eROSITA extended ROentgen Survey with an Imaging Telescope Array
Peter Predehl on behalf of the eROSITA team:
Co-Is: Hans Böhringer, Ulrich Briel, Hermann Brunner, Evgeniy Churazov, Michael Freyberg, Peter Friedrich, Günther Hasinger, Eckhard Kendziorra, Dieter Lutz, Norbert Meidinger, Mikhail Pavlinsky, Andrea Santangelo, Jürgen Schmitt, Axel Schwope, Matthias Steinmetz, Lothar Strüder, Rashid Sunyaev, Jörn Wilms
System Engineer: Josef Eder Product Assurance: H. Bräuninger, M. Hengmith Electronics Engineering: W. Bornemann, O. Hälker, S. Hermann, W. Kink, S. Müller, Th. Schanz, O. Hans Mechanical Engineering: H. Huber, Chr. Rohé, L. Tiedemann, R. Schreib, B. Mican, K. Lehmann, H. Eibl, F. Huber, R. Sandmair Mirror System, PANTER: P. Friedrich, W. Burkert, M. Freyberg, B. Budau, V. Burwitz Cooling, Thermal Engineering: M. Fürmetz CCD-Camera: N. Meidinger, Robert Hartmann, E. Pfeffermann, G. Schächner, J. Elbs, S. Ebermayer Attitude: A. Schwope Calibration, Analysis: G. Hartner, K. Misaki, U. Briel, K. Dennerl, R. Andritschke, Chr. Tenzer Laboratory, Tests: M. Vongehr, L. Hirschinger, K. Dittrich, F. Schrey Ground Software, Simulation: H. Brunner, N. Cappelluti, G. Lamer, M. Mühlegger, J. Wilms, I. Kreykenbohm, Chr. Schmid Mission Planning: J. Schmitt, J. Robrade Institutes: Industry: Max-Planck-Institut für extraterrestrische Physik, Garching/D Kayser-Threde/D Mirror System Space Research Institute IKI, Moscow/Ru Media Lario/I Mirror Modules Univ. Tübingen/D Carl Zeiss/D Mirror Mandrels Univ. Hamburg/D Invent/D Telescope Structure Univ. Erlangen-Nürnberg/D pnSensor/D CCDs Astrophysikalisches Institut Potsdam/D ... Max-Planck-Institut für Astrophysik/D Historical Development
ROSAT 1990-1998
Spectrum-XG First X-ray all-sky survey Jet-X, SODART, etc. with an imaging telescope
Negotiations between Roskosmos and ESA ABRIXAS Bundle of 7 small telescopes on a "new" Spectrum-XG mission (2005) To extend the all-sky survey towards higher energies MoU between Roskosmos and DLR (2007) 1999 Spektr-RG ABRIXAS science on the Launch: 2012 International Space Station ROSITA 2002 eROSITA
Dark Energy 105 Clusters of Galaxies Design Driving Science
• Extragalactic Survey (20.000 • Detection of 100.000 Cluster sqd, 2yrs) of Galaxies to test • Deep Survey (200 sqd, ½ yr) cosmological models • Pointing (1 yr)
hidden AGN • All-sky Survey (1 yr) • lot of additional science + add. pointing (lifetime) eROSITA ABRIXAS • Increase of effective area – 27 Æ 54 mirror shells per module (7) • Increase of Field of View –2×2cm2 Æ 3×3cm2 (61 arcmin) Why are we doing this in X-rays?
In X-rays we see clusters as one continuous entity
COSMOS Field XMM-Newton Most cosmological studies involving galaxy clusters are based on X-ray surveys What can we do with 100,000 clusters?
