Simbol-X is a French-Italian-German hard energy X-ray mission with a projected launch in 2014. Being sensitive in the
energy range from 500 eV to 80 keV it will cover the sensitivity gap beyond the energy interval of today's telescopes
XMM-Newton and Chandra. Simbol-X will use an imaging telescope of nested Wolter-I mirrors. To provide a focal
length of 20 m it will be the first mission of two independent mirror and detector spacecrafts in autonomous formation
The detector spacecraft's payload is composed of an imaging silicon low energy detector in front of a pixelated
cadmium-telluride hard energy detector. Both have a sensitive area of 8 × 8 cm<sup>2</sup> to cover a 12 arcmin field of view and a pixel size of 625 × 625 μm<sup>2</sup> adapted to the telescope's resolution of 20 arcsec. The additional LED specifications are:
high energy resolution, high quantum efficiency, fast readout and optional window mode, monolithic device with 100 %
fill factor and suspension mounting, and operation at warm temperature.
To match these requirements the low energy detector is composed of 'active macro pixels', combining the large, scalable
area of a Silicon Drift Detector and the low-noise, on-demand readout of an integrated DEPFET amplifier. Flight
representative prototypes have been processed at the MPI semiconductor laboratory, and the prototype's measured
performance demonstrates the technology readiness.
eROSITA (extended ROentgen Survey with an Imaging Telescope Array) will be one of three main instruments on the
Russian new Spectrum-RG mission which is planned to be launched in 2011. The other two instruments are the wide
field X-ray monitor Lobster (Leicester University, UK) and ART-XC (IKI, Russia), an X-ray telescope working at
higher energies up to 30 keV. A fourth instrument, a micro-calorimeter built by a Dutch-Japanese-US collaboration is
also in discussion. eROSITA is aiming primarily for the detection of 50-100 thousands Clusters of Galaxies up to
redshifts z > 1 in order to study the large scale structure in the Universe and to test cosmological models including the
Dark Energy. For the detection of clusters, a large effective area is needed at low energies (< 2 keV). Therefore,
eROSITA consists of seven Wolter-I telescope modules. Each mirror module contains 54 Wolter-I shells with an outer
diameter of 360 mm. In the focus of each mirror module, a framestore pn-CCD with a size of 3cm × 3cm provides a field
of view of 1° in diameter. The mission scenario comprises a wide survey of the complete extragalactic area and a deep
survey in the neighborhood of the galactic poles. Both are accomplished by an all-sky survey with an appropriate
orientation of the rotation axis of the satellite in order to achieve the deepest exposures in the neighborhood of the
galactic poles. A critical issue is the cooling of the cameras which need a working temperature of -80°C. This will be
achieved passively by a system of two radiators connected to the cameras by variable conductance heat pipes.
Simbol-X is a hard X-ray mission, operating in the ~ 0.5-80 keV range, proposed as a collaboration between the French
and Italian space agencies with participation of German laboratories for a launch in 2013. Relying on two spacecraft in a
formation flying configuration, Simbol-X uses for the first time a 20-30 m focal length X-ray mirror to focus X-rays
with energy above 10 keV, resulting in over two orders of magnitude improvement in angular resolution and sensitivity
in the hard X-ray range with respect to non-focusing techniques. The Simbol-X revolutionary instrumental capabilities
will allow us to elucidate outstanding questions in high energy astrophysics such as those related to black-holes accretion
physics and census, and to particle acceleration mechanisms, which are the prime science objectives of the mission.
After having undergone a thorough assessment study performed by CNES in the context of a selection of a formation
flight scientific mission, Simbol-X has been selected for a phase A study to be jointly conducted by CNES and ASI. The
mission science objectives, the current status of the instrumentation and mission design are presented in this paper.
The Simbol-X mission, currently undergoing a joint CNES-ASI phase A, is essentially a classical X-ray telescope having an exceptional large focal length obtained by formation flying technics. One satellite houses the Wolter I optics to focus, for the first time in space, X-rays above ~10 keV, onto the focal plane in the second satellite. This leads to improved angular resolution and sensitivity which are two orders of magnitude better than those obtained so far with non-focusing techniques. Tailored to the 12 arcmin field of view and ~15 arcsec angular resolution of the optics, the ~8x8 cm<sup>2</sup> detection area of the spectro-imager has ~ 500x500 <i>μ</i>m<sup>2</sup> pixels, and covers the full energy range of Simbol-X, from ~0.5 to ~80 keV, with a good energy resolution at both low and high energy. Its design leads to a very low residual background in order to reach the required sensitivity. The focal plane ensemble is made of two superposed spectro-imaging detectors: a DEPFET-SDD active pixel sensor on top of an array of pixelated Cd(Zn)Te crystals, surrounded by an appropriate combination of active and passive shielding. Besides the overall concept and structure of the focal plane including the anti-coincidence and shielding, this paper also emphasizes the promising results obtained with the active pixel sensors and the Cd(Zn)Te crystals combined with their custom IDeF-X ASICs.
