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A. Merloni,
P. Predehl,
W. Becker,
H. Böhringer,
T. Boller,
H. Brunner,
M. Brusa,
K. Dennerl,
M. Freyberg,
P. Friedrich, [......],
K. Nandra,
A. Rau,
T. H. Reiprich,
J. Robrade,
M. Salvato,
A. Santangelo,
M. Sasaki,
A. Schwope,
J. Wilms,
the German eROSITA Consortium
[show abstract]
[hide abstract]
ABSTRACT: eROSITA is the primary instrument on the Russian SRG mission. In the first
four years of scientific operation after its launch, foreseen for 2014, it will
perform a deep survey of the entire X-ray sky. In the soft X-ray band (0.5-2
keV), this will be about 20 times more sensitive than the ROSAT all sky survey,
while in the hard band (2-10 keV) it will provide the first ever true imaging
survey of the sky at those energies. Such a sensitive all-sky survey will
revolutionize our view of the high-energy sky, and calls for major efforts in
synergic, multi-wavelength wide area surveys in order to fully exploit the
scientific potential of the X-ray data. The design-driving science of eROSITA
is the detection of very large samples (~10^5 objects) of galaxy clusters out
to redshifts z>1, in order to study the large scale structure in the Universe,
test and characterize cosmological models including Dark Energy. eROSITA is
also expected to yield a sample of around 3 millions Active Galactic Nuclei,
including both obscured and un-obscured objects, providing a unique view of the
evolution of supermassive black holes within the emerging cosmic structure. The
survey will also provide new insights into a wide range of astrophysical
phenomena, including accreting binaries, active stars and diffuse emission
within the Galaxy, as well as solar system bodies that emit X-rays via the
charge exchange process. Finally, such a deep imaging survey at high spectral
resolution, with its scanning strategy sensitive to a range of variability
timescales from tens of seconds to years, will undoubtedly open up a vast
discovery space for the study of rare, unpredicted, or unpredictable
high-energy astrophysical phenomena. In this living document we present a
comprehensive description of the main scientific goals of the mission, with
strong emphasis on the early survey phases.
09/2012;
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E. Perinati,
S. Diebold,
E. Kendziorra,
A. Santangelo,
C. Tenzer,
J. Jochum,
S. Bugiel,
R. Srama,
E. Del Monte,
M. Feroci, [......],
C. A. Kilbourne, N. Meidinger,
L. Strüder,
B. Cordier,
D. Götz,
G. W. Fraser,
J. P. Osborne,
K. Dennerl,
M. Freyberg,
P. Friedrich
[show abstract]
[hide abstract]
ABSTRACT: We report on our activities, currently in progress, aimed at performing
accelerator experiments with soft protons and hyper-velocity dust particles.
They include tests of different types of X-ray detectors and related components
(such as filters) and measurements of scattering of soft protons and
hyper-velocity dust particles off X-ray mirror shells. These activities have
been identified as a goal in the context of a number of ongoing space projects
in order to assess the risk posed by environmental radiation and dust and
qualify the adopted instrumentation with respect to possible damage or
performance degradation. In this paper we focus on tests for the Silicon Drift
Detectors (SDDs) used aboard the LOFT space mission. We use the Van de Graaff
accelerators at the University of T\"ubingen and at the Max Planck Institute
for Nuclear Physics (MPIK) in Heidelberg, for soft proton and hyper-velocity
dust tests respectively. We present the experimental set-up adopted to perform
the tests, status of the activities and some very preliminary results achieved
at present time.
