19/02/09arc meeting, colonster the simbol-x mission and the investigation of hard x-rays from...
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19/02/09 ARC Meeting, Colonster
The Simbol-X mission and the investigation of hard X-rays from massive stars
Michaël De Becker(Groupe d'AstroPhysique des Hautes Energies)
19/02/09 ARC Meeting, Colonster
Outline
Simbol-X in a few words...- Mission concept- Science programme
Potential Belgian scientific participation
Concluding remarks
19/02/09 ARC Meeting, Colonster
Simbol-X: mission concept Main partners: CNES (France), ASI (Italy) + participation of Germany + ???
Formation flight concept:mirror module + detector module Focal length ~ 20 m Mirrors: 100 shells (grazing incidence telescope) Detectors: 2 layers (low energy and high energy)
Ang. Res. < 20 arcsec @ 30 keV Energy range: 0.5 – 80 keV Unprecedented sensitivity in this energy range
19/02/09 ARC Meeting, Colonster
Simbol-X: mission concept Main partners: CNES (France), ASI (Italy) + participation of Germany + ???
Formation flight concept:mirror module + detector module Focal length ~ 20 m Mirrors: 100 shells (grazing incidence telescope) Detectors: 2 layers (low energy and high energy)
Ang. Res. < 20 arcsec @ 30 keV Energy range: 0.5 – 80 keV Unprecedented sensitivity in this energy range
IXO/HXT goal
19/02/09 ARC Meeting, Colonster
Simbol-X: mission concept
Operational considerations
Orbit: - eccentric, with perigee at 20000 km and apogee at 180000 km- four days, with data transfer to ground segment once per orbit
Operation policy: observatory mission, with call for proposals and about 30% of GT
Mission duration: 3 years + provision for 2 years
19/02/09 ARC Meeting, Colonster
Simbol-X: science programme Black holes physics
resolve 50% of the cosmic X-ray background peaking at 30-40 keV investigate Sgr A* and its environment constrain the physics of accretion flows, onto degenerate stars and central galactic black holes
Particle acceleration mechanisms
in relativistic jets of blazars in the strong field of pulsars in supernova remnants in clusters of galaxies
19/02/09 ARC Meeting, Colonster
Potential participationCurrent status of the mission: Simbol-X will enter Phase B this year
Initially: bilateral partnership between CNES and ASI But: after the substantial decrease of the Italian participation, CNES is searching for additional partners : Spain, Switzerland, Polland.... Belgium?
A CNES delegation came to Liège recently in order to present the status of the mission, and to discuss potential Belgian contributions
Potential contributions have been identified both from the technical (CSL) and scientific (GAPHE) point of view....
19/02/09 ARC Meeting, Colonster
Potential participation: science
In the radio domain…Stellar winds produce a thermal emission (free-free emission).In some cases, synchrotron radiationhas been identified (White 1985) presence of a population of relativistic electrons acceleration process at work
Relativistic electrons are present non-thermal emission processes may be considered in the high-energy domain as wellMassive stars are strong UV and visible emitters Inverse Compton scattering is expected to be efficient non-thermal X-ray emission expected : power law !!
Particle acceleration in colliding-wind massive binaries:
19/02/09 ARC Meeting, Colonster
Potential participation: scienceParticle acceleration in colliding-wind massive binaries:
In X-rays…
Stellar winds collide with pre-shock velocities of 2000-3000 km/s hydrodynamic shocks high post-shock temperatures strong THERMAL X-ray emission
The soft X-ray spectrum is dominated by the thermal emission any putative non-thermal emission component will be overwhelmed by the thermal spectrum strong need to investigate the hard X-ray domain
19/02/09 ARC Meeting, Colonster
Potential participation: science
Simbol-X
19/02/09 ARC Meeting, Colonster
Potential participation: science
Catalogues of non-thermal radio emittersO-type: 16 systems
ex: Cyg OB2 #8A (O + O)WR-type: 18 systems
ex: WR140 (WR + O) (see De Becker 2007, A&ARv, 14, 171 for a census of NT emitting massive stars)
+ example of Eta Car: first detection of hard X-rays from a massive star system
19/02/09 ARC Meeting, Colonster
Potential participation: science
Cyg OB2 #8a: O6I + O5.5III, P ~22 d, e ~ 0.24
Simbol-X simulation. The flux of the power law was arbitrarily set to one tenth of the upper limit derived from INTEGRAL-ISGRI observations (see De Becker et al. 2007, A&A, 472, 905)
19/02/09 ARC Meeting, Colonster
Potential participation: science• The issue of the non-thermal emission from colliding-wind binaries
is a relevant science case for Simbol-X, in agreement with the main scientific themes of the mission
• Simbol-X observations, in the context of a broader multiwavelength campaign already well-advanced, are expected to provide crucial information for the understanding of the physics of particle acceleration in colliding-wind massive binaries : hard X-ray flux, spectral index, variation as a function of the orbital phase…
• Relevant targets are already identified
19/02/09 ARC Meeting, Colonster
Concluding remarks• Simbol-X constitutes a very interesting mission with unprecedented
imaging and spectral capabilities in the hard X-ray domain
• A potential Belgian participation is envisaged
• A technical contribution to the payload, or to the characterization of the mirrors, is not excluded (CSL...)
• A relevant scientific contribution has also been identified (GAPHE...)