eROSITA (extended ROentgen Survey with an Imaging Telescope Array) will be one out of three main instruments on
the Russian new Spectrum-RG mission which will be launched in the timeframe 2010-2011 into an equatorial Low Earth
Orbit. The other two instruments are the wide field X-ray monitor Lobster (Leicester University, UK) and ART (IKI,
Russia), an X-ray concentrator based on a Kumakhov optics. eROSITA consists of seven Wolter-I telescope modules
similar to the German mission ABRIXAS which failed in 1999 and ROSITA, a telescope which was planned to be
installed on the International Space Station ISS. Unlike these, the eROSITA telescope modules will be extended by
adding another 27 mirror shells to the already existing ABRIXAS design. This will increase the effective area by a factor
of ~5 at low energies. The additional shells do not contribute to the area at higher energies ( > 5 keV) due to the relative
large grazing angles. Here we stay with the old ABRIXAS/ROSITA effective area. However, the primary scientific goal
has changed since ABRIXAS: we are now aiming primarily for the detection of 50-100 thousands Clusters of Galaxies
up to redshifts z > 1 in order to study the large scale structure in the Universe and test cosmological models including the
Dark Energy, which was not yet known at ABRIXAS times. For the detection of clusters, a large effective area is needed
at low (< 2 kev) energies. The mission scenario comprises a wide survey of the complete extragalactic area and a deep
survey in the neighborhood of the Galactic Poles. Both are accomplished by an all-sky survey with a tilt of the rotation
axis in order to shift the deepest exposures away from the ecliptic poles towards the galactic poles.
SIMBOL-X is a hard X-ray mission, operating in the ~ 0.5-70 keV range, which is proposed by a consortium of European laboratories in response to the 2004 call for ideas of CNES for a scientific mission to be flown on a formation flying demonstrator. Relying on two spacecrafts in a formation flying configuration, SIMBOL-X uses for the first time a ~ 30 m focal length X-ray mirror to focus X-rays with energy above 10 keV, resulting in a two orders of magnitude improvement in angular resolution and sensitivity in the hard X-ray range with respect to non focusing techniques. The SIMBOL-X revolutionary instrumental capabilities will allow to elucidate outstanding questions in high energy astrophysics, related in particular to the physics of accretion onto compact objects, to the acceleration of particles to the highest energies, and to the nature of the Cosmic X-Ray background. The mission, which has gone through a thorough assessment study performed by CNES, is expected to start a competitive phase A in autumn 2005, leading to a flight decision at the end of 2006, for a launch in 2012. The mission science objectives, the current status of the instrumentation and mission design, as well as potential trade-offs are presented in this paper.
Various X-ray satellites have used the Crab as a standard candle to perform their calibrations in the past. The calibration of XMM-Newton, however, is independent of the Crab nebula, because this object has not been used to adjust spectral calibration issues. In 2004 a number of special observations were performed to measure the spectral parameters and the absolute flux of the Crab with XMM-Newton's EPIC-pn CCD camera. We describe the results of the campaign in detail and compare them with data of four current missions (Integral, Swift, Chandra, RXTE) and numerous previous missions (ROSAT, EXOSAT, Beppo-SAX, ASCA, Ginga, Einstein, Mir-HEXE).
The X-ray observatory XMM-Newton is now in orbit for more than 5 years. The performance of the EPIC-pn CCD camera has been monitored since and its calibration has been improved steadily. We report in this presentation on our recent investigations in different calibration issues: Data of the on-board Fe-55 calibration source were used for monitoring the charge transfer efficiency (CTE) degradation. A special calibration observation of the line-rich supernova remnant Cas-A in the extended Full Frame Mode was used to refine the energy calibration in this mode. Together with ground measurements, a non-routine observation of the calibration target N132D will lead to an improvement of the CTE correction of the Large Window Mode.
