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High energy perspectives (and conclusions). Philippe Ferrando APC Laboratory (UMR 7164) - Service d’Astrophysique CEA/Saclay. APC Conference High Energy Phenomena in the Galactic Center June 17, 2005. The Galactic Centre : an exciting and growing field.
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High energy perspectives (and conclusions) Philippe Ferrando APC Laboratory (UMR 7164) - Service d’Astrophysique CEA/Saclay APC Conference High Energy Phenomena in the Galactic Center June 17, 2005
The Galactic Centre : an exciting and growing field Exciting : • closest look we can have to a Super Massive Black Hole and its complex surroundings in the Universe - Potential link with more distant AGNs • potentially harboring dark matter, UHE cosmic-ray accelerator… Growing : New high quality high energy data : • X-rays [0.1–10 keV] Chandra & XMM–Newton 1999 -… • g-rays [0.02-10 MeV] Integral 2002 - • TeV g-rays [0.1–20 TeV] HESS 2003 - Multi Wavelength Campaigns with radio and NIR
Chandra & XMM–Newton High throughput : detailed spectro-imaging up to 10 keV Angular resolution : resolving this complex region, and measuring the quiescent spectrum of SgrA*
Sulphur K Fe K 6.7 keV 4-6 keV +0.5° Chandra and XMM–Newton Sensitivity : acces to short time variability Galactic Latitude X-ray flares from SgrA*, look for periodicity… Continuum subtracted line emission Radio VLA
INTEGRAL Sensitivity and angular resolution : mapping this complex region 20-30 keV 30-40 keV 40-60 keV 60-85 keV • IBIS/ISGRI mosaics in different energy bands: spectrum 20-120 keV • Possible shift of the central source between Sgr A and 1E1743
HESS H.E.S.S. Preliminary Sensitivity, angular resolution, large Field of View
But questions still open… What makes the 6.4 keV line ? Nature of hot component ? Origin of the large scale 511 keV line ?
But questions still open… Integral Integral Spectrum of SgrA* ? Are Ultra High Energy Cosmic Rays accelerated at the GC ? How many sources ?
What can we count on for sure ? AUGER GC and AGASA/Sugar prime targets Completion in 2006 Unprecedented statistics expected Angular resol. 0.5–1° ? GC 15° Gamma-ray sources and UHECR connection AGASA excess map in the a posteriori energy band [1017.9 – 1018.3] eV
What can we count on for sure ? Gamma-ray - Neutrinos connection ANTARES Completion in 2007 Max of signal expected @ ~ 10 TeV Very low bckgd for point sources Angular resol. @ 10 TeV ~ 0.2° Expected rate (HESS) very low 0.02 evt/year but surprises possible… Clear need for a km3 experiment in a longer term
What can we count on for sure ? Anticoincidence SuperAGILE Si tracker Mini- Calorimetre AGILE gamma-ray telescope Small ASI mission - launch date early 2006 GRID : E-range : 30 MeV – 30 GeV FoV 2.5 sr Dq 36 arcmin @ 1 GeV Improve EGRET error box radius by a factor of 2
What can we count on for sure ? The GLAST mission : launch mid 2007 GLAST/LAT EGRET E range : 0.02 -300 GeV 0.02-30 E resolution : 10 % 10 % Eff. Area : 8000 cm2 1500 Field of view > 2 sr 0.5 sr Ang. Resol. ~ 3o @ 100 MeV 5.8° ~ 0.15o > 10 GeV Sensitivity <6 x 10-9 cm-2 s-1 ~ 10-7 Source locat. 0.5 - 5 arcmin 5–30 Orders of magnitude improvement upon EGRET
What can we count on for sure ? Upgrade : HESS II • Lower threshold to extend the energy-range in mono-telescope mode • Better sensitivity at high energies in stereo Atmospheric Cerenkov (stress on HESS but also MAGIC, VERITAS, CANGAROO) Reduce GC source position uncertainty now 4'' ± 10''stat ± 20''syst from Sgr A* (1 pc)
What can we count on for sure ? Full spectral coverage in gamma-rays ! • Connection space-ground • Variability