09/2012;
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N. Meidinger,
R. Andritschke,
W. Assmann,
S. Ebermayer,
J. Elbs,
O. Halker,
E. Heindl,
S. Herrmann,
N. Kimmel,
D. Pietschner,
J. Reiffers,
S. Reinhardt,
G. Schachner,
L. Struder,
G. Weidenspointner
[show abstract]
[hide abstract]
ABSTRACT: The German X-ray telescope eROSITA is the core instrument on the Russian satellite Spectrum-Roentgen-Gamma (SRG). Its scientific goal is the exploration of the X-ray Universe in the energy band from about 0.3 keV up to 10 keV with excellent energy, time and spatial resolution and large effective telescope area. The launch of the SRG satellite is scheduled for 2013. The observational program divides the planned mission duration of seven years into an all-sky survey and pointed observations. For detection of the single X-ray photons with high resolution, adequate frame transfer pnCCDs and the associated front-end electronics have been developed. The back-illuminated, 450 μm thick and fully depleted pnCCDs with a 3 cm × 3 cm large image area have been produced in the MPI Halbleiterlabor in the course of further development of the XMM-Newton X-ray pnCCDs. By means of the concept of back-illumination and full depletion of the chip thickness, high quantum efficiency is obtained over the entire energy band of interest. The performance of each eROSITA CCD was tested on chip level using a so-called `cold chuck probe station'. A special feature of this setup is that it allows spectroscopic measurements with a <sup>55</sup>Fe source. Based on these results, we will select the seven best CCDs for the eROSITA focal plane cameras. An analog signal processor with 128 parallel channels has been developed for readout of the pnCCD signals. This ASIC permits fast and low-noise signal filtering. For a detailed characterization of the CCD detectors an appropriate control, supply and data acquisition electronics system was developed. We achieve a read noise of 2 electrons rms and an energy resolution of 135 eV FWHM for photons with energy of 5.9 keV. Even at the low X-ray energy of 280 eV, we measure a spectrum of Gaussian shape with a FWHM of 52 eV. However, the energy resolution will degrade during the seven years in space due to radiation damage caused by protons. The-
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radiation damage effect was studied and quantified for the eROSITA CCDs in an experiment. After successful development and verification of the CCD and its signal processor chip, we have started to assemble a flight-like eROSITA camera.
Nuclear Science Symposium Conference Record (NSS/MIC), 2010 IEEE; 12/2010
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R. Andritschke, N. Meidinger,
J. Elbs,
R. Hartmann,
A. Ziegler,
N. Kimmel,
G. Schachner,
S. Ebermayer,
S. Herrmann,
O. Halker,
J. Reiffers,
P. Holl,
F. Schopper,
L. Struder,
H. Soltau,
W. Assmann,
S. Reinhardt
[show abstract]
[hide abstract]
ABSTRACT: A PNCCD is successfully operating as one of the focal plane CCDs aboard the satellite XMM-Newton. An advanced version of this kind of CCDs will be the sensing devices for the eROSITA X-ray astronomy mission. These fully depleted CCDs are developed and manufactured at the MaxPlanck-Institute Semiconductor Lab together with the company PNSensor. Their performance features make them useful in a variety of measurement situations in addition to the astronomical ones. Applications range from photon detection (e.g. optical wave front sensors, cameras for X-ray free electron lasers) to charged particle detection of e.g. electrons, protons, and alpha particles. First tests have been performed for using a PNCCD in a transmission electron microscope (TEM). Alpha particles of an <sup>241</sup>Am radioactive source are used for generating large signal electron clouds for diagnostic purposes. Finally, protons have been used in a radiation hardness test. These three applications will be described and discussed. The prospect of resolving space and energy of each particle in combination with ~100% efficiency makes the PNCCD especially suitable for low flux applications e.g. examining sensitive samples in a TEM.