High quantum efficiency over a broad spectral range is one of the main properties of the EPIC pn camera on-board XMM-Newton. The quantum efficiency rises from ~75% at 0.2 keV to ~100% at 1 keV, stays close to 100% until 8 keV, and is still ~90% at 10 keV. The EPIC pn camera is attached to an X-ray telescope which has the highest collecting area currently available, in particular at low energies (more than 1400 cm2 between 0.1 and 2.0 keV). Thus, this instrument is very sensitive to the low-energy X-ray emission. However, X-ray data at energies below ~0.2 keV are considerably affected by detector effects, which become more and more important towards the lowest transmitted energies. In addition to that, pixels which have received incorrect offsets during the calculation of the offset map at the beginning of each observation, show up as bright patches in low-energy images. Here we describe a method which is not only capable of suppressing the contaminations found at low energies, but which also improves the data quality throughout the whole EPIC pn spectral range. This method is then applied to data from the Vela supernova remnant.
Dark Energy dominates the mass-energy content of the universe (about 73%) but we do not understand it. Most of the remainder of the Universe consists of Dark Matter (23%), made of an unknown particle. The problem of the origin of Dark Energy has become the biggest problem in astrophysics and one of the biggest problems in all of science. The major extant X-ray observatories, the Chandra X-ray Observatory and XMM-Newton, do not have the ability to perform large-area surveys of the sky. But Dark Energy is smoothly distributed throughout the universe and the whole universe is needed to study it. There are two basic methods to explore the properties of Dark Energy, viz. geometrical tests (supernovae) and studies of the way in which Dark Energy has influenced the large scale structure of the universe and its evolution. DUO will use the latter method, employing the copious X-ray emission from clusters of galaxies. Clusters of galaxies offer an ideal probe of cosmology because they are the best tracers of Dark Matter and their distribution on very large scales is dominated by the Dark Energy. In order to take the next step in understanding Dark Energy, viz. the measurement of the 'equation of state' parameter 'w', an X-ray telescope following the design of ABRIXAS will be accommodated into a Small Explorer mission in lowearth orbit. The telescope will perform a scan of 6,000 sq. degs. in the area of sky covered by the Sloan Digital Sky Survey (North), together with a deeper, smaller survey in the Southern hemisphere. DUO will detect 10.000 clusters of galaxies, measure the number density of clusters as a function of cosmic time, and the power spectrum of density fluctuations out to a redshift exceeding one. When combined with the spectrum of density fluctuations in the Cosmic Microwave Background from a redshift of 1100, this will provide a powerful lever arm for the crucial measurement of cosmological parameters.
The XMM-Newton observatory, with its high throughput in combination with the EPIC CCD-cameras, is an ideal instrument to study extended sources like clusters of galaxies. Very deep observations of galaxy clusters reveal substructure on different levels: structure associated with bright galaxies, faint galaxies, or structure consistent with the merger of groups with the main cluster. Another indication of substructure is the deviation of the temperature of the intra-cluster gas from isothermality. We present XMM-Newton mosaic observations of the nearby clusters A3667 and A754. These clusters are good representatives of the different evolution stages that all clusters experience as they grow from mergers of smaller groups. Hence they show merging at different phases, which is also reflected in the different appearance of their temperature maps, pressure maps and entropy maps.
We report on the current status of the background calibration of the EPIC pn-CCD camera on board XMM-Newton. The intrinsic background is comprised of internal electronic noise, and continuous and fluorescent X-ray emission induced by high-energy particles. Soft protons passing through the X-ray telescope (and finally also true cosmic X-rays) contribute to the registered events. The camera background has been monitored by using data in closed filter positions for three years; we review the spectral, spatial, and temporal distribution, for all commissioned instrument modes.
This paper also discusses briefly the effects on scientific data analysis and conclusions for further observations and detectors.
The X-ray Observatory XMM-Newton is in orbit since December 1999. We will report on the current status of the in-flight spectral calibration of the EPIC-pn camera. Using the internal calibration source and line spectra of supernova remnants the calibration of the energy scale has been monitored over the first years of operations. Continuum spectra of celestial objects like Active Galactic Nuclei or isolated neutron stars were used for cross-calibrating the instruments. We report on recent improvements in the spectral calibration as well as still existing problems.
