ATHENA Mission Design and ESA Status. David Lumb ESA Study Scientist MPE Jan 13 th 2012

Transcription

1 ATHENA Mission Design and ESA Status David Lumb ESA Study Scientist MPE Jan 13 th 2012

2 Topics covered ESA L class mission reformulation Current status & programmatics Athena Mission Design Spacecraft Optics X-ray Microcalorimeter Spectrometer Science Figures of Merit

3 Reformulation of L1 Candidate Missions

4 L missions: General status Reformulation phase is completed for the three L mission candidates Europe-only or Europe-led missions. Non strategic international collaboration envisaged, (but with a European back-up) Launch by 2022, => 7 year development Target CaC 850 M e.c Work supported by technical assistance contracts with space industry Was achieved by relying on thorough studies made for the three missions in the last years Technical and programmatic reviews were completed by December 2011

5 ATHENA X-Ray Observatory

6 Mission and space segment evolution Effective area reduced to 1.1 m 1.25 kev Number of mirror modules reduced from 1800 (IXO) to < 500 (Athena) reduces cost Focal length reduced from 20 m to 12 m Fixed structure holding the instruments, deployment mechanism suppressed reduces cost & risk Drastic simplification of the instrumentation Only the two core instruments are maintained: XMS and WFI Additional simplifications in XMS design Two telescope apertures, one for each instrument Focal Plane distribution mechanism suppressed, continuous observation mode for XMS and WFI

7 The ATHENA mission concept +Z - Observatory class mission. +Y +X aft - Large halo orbit at SE-L2, Ariane 5. FPA - X-ray mirrors based on European Silicon Pore Optics technology, HEW 10 arcsec (goal 5 arcsec). FMS SVM FL = 12 m Mirror Assembly - Two identical x-ray mirrors, each illuminating one instrument (WFI, XMS). - Configuration is XMM-Newton like: Focal Plane Assembly (FPA) Fixed Metering Structure (FMS) Service Module (SVM) Mirror Assembly (MA) fore SRE-PA D Lumb - Athena MPE 13/1/2012 7

8 ESA reference design Mass ~ 4.5 ton (A5 capability 6.5 ton) Power ~ 5 kw Focal Plane Assembly Mirror Assembly SRE-PA D Lumb - Athena MPE 13/1/2012 8

9 ATHENA industrial studies The two industrial studies confirmed the feasibility ESA reference design. Spacecraft platform based on demonstrated technologies Comfortable mass margins: 4.5 ton vs 6.5 tons launch capability AIT compatible with existing European facilities SRE-PA D Lumb - Athena MPE 13/1/2012 9

10 Focal Plane Instruments X-ray Micro-calorimeter (XMS) FoV = 2.3 x 2.3 (goal 3 x 3 ) ΔE = 3 (goal 2.5 ev) M = 409 kg P = 1000 W TES detector array 50 mk) No outer array, smaller pixel, relaxed FWHM. Wide-Field Imager (WFI) FoV = 24 x 24 (30 goal) ΔE =150 ev at 6 kev (125eV goal) Si DepFET array 210K) M = 83 kg P = 186 W 10

11 XMS Performance Requirements

12 XMS System

13 XMS Simplification

14 XMS Sensor Status

15 Multiplexor Status

16 XMS - Activities 2012 JAXA funded for Definition Phase to study the Astro-H cooler modifications NASA funded for detailed design work on Athena optimised TES array etc. ESA TRP activity to demonstrate a complete Europeanbased cooler system Nl/Fr/Es/De activities to bring the European heritage solution for XMS sensor and multiplexing to the required TRL

17 Silicon Pore Optics Measurements this week in Berlin

18 Other Activities 2011 To prepare for mass production techniques and implement new production facilities Plate production to IXO requirements, added laser marking for PA, as well as investigate selection of best wafers Coating and bonding for Ir /B 4 C layers, reflectivity data Plate stacking components all updated:plate cleaning, Plate inspection, Plate handling robotic arm, Pre-forming die, Mandrel, Surface metrology All inside class 100 tent and remotely operated