Nuclear Science Symposium Conference Record (NSS/MIC), 2010 IEEE; 12/2010
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N. Cappelluti,
P. Predehl,
H. Boehringer,
H Brunner,
M. Brusa,
V. Burwitz,
Evgeniy Churazov,
K. Dennerl,
M. Freyberg,
A. Finoguenov, [......],
M. Muehlegger,
M. Pavlinsky,
J. Robrade,
A. Santangelo,
J Schmitt,
A. Schwope,
M. Steinmitz,
L. Strueder,
R. Sunyaev,
C. Tenzer
[show abstract]
[hide abstract]
ABSTRACT: eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is the core instrument on the Russian Spektrum-Roentgen-Gamma (SRG) mission which is scheduled for launch in late 2012. eROSITA is fully approved and funded by the German Space Agency DLR and the Max-Planck-Society. The design driving science is the detection of 50 - 100 thousands Clusters of Galaxies up to redshift z ~ 1.3 in order to study the large scale structure in the Universe and test cosmological models, especially Dark Energy. This will be accomplished by an all-sky survey lasting for four years plus a phase of pointed observations. eROSITA consists of seven Wolter-I telescope modules, each equipped with 54 Wolter-I shells having an outer diameter of 360 mm. This would provide and effective area at 1.5 keV of ~ 1500 cm2 and an on axis PSF HEW of 15" which would provide an effective angular resolution of 25"-30". In the focus of each mirror module, a fast frame-store pn-CCD will provide a field of view of 1 deg in diameter for an active FOV of ~ 0.83 deg^2. At the time of writing the instrument development is currently in phase C/D. Comment: 5 pages 3 figures, Proceedings of the WFXT meeting, to appear on "Memorie della Societa' Astronomica Italiana"
04/2010;
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[show abstract]
[hide abstract]
ABSTRACT: Since several years, charge coupled devices (CCD) type detectors are used in X-ray satellite missions in the focus of imaging
optics (e.g., ASCA, Chandra, XMM-Newton, Swift, Suzaku). They measure position, energy, and arrival time of individual X-rays
from 100eV to 15 keV energy. The Japanese ASCA satellite was the first X-ray mission to employ CCDs as a focal plane detector
in 1993. The US American Chandra and the European XMM-Newton missions followed with larger detector arrays and improved performance
in 1999.
12/2007: pages 51-71;
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[show abstract]
[hide abstract]
ABSTRACT: Imaging detectors with high quantum efficiency over a wide spectral range, low noise, and fast readout will prove to be very
useful in many applications in astronomy and other fields. In 2005 we have started to develop pnCCDs with high quantum efficiency
for fast imaging of single optical photons in the wavelength range ∽350–1100 nm. The concept is based on fully depleted, back-illuminated
pnCCDs with a sensitive thickness of 450 μmum which were originally developed for fast single photon X-ray imaging and spectroscopy.
The pnCCD with column parallel readout shall be modified such that the on-chip JFET amplifiers are replaced by avalanche amplifier
(AA) cells operated in the linear regime with a gain up to a few thousand. An additional on-chip n-channel MOSFET manages
the suitable change of impedance such that the resulting signal can be handled by the following CAMEX readout ASICs. The amplification
of the avalanche process must be sufficiently low to prevent optical crosstalk between the detector channels. The anticipated
format in the imaging area will be of the order of 256× 256 pixels with a size of ∽50 μmum. The frame rate should be as high
as 1000 frames per second.
10/2007: pages 281-289;
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P. Predehl,
R. Andritschke,
W. Bornemann,
H. Bräuninger,
U. Briel,
H. Brunner,
W. Burkert,
K. Dennerl,
J. Eder,
M. Freyberg, [......],
J. Wilms,
M. Erhard,
S. Gutruf,
D. Jugler,
D. Kampf,
R. Graue,
O. Citterio,
G. Valsecci,
D. Vernani,
M. Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: 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.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
09/2007;
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P. Holl,
R. Andritschke,
R. Eckhardt,
R. Hartmann,
C. Koitsch,
G. Lutz, N. Meidinger,
R.H. Richter,
G. Schaller,
H. Soltau,
L. Struder,
G. Valceanu
[show abstract]
[hide abstract]
ABSTRACT: We report on first measurements from test structures verifying a new design concept of a single photon imaging CCD for the optical. The results confirm the sensitivity of a novel avalanche diode to single electrons. Details of this structure which can be combined with a back illuminated sensor are described, measurement results include I-V curves, dark rate and temperature dependency. In addition an avalanche diode with MOSFET readout will be presented as well as an ultra low noise pnCCD which is process compatible. The successful testing of these components proves the feasibility to produce a back-illuminated single photon sensitive CCD with high frame rates and high sensitivity in a wide wavelength range.