The X-ray Observatory XMM-Newton is in orbit since the 10<sup>th</sup> December 1999. In the first half year an extensive program to commission, calibrate and verify the performance of the payload has been carried out. Since then many routine calibrations, using the onboard calibration source as well as many different celestial objects, have been performed. In this paper we will report on the status of the calibration of the EPIC-pn camera in general and focus on major points like the CTI evolution, the effective area, the response function and the instrumental background.
SIMBOL-X is a hard X-ray mission, operating in the 0.5-70 keV range, which is proposed by a consortium of European laboratories for a launch around 2010. Relying on two spacecraft in a formation flying configuration, SIMBOL-X uses a 30 m focal length X-ray mirror to achieve an unprecedented angular resolution (30 arcsec HEW) and sensitivity (100 times better than INTEGRAL below 50 keV) in the hard X-ray range. SIMBOL-X will allow to elucidate fundamental questions in high energy astrophysics, such as the physics of accretion onto Black Holes, of acceleration in quasar jets and in supernovae remnants, or the nature of the hard X-ray diffuse emission. The scientific objectives and the baseline concepts of the mission and hardware design are presented.
The main scientific objective of the ROSITA mission is to extend the X-ray all-sky survey of ROSAT to higher energies to gain an unbiased sample of all types of celestial X-ray sources in the medium energy band. During this mission the whole sky will be scanned by seven imaging X-ray telescopes. The telescopes have different viewing directions with an offset angle between 4 and 6 deg. The focal plane instrumentation of the telescopes is based on a novel type of pn-CCD with a frame store, an advanced version of the pn-CC operating quite successfully on XMM-Newton. The pixel size is adapted to the
mirror resolution and the fast readout time guaranties the required angular accuracy despite the scan motion. The X-ray camera carries seven separate CCDs arranged on a circle in the foci of the Wolter type I mirror systems of the seven telescopes. The CCDs are mounted on ceramic frames, which carry dedicated front-end electronics for each CCD. The CCDs are operated at a temperature of-80 deg C. Except for the entrance window, the CCDs are covered by graded shielding for suppression of fluorescent X-ray background, generated by cosmic rays in the surrounding materials. Filters in front of the the CCDs, inhibit optical and UV photons. For in-orbit calibration a radioactive
source producing fluorescent X-rays in the desired energy band is provided. We will give an overview of the mechanical, thermal and electrical concept of the camera system.
EPIC, on the Newton Observatory, comprises three CCD cameras that provide spectroscopic imaging over the band 0.1-12 keV, with full coverage of the 30' diameter field of view of the three telescopes. The combination of bandwidth, throughput, and spectral resolution, has produced many interesting observations in more than two years of operation. These range from stars, normal, and neutron, SNR & Pulsars, via galaxies, to clusters of galaxies and the most distant quasars. Some of the latest results will be presented. A few days' operation on orbit provides more instrument performance data that can be gathered in the most thorough ground calibration, and many new facets of the instrument performance become evident in orbit. The high throughput of the Newton telescopes provides images and spectra of high statistical precision. This puts an additional burden on the calibration, and there has been much progress by the EPIC team in defining a precise and accurate calibration at the few percent level. The EPIC MOS CCDs perform well in orbit and show considerable radiation hardness against soft protons, due to their peculiar architecture. The degradation of spectral resolution, due to radiation damage, is dominated by hard solar flare protons. At present, this is within the predicted limits and the good spectral performance of EPIC is maintained.
The x-ray observatory XMM-Newton is in orbit since the 10 December 1999. In the first half-year an extensive program has been carried out to commission, calibrate and verify the performance of the payload, followed by the routine phase, in which guaranteed time observations and regular guest observer programs are conducted. After a short discussion of the pn-CCD camera and its in-orbit calibration, I will present scientific results, concentrating on observations of super nova remnants, galaxies and clusters of galaxies. They demonstrate the excellent peformance of the pn-camera.
The combined effective area of the three EPIC cameras of the XMM-Newton Observatory, offers the greatest collecting power ever deployed in an X-ray imaging system. The resulting potential for high sensitivity, broad-band spectroscopic investigations demands an accurate calibration. This work summarizes the initial in-orbit calibration activities that address these requirements. We highlight the first steps towards effective area determination, which includes the maintenance of gain CTI calibration to allow accurate energy determination. We discuss observations concerning the timing and count-rate capabilities of the detectors. Finally we note some performance implications of the optical blocking filters.
