity quasars (LLQSO) to investigate the nature of the central engines of these sources. The optically-selected LLQSO sample consists of close, known bright active galactic nuclei (AGN) which serves as an important link between the powerful quasars at higher redshift and local Seyfert galaxies. We find that although the bolometric luminosities of the LLQSOs are lower than those of the higher redshift quasars by almost an order of magnitude, their distribution of the Eddington rate $\lambda_{\rm Edd}$ is similar. We detect a strong anti-correlation between $\alpha_{\rm OX}$ and $L_{2500 \rm \AA}$, as has also been detected in several other quasar studies with large sample sizes, indicating that as the UV luminosity of the source increases, the X-ray luminosity decreases. We do not detect any significant neutral obscuration ($N_{\rm H} \ge10^{22}\, \rm cm^{-2}$) in the X-ray spectra of the LLQSOs, and hence rule out obscuration as a possible cause for their lower luminosity. We conclude that the central engines of the LLQSOs function similarly to those of the higher redshift quasars, and the difference is possibly because of the fact that the LLQSOs have lower black hole masses. We do not find any correlation between the molecular gas in the host galaxies and accretion states of the AGN. This indicates that the presence of molecular gas in the host galaxies of the LLQSOs does not significantly influence the instantaneous accretion rates of their SMBHs., Comment: Published in the MNRAS journal

We present an analysis of XMM-Newton spectra of the low-redshift quasar IRAS 13349+2438. The RGS spectrum shows a large number of absorption lines from two zones of warm absorption, with velocities of $\sim$-600 km s$^{-1}$, as noted by previous authors. Additionally, we find robust evidence from multiple Ly{\alpha} absorption lines for a previously undiscovered ultra-fast zone of absorption, with an outflow velocity of $-0.13\pm0.01c$. The warm absorbers and ultra-fast outflow have similar mass outflow rates, around 40% of the Eddington accretion rate, but the kinetic power is dominated by the high velocity gas, which has a power of $\sim$4% of the Eddington luminosity., Comment: 13 pages, 13 figures, accepted for publication in MNRAS

We describe a process for cross-calibrating the effective areas of X-ray telescopes that observe common targets. The targets are not assumed to be "standard candles" in the classic sense, in that the only constraint placed on the source flux is that it is the same for all instruments. We apply a technique developed by Chen et al. (submitted to J. Amer. Stat. Association) that involves a popular statistical method called shrinkage estimation, which effectively reduces the noise in disparate measurements by combining information across common observations. We can then determine effective area correction factors for each instrument that brings all observatories into the best agreement, consistent with prior knowledge of their effective areas. We have preliminary values that characterize systematic uncertainties in effective areas for almost all operational (and some past) X-ray astronomy instruments in bands covering factors of two in photon energy from 0.15 keV to 300 keV. We demonstrate the method with several data sets from Chandra and XMM-Newton.

The ASTRO-H mission was designed and developed through an international collaboration of JAXA, NASA, ESA, and the CSA. It was successfully launched on February 17, 2016, and then named Hitomi. During the in-orbit verification phase, the on-board observational instruments functioned as expected. The intricate coolant and refrigeration systems for soft X-ray spectrometer (SXS, a quantum micro-calorimeter) and soft X-ray imager (SXI, an X-ray CCD) also functioned as expected. However, on March 26, 2016, operations were prematurely terminated by a series of abnormal events and mishaps triggered by the attitude control system. These errors led to a fatal event: the loss of the solar panels on the Hitomi mission. The X-ray Astronomy Recovery Mission (or, XARM) is proposed to regain the key scientific advances anticipated by the international collaboration behind Hitomi. XARM will recover this science in the shortest time possible by focusing on one of the main science goals of Hitomi,“Resolving astrophysical problems by precise high-resolution X-ray spectroscopy”.1 This decision was reached after evaluating the performance of the instruments aboard Hitomi and the mission’s initial scientific results, and considering the landscape of planned international X-ray astrophysics missions in 2020’s and 2030’s. Hitomi opened the door to high-resolution spectroscopy in the X-ray universe. It revealed a number of discrepancies between new observational results and prior theoretical predictions. Yet, the resolution pioneered by Hitomi is also the key to answering these and other fundamental questions. The high spectral resolution realized by XARM will not offer mere refinements; rather, it will enable qualitative leaps in astrophysics and plasma physics. XARM has therefore been given a broad scientific charge: “Revealing material circulation and energy transfer in cosmic plasmas and elucidating evolution of cosmic structures and objects”. To fulfill this charge, four categories of science objectives that were defined for Hitomi will also be pursued by XARM; these include (1) Structure formation of the Universe and evolution of clusters of galaxies; (2) Circulation history of baryonic matters in the Universe; (3) Transport and circulation of energy in the Universe; (4) New science with unprecedented high resolution X-ray spectroscopy. In order to achieve these scientific objectives, XARM will carry a 6 × 6 pixelized X-ray micro-calorimeter on the focal plane of an X-ray mirror assembly, and an aligned X-ray CCD camera covering the same energy band and a wider field of view. This paper introduces the science objectives, mission concept, and observing plan of XARM.