The EPIC focal plane imaging spectrometers on XMM-Newton use CCDs to record the images and spectra of celestial X-ray sources focused by the three X-ray mirrors. There is one camera at the focus of each mirror; two of the cameras contain seven MOS CCDs, while the third uses twelve PN CCDs, dening a circular eld of view of 30 0 diameter in each case. The CCDs were specially developed for EPIC, and combine high quality imaging with spectral resolution close to the Fano limit. A lter wheel carrying three kinds of X-ray transparent light blocking lter, a fully closed, and a fully open position, is tted to each EPIC instrument. The CCDs are cooled passively and are under full closed loop thermal control. A radio-active source is tted for internal calibration. Data are processed on-board to save telemetry by removing cosmic ray tracks, and generating X-ray event les; a variety of dierent instrument modes are available to increase the dynamic range of the instrument and to enable fast timing. The instruments were calibrated using laboratory X-ray beams, and synchrotron generated monochromatic X-ray beams before launch; in-orbit calibration makes use of a variety of celestial X-ray targets. The current calibration is better than 10% over the entire energy range of 0.2 to 10 keV. All three instruments survived launch and are performing nominally in orbit. In particular full eld-of-view coverage is available, all electronic modes work, and the energy resolution is close to pre-launch values. Radiation damage is well within pre-launch predictions and does not yet impact on the energy resolution. The scientic results from EPIC amply full pre-launch expectations.

/pdf/the-european-photon-imaging-camera-on-xmm-newton-the-mos-250n8v72zu.pdf

The European Photon Imaging Camera on XMM-Newton: The MOS cameras

The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the ~10 keV high-energy cutoff achieved by all previous X-ray satellites. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity over the collimated or coded mask instruments that have operated in this bandpass. Using its unprecedented combination of sensitivity and spatial and spectral resolution, NuSTAR will pursue five primary scientific objectives: (1) probe obscured active galactic nucleus (AGN) activity out to the peak epoch of galaxy assembly in the universe (at z ≾ 2) by surveying selected regions of the sky; (2) study the population of hard X-ray-emitting compact objects in the Galaxy by mapping the central regions of the Milky Way; (3) study the non-thermal radiation in young supernova remnants, both the hard X-ray continuum and the emission from the radioactive element ^(44)Ti; (4) observe blazars contemporaneously with ground-based radio, optical, and TeV telescopes, as well as with Fermi and Swift, to constrain the structure of AGN jets; and (5) observe line and continuum emission from core-collapse supernovae in the Local Group, and from nearby Type Ia events, to constrain explosion models. During its baseline two-year mission, NuSTAR will also undertake a broad program of targeted observations. The observatory consists of two co-aligned grazing-incidence X-ray telescopes pointed at celestial targets by a three-axis stabilized spacecraft. Deployed into a 600 km, near-circular, 6° inclination orbit, the observatory has now completed commissioning, and is performing consistent with pre-launch expectations. NuSTAR is now executing its primary science mission, and with an expected orbit lifetime of 10 yr, we anticipate proposing a guest investigator program, to begin in late 2014.

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THE NUCLEAR SPECTROSCOPIC TELESCOPE ARRAY (NuSTAR) HIGH-ENERGY X-RAY MISSION

Many problems in the experimental estimation of parameters for models can be solved through use of the likelihood ratio test. Applications of the likelihood ratio, with particular attention to photon counting experiments, are discussed. The procedures presented solve a greater range of problems than those currently in use, yet are no more difficult to apply. The procedures are proved analytically, and examples from current problems in astronomy are discussed.