XMM-Newton, the most powerful X-ray telescope ever built was launched from the european space port Kourou on december 10 last year. Three large X-ray Wolter type mirror systems are focusing the incoming X-rays from 100 eV up to 15,000 eV onto the focal instruments: fully depleted backside illuminated pn-CCDs and frontside illuminated MOS-CCDs. The concept of the pn-CCD camera will be briefly described and its performance on ground and in orbit will be shown. Special emphasis will be given to the radiation hardening of the devices, to the instrument background and to the experience of charged particle background in space. A comparison of the performance on ground and after 5 months in space will be shown.
The in-orbit imaging performance of the three X-ray telescopes on board of the X-ray astronomy observatory XMM- Newton is presented and compared with the performance measured on ground at the MPE PANTER test facility. The comparison shows an excellent agreement the on ground and in-orbit performance.
On 10th December 1999, the European X-ray satellite XMM, now called XMM-Newton, was successfully put into orbit. After initial commissioning of the satellite's subsystems, the EPIC-pn camera was switched on and tested thoroughly in the period Jan./Febr. 2000. After refining of some of the parameter settings and the on-board pn-computer programs, we started the Calibration and Performance Verification Phase, which will last until the end of May 2000. In this paper we report on the results of the EPIC-pn Commissioning Phase with respect to the in-orbit performance of the camera. We also show some of the early results with the pn-camera, the first light image of a region in the Large Magellanic Cloud, and an observation of the Crab Nebular.
The pn-Charge Coupled Device (pn-CCD) camera was developed as one of the focal plane instruments for the European Photon Imaging Camera on board the x-ray multi mirror mission. An identical camera was foreseen on board ABRIXAS, a German x-ray satellite. The pn-CCD camera is an imaging x- ray detector for single photon counting, operating at a temperature below -80 degrees C. Due to a 0.3 mm depletion depth of the CCDs, the detector has a high quantum efficiency up to 15 keV. The effective area of the instrument is 6 cm X 6 cm with 12 CCDs monolithically integrated on a single silicon wafer. The camera includes a filter wheel with different filters for suppression of optical and UV light. A radioactive source provides an in- orbit calibration. In this paper we give an overview of the mechanical, thermal and electrical design of the instrument and a description of different readout and test modes. More detailed information about the performance and calibration of the instrument can be found in companion papers.
The pn-EPIC system flight module of XMM was calibrated using the IAS synchrotron facility at Orsay, France. Based on this measurements, a model for the energy response of the pn-CCD was fitted to the data. Only one of the fitted parameters shows significant spatial dependence, while the others only depend on energy. Based on the interpolated parameters, the detector response matrix has been calculated using the partial event model. The validity of this matrix has been tested on existing calibration data. The detector response matrix will be used to analyze spectral observation data taken with pn-EPIC on XMM.
In the near future the European x-ray satellite XMM will be launched into orbit. The satellite is equipped with a PN-CCD camera with a sensitive area of 60 mm X 60 mm, integrated on a single silicon wafer. The same camera is on board of the German x-ray satellite ABRIXAS. The main feature of this camera type is the very good quantum efficiency of more than 90 percent in the energy range from 0.3 to 10 keV and the high time resolution, selectable between 7 microsecond(s) ec and 280 msec. All flight cameras are extensively calibrated, utilizing the long beam test facility Panter in Muenchen, the Synchrotron Radiation Facility beam lines at the Institut d'Astrophysique Spatiale in Orsay, and the PTB beam line at the Bessy Synchrotron in Berlin. We will give an overview of all the calibrations and calibration methods as well as some global results.
A single-photon counting x-ray camera based on a fully depleted pn-CCD was developed by the Max-Planck-Institut fuer extraterrestrische Physik. It will be used on the european x-ray satellite XMM as one out of three focal plane detectors. The radiation hard device exhibits an intrinsic charge transfer loss due to titanium deep level trap contamination in the starting material. In order to realize the high spectral resolution of the device, the effects of charge transfer loss have to be corrected. The loss is a function of temperature, signal charge, clocking and the individual transfer history of a transfer channel. A model based on the capture and emission process of electron is in deep level traps has been developed and is applied to the charge transfer loss of the MPE pn-CCD x-ray camera. Each signal is corrected individually. The electron distribution within the potential well and the timing scheme is taken into account. The effect of charge generation due to thermally generated current and residual light proves to be an important parameter of the model. The model is in god agreement with the calibration data of the camera.