19 Resolution progress

20 Initial Environmental Tests

21 Science Performance

22 A spectacular leap forward As an observatory class X-ray astrophysics mission Athena will provide a spectacular leap forward in scientific capabilities compared with its predecessors (e.g. XMM-Newton, Chandra, Suzaku, ASTRO-H). Athena will impact Astrophysics in the broadest sense, from the solar system to stars, black holes and compact objects, supernovae and their remnants, galaxies, clusters of galaxies, and cosmology. Athena will have enormous potential for breakthrough discoveries that we cannot foresee given our current knowledge of the Universe. Compare Figures of Merit in domains of SPECTROSCOPY, IMAGING and TIMING

23 Spectroscopy

24 Spectroscopy Athena will be capable in terms of high-resolution spectroscopy of detecting weak spectral lines ten times weaker than any of its existing or planned high resolution predecessors Opens the floor to unrivalled astrophysical studies of sources. In comparison with the spatially resolved high-resolution spectroscopy that ASTRO-H calorimeters will enable for the first time, Athena will also bring a much higher spatial resolution bringing new science only attainable with Athena e.g. feedback in cluster cores, the thermal history and velocity structure of clusters, chemical enrichment, SNRs, etc.

25 Spectroscopy - Perseus Core 50ks CHANDRA ACIS ATHENA XMS ASTRO-H SXS

26 Imaging and Surveys Athena s instruments will have a survey capability far better than XMM-Newton and Chandra, thanks to its unique combination of angular resolution, effective area and field of view The limiting flux will be a factor of ~5 fainter than that of XMM-Newton for the same exposure time, and The ultimate sensitivity will be reached at a flux of around 4 x erg cm -2 s -1, one order of magnitude deeper than deepest confusion-limited XMM-Newton exposures. Athena-WFI will detect about 3 times more sources in a single pointing and for the same exposure time, down to virtually the same flux limit as Chandra.

27 Surveys and Imaging

28 Timing Athena will have time resolution a factor >10 better than XMM- Newton (and indeed Chandra and ASTRO-H), and A count rate capability for sources 50 times brighter, therefore enabling spectral-timing studies of the bright sources in the X- ray sky for the first time. E.g. Gravitational redshifts during X-ray bursts An estimate of the redshift (M/R) derived with a few % accuracy if the line broadening is mostly rotational, will constrain the stellar radius through the measured surface velocity (proportional to ΩR). if the neutron star is slowly rotating, then Stark pressure broadening, proportional to M/R 2 is likely to dominate. This implies that from a single detection of a gravitational redshift, in either the rotational or pressure broadening limits, the two unknown M and R can be determined uniquely.

29 Timing Absorption-line spectrum of a 1.4 M and 11.5 km neutron star 1 Crab X- ray burst. Includes the effects of light bending, rotational Doppler splitting, Doppler boosting and gravitational redshift. Red = 140 s exposure and a NS spin of 400 Hz, Blue = 70 s exposure and NS spin of 45 Hz

30 Discovery Space Science case developed for Yellow Book, covers breadth of astrophysics, 2 / 3 of 5 year mission and with expected efficiency leaves substantial fraction for other general observatory science While Athena has been designed to answer the questions posed in the science case, previous experience has shown that order-of-magnitude leaps forward in capabilities will unquestionably reveal new breakthroughs in astrophysical understanding of many phenomena

31 Programmatic Status

32 Proposed Member States Contribution The two instruments XMS and WFI are proposed to be provided by Member States (+ Telescope Scientist & Data Processing Consortium?) Approach similar to that envisaged for IXO Limited international cooperation envisaged for some XMS units: JAXA: XMS cryostat + cryogenic chain, NASA: XMS detector array + last cooling stage, Based on IXO assumption of best TRL European back-up under development for both contributions, especially mitigate NASA risk with system and sensor development activities in 2012 ESA Payload contribution: Telescopes and associated hardware, system AIT

33 Selection Process Yellow Book Science Case is now with the Astronomy Working Group Completed Technical and Programmatic Review (will be reported to the SSAC / SPC later) Costing activities internally at ESTEC, industry and with instrument consortia Cross-checking with delegations that the member states commitments are understood Actively investigating the European XMS solution. Anticipate SPC down selection in April (date TBC) Instrument AO by end year and proceed to Definition Phase

34 The End