Parameter estimation in astronomy through application of the likelihood ratio. [satellite data analysis techniques

Quasinormal modes are eigenmodes of dissipative systems. Perturbations of classical gravitational backgrounds involving black holes or branes naturally lead to quasinormal modes. The analysis and classification of the quasinormal spectra require solving non-Hermitian eigenvalue problems for the associated linear differential equations. Within the recently developed gauge-gravity duality, these modes serve as an important tool for determining the near-equilibrium properties of strongly coupled quantum field theories, in particular their transport coefficients, such as viscosity, conductivity and diffusion constants. In astrophysics, the detection of quasinormal modes in gravitational wave experiments would allow precise measurements of the mass and spin of black holes as well as new tests of general relativity. This review is meant as an introduction to the subject, with a focus on the recent developments in the field.

/pdf/quasinormal-modes-of-black-holes-and-black-branes-3f4tq2403g.pdf

Quasinormal modes of black holes and black branes

After the All-Sky Automated Survey for SuperNovae discovered a significant brightening of the inner region of NGC 2617, we began a ∼70 day photometric and spectroscopic monitoring campaign from the X-ray through near-infrared (NIR) wavelengths. We report that NGC 2617 went through a dramatic outburst, during which its X-ray flux increased by over an order of magnitude followed by an increase of its optical/ultraviolet (UV) continuum flux by almost an order of magnitude. NGC 2617, classified as a Seyfert 1.8 galaxy in 2003, is now a Seyfert 1 due to the appearance of broad optical emission lines and a continuum blue bump. Such 'changing look active galactic nuclei (AGNs)' are rare and provide us with important insights about AGN physics. Based on the Hβ line width and the radius-luminosity relation, we estimate the mass of central black hole (BH) to be (4 ± 1) × 10{sup 7} M {sub ☉}. When we cross-correlate the light curves, we find that the disk emission lags the X-rays, with the lag becoming longer as we move from the UV (2-3 days) to the NIR (6-9 days). Also, the NIR is more heavily temporally smoothed than the UV. This can largely be explained bymore » a simple model of a thermally emitting thin disk around a BH of the estimated mass that is illuminated by the observed, variable X-ray fluxes.« less

https://iopscience.iop.org/article/10.1088/0004-637X/788/1/48/pdf

The man behind the curtain: x-rays drive the uv through nir variability in the 2013 active galactic nucleus outburst in ngc 2617

The XMM-Newton Observatory is a cornerstone mission of the European Space Agency's Horizon 2000 programme, and is the largest scientific satellite it has launched to date. This paper summarises the principal characteristics of the Observatory which are pertinent to scientific operations. The scientific results appearing in this issue have been enabled by the unprecedentedly large effective area of the three mirror modules, which are briefly described. The in-orbit performance and preliminary calibrations of the observatory are briefly summarised. The observations from the XMM-Newton calibration and performance verification phase, which are public and from which most papers in this issue have been derived, are listed. The flow of data from the spacecraft, through the ground segment, to the production of preliminary science products supplied to users is also discussed.

https://www.aanda.org/articles/aa/pdf/2001/01/aaxmm39.pdf

XMM-Newton observatory. I. The spacecraft and operations

Aims. We present CAIXA, a Catalogue of AGN In the XMM-Newton Archive. It consists of all the radio-quiet X-ray unobscured (N H < 2 × 10 22 cm -2 ) active galactic nuclei (AGN) observed by XMM-Newton in targeted observations, whose data are public as of March 2007. With its 156 sources, this is the largest catalogue of high signal-to-noise X-ray spectra of AGN. Methods. All the EPIC pn spectra of the sources in CAIXA were extracted homogeneously, and a baseline model was applied in order to derive their basic X-ray properties. These data are complemented by multiwavelength data found in the literature: black hole masses, full width half maximum (FWHM) of Hβ, radio and optical fluxes. Results. Here we describe our homogeneous spectral analysis of the X-ray data in CAIXA and present all the results on the parameters adopted in our best-fit models.