The quantum efficiency of the pn-CCD detector on the XMM satellite mission was determined in the spectral range between 150 eV and 15 keV. The unstructured entrance window of the device, which is formed by an ultrathin reverse biased pn-junction, results in an excellent spatial homogeneity with a good spectroscopic performance and high detection efficiency for low energy photons. The large sensitive thickness of the detector guarantees a high quantum efficiency for photons up to 10 keV. We give a review of the calibration techniques applied for quantum efficiency measurements at the Synchrotron Radiation Facility at the Institut d'Astrophysique Spatial in Orsay and the radiometry laboratory of the Physikalisch-Technische Bundesandstalt at the electron storage ring BESSY in Berlin. We summarize the applied data correction such as charge transfer loss and split event recognition and describe the data analysis to conclude in an absolute quantum efficiency of the pn-CCD.
In CCDs part of the charge released by an absorbed photon is lost during transfer to the readout node. This loss depends on several parameters, in particular on the position where the photon was detected, its energy, the temperature of the CCD, and the saturation of traps by charges preceding along the readout direction. In order to determine how these parameters affect the charge loss of the pn-CCD cameras, we obtained extensive sets of calibration measurements form February 1998 to January 1999. More than three billion events were recorded in flatfield exposures. We present results of a detailed analysis of this data set and describe how they can be used to correct pn-CCD camera data for charge transfer loss.
The XMM, the second corner stone mission of the European Space Agency's Horizon 2000, will be launched in December 1999. One of the instruments on board of XMM will be the EPIC pn-CCD. The detector consists of four independent quadrants integrated monolithically on a single silicon wafer. Each quadrant is divided into 3 CCDs with 200 X 64 pixels and 280 micrometers depletion depth. The pn-CCD will be able to perform high resolution timing analysis as well as high throughput imaging and spectroscopy in six different readout modes. In the standard imagin mode the CCDs are read out sequentially every 73.3 ms. In addition, different readout modes allow high resolution timing analysis by reducing the integration time down to 7 microsecond(s) and reading out only one CCD. In this paper we show results of the calibration of the flight spare unit of the EPIC pn camera with respect to time resolution of all observation modes. In the first part we explain the detailed timing of each mode and show how one can calculate the best possible arrival time for photons in each observation mode. In the second part of the paper, we analyzed the influence of the readout noise on the time resolution of the pn-CCD camera, by combining dead time functions with simulated light curves.
A 6 cm X 6 cm large monolithic charge coupled device has been developed and fabricated as focal plane x-ray detector for the European XMM satellite mission and the German ABRIXAS mission. This spectroscopic silicon detector is denominated pn-CCD because of its use of reverse biased pn- junctions as charge transfer registers, as ultra-thin homogeneous photon entrance window and for the on-chip electronics. Due tot he pn-CCD concept, the whole wafer thickness of 300 micrometers is sensitive to ionizing radiation. The read-out is performed in parallel and needs only 73 ms for the 36 cm<SUP>2</SUP> large detector area. A uniform low noise performance is realized by on-chip integrated JFET electronics. The two best pn-CCDs have been integrated in the flight cameras for XMM and abrixas and extensively tested for the long term operation in space. The presentation comprises the basic concept of the detector, a short description of the flight device and its fabrication, test and operating as well as the key performance parameters. The concluding outlook describes methods of further development of the pn-CCD.
The pm-CCD camera is one of the three focal plane instruments of the European Photon Imaging Camera (EPIC) on board the x-ray multi mirror (XMM) mission scheduled for launch in August 1999. The detector consists of four quadrants of three pn-CCDs each, which are integrate don one 4 inch silicon wafer. Each CCD has 200 by 64 pixels with 280 micrometers depletion depth. One CCD of a quadrant is readout at a time, while the four quadrants can be processed independently of each other. Observations of point sources brighter than 11 mCrab in imaging mode will be effected by photon pile-up. However, special operating modes can be used to observe bright sources up to 150 mCrab in Timing Mode with 30 microsecond(s) time resolution and very bright sources up to several Crab in Burst Mode with 7 microsecond(s) time resolution. We have tested and calibrate the flight model FM of the EPIC pn-CCD camera at the long beam test facility Panter near Munich and at the synchrotron monochromators of the Institut d'Astrophysique Spatiale in Orsay, France. In this paper describe the calibration of the pn-CCD detector in high time resolution/bright source operating modes and present preliminary results on the performance in these modes.