Nuclear Science Symposium Conference Record, 2006. IEEE; 12/2006
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E. Pfeffermann,
A. Deresch,
P. Friedrich,
R. Hartmann,
G. Hartner,
G. Hasinger,
S. Herrmann,
H. Hippmann,
E. Kendziorra,
G. Kettenring,
W. Kink, N. Meidinger,
S. Muller,
P. Predehl,
C. Rohe,
L. Struder
[show abstract]
[hide abstract]
ABSTRACT: The X-ray astronomy satellite ROSITA is planned to perform an X-ray all sky survey in the medium energy range up to 10 keV with an imaging telescope. During the mission the whole sky will be scanned and selected areas will be observed with longer exposures. Especially cosmic X-ray sources obscured by large amounts of gas and dust like accreting black holes and active galactic nuclei as well as the hot gas of distant clusters of galaxies can be seen in this energy band. The ROSITA payload consists of an imaging X-ray telescope made of seven separate mirror modules with different viewing directions. Each module has a 27 fold nested Wolter type I mirror system. The seven mirror systems share a common X-ray camera in the focal plane with seven single frame store pnCCD detectors, each dedicated to one mirror module. The frame store pnCCD is a further development of the pnCCD detector of the EPIC camera aboard the XMM-Newton satellite. Due to the high readout frequency of the CCDs (20 s<sup>-1</sup>) the angular resolution of the telescope is not degraded despite the scanning motion of the satellite. The CCDs are operated at a temperature of -80°C. Cooling is provided by passive radiators and thermoelectric coolers. To reduce the fluorescent X-ray background, generated by cosmic radiation in the materials of the detector housing, the CCDs are surrounded by a graded shielding. The detector performance will be checked in orbit with calibration sources. We will give an overview of the mechanical, thermal and electrical concept of the focal plane camera system.
Nuclear Science Symposium Conference Record, 2005 IEEE; 11/2005
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K. Dennerl,
B. Aschenbach,
U. G. Briel,
H. Brunner,
V. Burwitz,
J. Englhauser,
M. J. Freyberg,
F. Haberl,
G. Hartner,
A. F. Iyudin,
E.. Kendziorra, N. Meidinger,
E. Pfefferman,
W. Pietsch,
L. Strüder,
V. E. Zavlin
05/2005; -1:153-158.
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H Bräuninger,
H Böttcher,
W Burkert,
D Carathanassis,
N Findeis,
G Hagl,
G Hartner,
D Hauff,
M Hengmith,
H Hippmann, [......],
R Richter,
J Schaumberger,
G Schwaab,
H Seitz,
R Sigl,
H Soltau,
R Staubert,
L Strüder,
J Trümper,
C von Zanthier
[show abstract]
[hide abstract]
ABSTRACT: The X-ray Multi Mirror (XMM) satellite mission is one of the major European Space Agency (ESA) space missions scheduled for launch by the end of this decade. Its goal is to observe the x-ray-emitting sky in the 100 eV to 15 keV photon energy range with high spectral and spatial resolution. XMM's scientific instruments consist mainly of three independent Wolter telescopes each having an imaging charge-coupled-device (CCD) detector in the focal plane. Two of the three telescopes are equipped with CCDs based on the conventional MOS-CCD technology. The third is equipped with pn-CCDs, a new developement of the semiconductor laboratory of the Max-Planck-Institut fur extraterrestrische Physik. The pn-CCD has several features such as full detector depletion, parallel readout and good radiation hardness due to the replacement of the MOS structures with pn-diode electrodes. The design of the pn-CCD detector for XMM is shown and measurements with pn-CCD prototype units are presented.
Metrologia 04/2003; 32(6):643. · 1.75 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: The pn camera of EPIC is inherently robust against radiation damage effects. Nevertheless, the knowledge of charge transfer inefficiency (CTI) of the pn camera is crucial for obtaining the correct energy scale. We describe detailed in-orbit monitoring of this effect, utilizing the internal calibration source. We find that during the first two years in orbit the CTI increased by about 4% for Al-K and by about 7% for Mn-K. The increases in the CTI are well within expectations, with no measurable effect on the energy resolution.