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CAIXA: a Catalogue of AGN In the XMM-Newton Archive I. Spectral analysis

Context. We report on the results of the first XMM-Newton systematic "excess variance" study of all the radio quiet, X-ray un-obscured AGN. The entire sample consist of 161 sources observed by XMM-Newton for more than 10 ks in pointed observations, which is the largest sample used so far to study AGN X-ray variability on time scales less than a day. Aims. Recently it has been suggested that the same engine might be at work in the core of every black hole (BH) accreting object. In this hypothesis, the same variability should be observed in all AGN, once rescaled by the MBH (MBH) and accretion rate (m). Methods. We systematically compute the excess variance for all AGN, on different time-scales (10, 20, 40 and 80 ks) and in different energy bands (0.3-0.7, 0.7-2 and 2-10 keV). Results. We observe a highly significant and tight (~0.7 dex) correlation between σ2rms and MBH. The subsample of reverberation mapped AGN shows an even smaller scatter (only a factor of 2-3) comparable to the one induced by the MBH uncertainties. This implies that X-ray variability can be used as an accurate tool to measure MBH and this method is more accurate than the ones based on single epoch optical spectra. This allows us to measure MBH for 65 AGN and estimate lower limits for the remaining 96 AGN. On the other hand, the σ2rms vs. accretion rate dependence is weaker than expected based on the PSD break frequency scaling. This strongly suggests that both the PSD high frequency break and the normalisation depend on accretion rate in such a way that they almost completely counterbalance each other (PSDamp ∝ m-0.8). A highly significant correlation between σ2rms and 2-10 keV spectral index is observed. The highly significant correlations between σ2rms and both the LBol and the FWHMHβ are consistent with being just by-products of the σ2rms vs. MBH relation. The soft and medium σ2rms is very well correlated with the hard σ2rms, with no deviations from a linear one to one correlation. This suggests that the additional soft components (i.e. soft excess, warm absorber) add a minor contribution to the total variability. Once the variability is rescaled for MBH and m, no significant difference between narrow-line and broad-line Seyfert 1 is observed. Conclusions. The results are in agreement with a picture where, to first approximation, all local AGN have the same variability properties once rescaled for MBH and m.

/pdf/caixa-a-catalogue-of-agn-in-the-xmm-newton-archive-iii-1hfwebr2u1.pdf

CAIXA: a catalogue of AGN in the XMM-Newton archive - III. Excess variance analysis

We report performance verification observations of the giant elliptical galaxy M87 in the Virgo Cluster with the MOS, pn, and optical monitor instruments on board of XMM-Newton. With the energy sensitive imaging instruments MOS and pn we obtain the first spatially constrained X-ray spectra of the nucleus and the jet of the galaxy. The good photon statistics of the pn and MOS allow a detailed analysis of the radial temperature and abundance distribution of 6 elements. The data provide no indication of a multi-temperature structure for radii less than 2 arcmin. An apparent sharp metal abundance drop deduced for the regions inside this radius is probably due to resonant line scattering.

/pdf/xmm-newton-observations-of-m87-and-its-x-ray-halo-50906shuro.pdf

XMM-Newton observations of M87 and Its X-Ray Halo

We discuss the properties of a small sample of Seyfert 2 galaxies whose X-ray spectrum changed appearance on time scales of years, becoming reflection-dominated from Compton-thin, or viceversa. A reflection--dominated spectrum is usually taken as evidence of Compton-thick absorption, but we instead argue that such a spectrum is due to a temporary switching--off of the nuclear radiation. The observations discussed here may help explaining mismatches between optical and X-ray classifications, and provide new strong and direct evidence of the presence of more than one cold circumnuclear region in Seyfert 2 galaxies.

https://arxiv.org/pdf/astro-ph/0302328.pdf

Matteo Guainazzi

Papers

XMM-Newton observatory. I. The spacecraft and operations

CAIXA: a Catalogue of AGN In the XMM-Newton Archive I. Spectral analysis

CAIXA: a catalogue of AGN in the XMM-Newton archive - III. Excess variance analysis

XMM-Newton observations of M87 and Its X-Ray Halo

Changing look: from Compton-thick to Compton-thin, or the re-birth of fossil AGN