The x-ray multi mirror (XMM) mission, the second cornerstone of the European Space Agency's Horizon 2000 program, will be launched in August 1999 and will perform high throughput imaging and spectroscopy in the energy range form 0.1 to 15 keV. One of the focal plane instruments is the EPIC pn CCD camera with a sensitive area of 60 mm by 60 mm, integrated on a single silicon wafer. The camera is divided into 4 redundant quadrants of three 10 mm by 30 mm CCDs with 64 by 200 pixels each. The thin entrance window in combination with a depletion depth out modes give the flexibility to observe targets of different source strength up to several Grab with some reduction in spectral and spatial performance. We will report on the calibration of the flight unit of the EPIC pm camera, performed at the long beam test facility Panter in Muenchen and at the Synchrotron Radiation Facility beam lines at the Istitute d'Astrophysique Spatiale in Orsay. In this paper we describe the preliminary results of the calibration of the imaging modes.
The pn-CCD camera is developed as one of the focal plane instruments for the European photon imaging camera (EPIC) on board the x-ray multi mirror (XMM) mission to be launched in 1999. The detector consists of four quadrants of three pn-CCDs each, which are integrated on one silicon wafer. Each CCD has 200 by 64 pixels (150 micrometer by 150 micrometers) with 280 micrometers depletion depth. One CCD of a quadrant is read out at a time, while the four quadrants can be processed independently of each other. In standard imaging mode the CCDs are read out sequentially every 70 ms. Observations of point sources brighter than 1 mCrab will be effected by photon pile- up. However, special operating modes can be used to observe bright sources up to 150 mCrab in timing mode with 30 microseconds time resolution and very bright sources up to several crab in burst mode with 7 microseconds time resolution. We have tested one quadrant of the EPIC pn-CCD camera at line energies from 0.52 keV to 17.4 keV at the long beam test facility Panter in the focus of the qualification mirror module for XMM. In order to test the time resolution of the system, a mechanical chopper was used to periodically modulate the beam intensity. Pulse periods down to 0.7 ms were generated. This paper describes the performance of the pn-CCD detector in timing and burst readout modes with special emphasis on energy and time resolution.
Monolithic arrays of 12 CCDs, 3 by 1 cm<SUP>2</SUP> each, have been developed and produced for the focal plane instrumentation of the European photon imaging camera (EPIC) on XMM and the German ABRIXAS x-ray satellite mission. The design parameters have been optimized to match the properties of the x-ray imaging optics as well as the x-ray intensity, energy bandwidth and characteristic time constants of the objects to observe. The pixel size is 150 by 150 micrometer<SUP>2</SUP>; readout is performed in parallel; low noise, spectroscopic performance is realized by on-chip integrated JFET electronics; highohmic, ultrapure bulk material allows full depletion and enhances the efficiency for higher energy x-ray detection. The fabrication process, the layout topology and the operating conditions guarantee for a ten year operation in space without performance degradation.
The pn-charge coupled device (pn-CCD) camera was developed as one of the focal plane instruments for the European photon imaging camera (EPIC) on board the x-ray multi mirror (XMM) mission. The homogeneously sensitive detector consists of four quadrants of three pn-CCDs each, which are integrated on a single silicon wafer. Each CCD has an area of 10 mm by 30 mm divided into 64 by 200 pixels with a depletion depth of 280 micrometers. Altogether the sensitive area is 60 mm by 60 mm. In the standard imaging mode (full frame mode) the CCDs are read out sequentially every 70 ms. In addition, different window modes allow imaging of brighter sources by restricting the detector area and reducing the integration time down to 6 ms. We have tested one quadrant of the EPIC pn-CCD camera at line energies from 0.52 keV to 17.4 keV at the long beam test facility PANTER in focus of the qualification mirror module for XMM as well as in a homogeneous x-ray beam. In this paper we describe the tests in the different imaging modes and report on the performance.
The prime focal instrument of the x-ray astronomy satellite ROSAT is the position sensitive proportional counter (PSPC). It is a conventional multiwire gas counter for the energy range from 0.1 to 2.4 keV. At a photon energy of 1 keV the PSPC has an energy resolution of 41% (FWHM), a position resolution of 230 micrometer and a quantum efficiency of 50%. With its very high charged particle background rejection efficiency of better than 99% the detector is best suited for deep exposures to reach so far unprecedented low x-ray flux limits, and also for imaging of extended low surface brightness objects. We describe the detector, report on its in- orbit performance, and present some highlights of the ROSAT all-sky survey and from pointed PSPC observations.