05/2002;
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Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series; 12/2000
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K. Dennerl,
F. Haberl,
B. Aschenbach,
U. G. Briel,
M. Balasini,
H. Braeuninger,
W. Burkert,
R. Hartmann,
G. Hartner,
G. Hasinger, [......],
E. Pfeffermann,
W. Pietsch,
C. Reppin,
H. Soltau,
R. Staubert,
L. Strueder,
J. Truemper,
M Turner,
G Villa,
V. E. Zavlin
[show abstract]
[hide abstract]
ABSTRACT: We present the XMM-Newton first light image, taken in January 2000 with the EPIC pn camera during the instrument's commissioning phase, when XMM-Newton was pointing towards the Large Magellanic Cloud (LMC). The field is rich in different kinds of X-ray sources: point sources, supernova remnants (SNRs) and diffuse X-ray emission from LMC interstellar gas. The observations are of unprecedented sensitivity, reaching a few 10^32 erg/s for point sources in the LMC. We describe how these data sets were analysed and discuss some of the spectroscopic results. For the SNR N157B the power law spectrum is clearly steeper than previously determined from ROSAT and ASCA data. The existence of a significant thermal component is evident and suggests that N157B is not a Crab-like but a composite SNR. Most puzzling is the spectrum of the LMC hot interstellar medium, which indicates a significant overabundance of Ne and Mg of a few times solar. Comment: to be published in A&A 365
11/2000;
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U ~G Briel,
B Aschenbach,
M Balasini,
H ~W Braeuninger,
W Burkert,
K Dennerl,
M Ehle,
F Haberl,
R Hartmann,
G ~D Hartner, [......],
M Popp,
A Read,
C Reppin,
H Soltau,
R Staubert,
L Strueder,
J ~E Truemper,
G ~E Villa,
C Zanthier,
V ~E Zavlin
Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series; 07/2000
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U ~G Briel,
E Bihler,
H ~W Braeuninger,
M Colli,
K Dennerl,
F Haberl,
R Hartmann,
G ~D Hartner,
P Holl, N Meidinger,
J Kemmer,
E Kendziorra,
M Kirsch,
N Krause,
M Kuster
Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series; 10/1999
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[show abstract]
[hide abstract]
ABSTRACT: The development of a novel charge coupled device, the fully
depleted pn-junction CCD (pn-CCD), has been completed. It will be used
as focal plane detector for X-ray imaging and spectroscopy on two
scientific satellite missions, XMM and ABRIXAS. A comprehensive,
quantitative study of the radiation damage in the pn-CCD was performed
with 10-MeV protons, 5.5 MeV alpha-particles and soft X-rays. The
irradiation by soft X-rays with a dose of 23 krad(Si) caused no
performance degradation. The A-centre (oxygen-vacancy defect) and the
divacancy trap were generated by particle irradiations which are both
inevitably in silicon. But no other trap type affected the charge
transfer in the tested operating temperature range between 75 K and 240
K. The formation probability of the dominant trap type, the A-centre, is
presented for proton and alpha-particle irradiation. We have measured
the effects of particle fluence and temperature on trap generation as
well as the variation of trap concentration. The measured energy
resolution of the irradiated pn-CCDs proves the high radiation hardness
of this type of charge coupled device. The full width at half maximum of
the Mn-K<sub>α</sub> line (5894 eV) was increased from 135 eV to
175 eV (FWHM/E=3%) after exposure to a 10-MeV proton fluence of
2.10<sup>9</sup> cm<sup>-2</sup>. The results differ from that of other
charge coupled devices because of the different detector concept and
fabrication process
IEEE Transactions on Nuclear Science 01/1999; · 1.45 Impact Factor
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U ~G Briel,
H ~W Braeuninger,
K Dennerl,
C Greiveldinger,
F Haberl,
G ~D Hartner, N Meidinger,
N Krause,
M Popp,
E Pfeffermann, [......],
E Bihler,
W Grubmiller,
E Kendziorra,
M Kirsch,
M Kuster,
B Pflueger,
P Holl,
J Kemmer,
H Soltau,
C Zanthier
Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series; 11/1998
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E Kendziorra,
E Bihler,
M Colli,
M Kirsch,
M Kuster,
B Pflueger,
R Staubert,
H ~W Braeuninger,
U ~G Briel,
K Dennerl, [......],
G ~D Hartner, N Meidinger,
E Pfeffermann,
C Reppin,
L Strueder,
J Truemper,
P Holl,
J Kemmer,
H Soltau,
C Zanthier
Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series; 11/1998