1. Cluster mass function N(M,z) depends mainly on the matter density Ωm and the amplitude of the primordial power spectrum σ8 2. Evolution N(M,z) gives sensitive constraints on DM and DE 3. Cluster power spectrum amplitude and shape depend on DM and DE 4. Baryonic wiggles due to acoustic oscillations at recombination give tight constraints on space curvature at different epochs 5. Cluster baryon fraction as function of z gives constraints on DM and DE 6. Clusters provide direct distance measurements due to combined X- ray and SZ-measurements Galaxy Clusters known today • ~ 200 – 300 from Einstein (1978 – 1981) • ~ 1000 published from ROSAT (1990 -1998) • ~ 1000 to be published from reanalysis of ROSAT data • ~200 – 300 from XMM-Newton archival data • + 10 – 15 with redshift > 1
Cluster Surveys
Expected: >100.000 clusters (DE!) ~100 clusters @ z>1.5
4yr
eROSITA ½yr
COSMOS Cluster Number Density (z)
eROSITA deep survey: -15 -1 -2 Fx = 5 × 10 erg s cm
-14 -1 -2 eROSITA all-sky survey: Fx = 5 × 10 erg s cm
M. Mühlegger, 2008 eROSITA Sensitivity Grasp F/Ω
4yr eROSITA ½yr
Expectation: 100.000 clusters (DE!) ~100 clusters @ z>1.5 7 telescopes, 350 cm2 each 3 Million AGN [450,120, 36, 10] @ z > large field of view (61 arcmin Ø) [ 6, 7, 8, 9] ~ 2 × XMM-Newton (MOS+PN) Mission Scenario
galactic plane
ecl iptic
galactic pole
ecliptic pole Programmatic Status
• June 2006 Proposal to DLR • Sep. 2006 Mirror-QM Contracts (MPG funded) • Nov. 2006 Mission Definition Review (DLR) • Dec. 2006 Request for Funding to DLR • Mar. 2007 Approval by DLR • Mar. 2007 MoU between Roskosmos & DLR • April 2007: eROSITA approved and funded by DLR • October 2007: Detailed Agreement between DLR and Roskosmos • November 2007: System Requirements Review (DLR) • June 2008: Mirror-FM Contract (LLI parts) • August 2008: Structure Contract (Engineering Support)
• Partly on hold due to payload & orbit discussions • Spektr-RG will be launched in 2012.
• The orbit will be at L2.
• The payload contains eROSITA (D) and ART-XC (Ru).
• eROSITA is the core instrument
• The Detailed Agreement (DLR-Roscosmos) will be signed soon 50:50 Share of Data (Ru/D)
CAELUM EROSITAE CUM RETICULO AEQUATORIALI
HERCULES URSA DRACO BOOTES URSA MAIOR MINOR
LE CEPHEUS VIRGO O CASSIOPEIA CYGNUS AURIGA AQUILA GEMINI PERSEUS ANDROMEDA SCORPIUS PEGASUS SAGITTARIUS CENTAURUS TAURUS ORION VELA CRUX CANIS MAIOR AQUARIUS CARINA
HEMISPHAERA ORIENTALIS HEMISPHAERA OCCIDENTALIS
INVESTIGATIO RADIORUM CAELIS ROENTGENIENSIS AB ANNO MMXII Mirror System
• 7 Mirror Modules, 54 shells each, 360mm Ø, f=1.600mm • inner 27 shells to be replicated from old ABRIXAS mandrels • 3 outer mandrels already manufactured (#1, #2, #27) CCD-Module
CCD Module (breadboard version) Measurements at C Kα (277eV) and Mn Kα (5,9 The CCDs have 384 × 384 pixels in both keV) on flight- CCDs (2cm ×2cm) show the image and framestore area. expected energy resolution and low energy Pixelsize: 75µm. response. Cycle time: 50msec
Cooling required (-80°C) Telescope Structure
• CFRP Honeycomb Structure • leightweight • thermally stable
• Hexapod Mounting • no thermal/mechanical stresses induced on structure
• Sunshield
• startracker mounted on structure eROSITA Simulations by Chr. Schmid
Pointing Survey Off-axis blurring of a Wolter-I telescope Æ PSF has to be averaged over the FoV eROSITA Image Simulator M. Mühlegger, N. Cappelluti
Input components: • AGN: logN-logS from COSMOS (Cappelluti 2007, positions randomly) • Background: estimation for L2-Orbit • Cluster of galaxies: lightcone by M. Roncarelli, F. Pace from cosmological simulations by S. Borgani (2004)
Processing: • Poissonization Æ event list • PSF convolution Æ redistributed event list • Binning Æ output image with specified pixel size
Including: Not including (so far):
• Variable CXB • Mass function N(M,z) → N(LX,z), assuming given L -M relation • Image simulations X • Source detection tests • nH distribution • Completeness • LX-T relation: C(T,z,nH) → C(LX,z,nH) → counts eROSITA Image Simulator by Martin Mühlegger, N. Cappelluti eROSITA Simulations
Surface brightness map (1° × 1,6°) eROSITA Simulations
Same region, clusters only, 100ks, PSF convolved eROSITA Simulations
Same region, A+B+C, 3ks, PSF convolved Cluster Detection M. Mühlegger Follow-up Observations
The achievement the eROSITA primary (extragalactic) scientific goals requires the knowledge of the redshift of the X-ray sources. The X-ray spectrum can consistently provide the redshift only for a minority of the sources (~3-10% at most?) Substantial optical/near-IR follow-up (or companion surveys) required for the redshift identification and source characterization
→ Overview of relevant optical/near-IR facilities/surveys Conclusion
• eROSITA is completely approved and funded • Open issues concerning payload and orbit are solved • Project is in parts already in phase C/D • Ground software for data analysis (SASS and NRTA) is going on • Simulations are going on
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