And in a longer term ? An absolute necessity : get the angular resolution and the sensitivity down by orders of magnitude above 10 keV
0.0° XMM-Newton GC Survey 0.3-9 keV (Belanger et al 2005, in prep.) (Decourchelle et al. 2003) 0.0° INTEGRAL GC Survey 20-40 keV Sgr A Sgr B2 0.0° 1.0° 359.0°
The 10 keV sensitivity gap reason XMM–Newton INTEGRAL 0.1–10 keV : focusing optics Spatial resolution : 15 arcsec High signal to noise 15 keV–10 MeV : coded masks Spatial resolution : 12 arcmin Moderate signal to noise
The necessary future : use focusing optics as in longer wavelengths Focusing using a grazing incidence nested shells Wolter I mirror • Long focal length for high reflectivity at high energy In hard X-rays : feasible on a large energy range by extension of the « usual » soft X–rays techniques Projects NuSTAR and SIMBOL-X
The Simbol-X mission Basically : long focal length telescope, using grazing incidence X–ray optics, with mirror and detectors mounted on two different spacecraft in formation flying. Characteristics Energy range : 0.5–70 keV Resolution : < 130 eV @ 6 keV, 1 % @ 60 keV Angular resol. : < 30 arcsec (local. < 3 arcsec) Effective area : > 550 cm2 E < 35 keV 150 cm2 @ 50 keV Sensitivity : 5 10-8 ph/cm2/s/keV (E < 40 keV) (5 s, 100 ks, DE = E/2)
Optics (nominal) Shell diameters : 290 to 600 mm Focal length : 30 m Angles : 0.07° to 0.142° Shell thickness : 0.12 to 0.30 mm Number of shells : 100 Total mass : 213 kg Dq : ~ 30’’ HEW FOV : ~ 6 arcmin 580 cm2 @ 30 keV • Direct heritage from XMM–Newton • Long focal length for high reflectivity at high energy • Nickel shells with single layer Pt coating, obtained by well proven electroforming replication method • Low mass obtained via a reduced thickness of shells
Focal plane < 17 keV > 17 keV SDD CdZnTe SDD CdZnTe Anticoincidence (BGO) Optical filter (0.1 mm Al) Low energy detector (450 mm Silicium) High energy detector (2 mm Cd(Zn)Te) Requirements • Pixel size of ~ 500 mm (gives good oversampling of the 4.4 mm PSF) • Full diameter of focal plane : 6 cm • Fast response detectors for full anticoincidence scheme • Avoid constraining cooling • Low energy response down to 0.5 keV • Good spectral resolution for Iron line
Sensitivity XMM SIMBOL-X INTEGRAL 1 arcmin diameter region, 1 Ms exposure, DE = E/2
in 2012 with Simbol-X The central 2 degrees > 20 keV today INTEGRAL GC Survey 20-40 keV Sgr A Sgr B2 0.0° 1.0° 359.0°
Testing accretion models with SIMBOL-X SIMBOL-X 3 s, 1 hour • Measurement of spectra for a large range of flare intensities •Access to the high energy range, discriminating models •Quiescent spectrum at ~ 40 keV Liu & Melia, 2002
Galactic Centre Diffuse Emission (Decourchelle et al. 04)
Galactic Centre seen by SIMBOL-X (A. Decourchelle & J. Ballet) Spectrum in a 1 arcmin2 region Exposure time = 84 ks Simulation > 10 keV, 10 x 10 arcmin2 Total exposure = 300 ks
Simbol–X status • Consortium led by France with a strong Italian involvment, and a firm participation of Germany • Mission proposed early 2004 to CNES in response to a call for scientific missions using spacecrafts in formation flying • Selected by CNES for phase 0 assessment (4 missions kept) • Phase A start, autumn 2005 (2 missions kept) •Selection end 2006 (1 mission kept) • Launch date : 2012 - 2 years of science observations
Conclusions The Galactic Centre an exciting and growing field, with a rich future ! A lot of important results to come in the next years, but will not solve all questions A deeper look possible early next decade with currently designed new generation of instruments