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Jacques Paul

Soft Gamma-Ray Astronomy. Expected Impact on VHE Phenomena Panorama in the Coming Years. Jacques Paul. INTEGRAL Mission Scientist CEA/DSM/DAPNIA/Service d'Astrophysique CEA-Saclay, France. 23 January 2001. Rencontres de Moriond Les Arcs. Foreword.

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Jacques Paul

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  1. Soft Gamma-Ray Astronomy Expected Impact on VHE Phenomena Panorama in the Coming Years Jacques Paul INTEGRAL Mission Scientist CEA/DSM/DAPNIA/Service d'Astrophysique CEA-Saclay, France 23 January 2001 Rencontres de Moriond Les Arcs

  2. Foreword Contrarily to the great majority of celestial bodies which radiate mostly in a narrow spectral band (thermal emission), cosmic sites of high-energy phenomena generate non-thermal radiation in a wide spectral domain. Cosmic sites of high-energy phenomena should then be observed not only in the very high-energy photon band but also over a very large spectral domain. Simultaneous observations performed in both X-ray and gamma-ray spectral domains remain however the privileged means – sometimes the only one – to study the profound mechanisms of cosmic high-energy phenomena. Major points of the presentation Extreme sources active in the soft-gamma ray band Observational status in the soft-gamma ray band Jacques Paul Rencontres de Moriond 23 January 2001

  3. Supernova Remnants Because of the huge amount of mechanical energy released by SN explosions (~ 1051 ergs), it has long been thought that shock waves induced by supernova explosions are responsible for the acceleration of cosmic rays up to energies ~ 100 TeV. Observational clues? 0.4-8 keV compositeASCA image SN 1006 Brightest X-ray zones of SN 1006 feature non-thermal spectra. Likely origin: synchrotron emission of relativistic e- up to ~ 100 TeV in a ~ 10-5 G magnetic field. In agreement with TeV gamma-ray observations. Primordial role of SNR observations in the hard X rays / soft gamma rays to characterize non-thermal emission. Jacques Paul Rencontres de Moriond 23 January 2001

  4. Pulsars The magnetosphere of a pulsar (highly magnetized neutron star) includes efficient sites of electron acceleration taking advantage of the neutron star spinning down. Crab pulsar Acceleration sites The wind of relativistic electrons released by the pulsar produces a strong relativistic shock when interacting with the surrounding medium  site of particle re- acceleration up to 1015 eV. X-ray image (Chandra) Jacques Paul Rencontres de Moriond 23 January 2001

  5. Microquasars SIGMA image of the central region of the Galaxy recorded in the 75-150 keV band. Bright sources are accreting stellar mass black holes. 4 Galactic latitude 1E 1740.7-2942 0 Plasma moving close to the light velocity Strong radio emission 4 0 356 Galactic longitude Radio observations of the source 1E 1740.7-2942 have revealed that accreting black holes can generate powerful bipolar jets of relativistic particles  microquasars. Jet of subatomic particles Hard X rays Jacques Paul Rencontres de Moriond 23 January 2001

  6. Gamma-Ray Bursts 2. Relativistic wind (Γ > 100) 3. Internal shocks 1. BH disk system An initial event leads to a stellar BH surrounded by a thick debris torus. A fraction of the energy from the disk and/or the rotating BH is injected into a relativistic wind. Internal relativistic shocks are produced when a “rapid” wind layer catches up with a slower one. Gamma rays are radiated by highly relativistic electrons accelerated behind the shocks  simultaneous low-energy / high energy observations. Jacques Paul Rencontres de Moriond 23 January 2001

  7. Blazars BeppoSAX CAT 16/04 07/04 Mrk 501 April 1997 Jet models, such as the synchrotron-self-Compton process, require Compton scattering of soft photons by relativistic electrons in the jet. The low-energy photons can originate as synchrotron emission from within the jet  simultaneous low-energy / high energy observations. Jacques Paul Rencontres de Moriond 23 January 2001

  8. Observation Status (50 keV-5 MeV) PAST CGRO (including the three low-energy gamma-ray detectors OSSE, BATSE and COMPTEL) has been de-orbited on June 3rd, 2000, because of failure of gyro # 3. PRESENT BeppoSAX to stop soon because of financial issues... HETE-2 to operate up to 2003. FUTURE INTEGRAL to be launched in 2002. Lifetime: 5 years. AGILE to be launched in 2002. Lifetime: 2 years. SWIFT to be launched in 2003. Lifetime: 2-3 years. Jacques Paul Rencontres de Moriond 23 January 2001

  9. Gamma-Ray Burst Missions HETE-2 Non imaging 6-400 keV GRB monitor, 2-25 keV and 0.5-14 keV X-ray wide field cameras. Was successfully launched in October 2000. SWIFT Imaging 10-150 keV GRB detector (GRB location < 4’). Survey of the GRB field in X-ray (0.2-10 keV) and UV-visible (170-650 nm) bands. To be launched in 2003. Jacques Paul Rencontres de Moriond 23 January 2001

  10. The INTEGRAL Mission To be launched on April 22, 2002,from Baikonurby a Proton rocket. Spectrometer SPI Imager IBIS Spectroscopy and imagingof sources in the 15 keV-10 MeV band with source monitoring in the X-ray (3-35 keV) and visible (550 nm) bands. Worldwide collaboration including ESA (satellite), European scientific institutes (payload), Russia (launcher) and US (TM station). Jacques Paul Rencontres de Moriond 23 January 2001

  11. Coded Mask Telescope: It Works ! Crab Nebula the standard calibration source for gamma-ray astronomy Sky image built in the 40-75 keV band with a 13’ angular resolution Observation Déconvolution SIGMA, first coded-mask telescope to operate in the 30-1300 keV band Raw image recorded by the SIGMA position sensitive detector Jacques Paul Rencontres de Moriond 23 January 2001

  12. The Imaging Telescope IBIS Distinct detection layers located 3.2 m below a coded mask. ISGRI, an array of 16384 CdTe pixels. PICsIT, an array of 4096 CsI pixels. Both detectors shielded by BGO scintillators. Energy range20 keV-10 MeV Field of view9° x 9° (fully coded) Source location determination< 1’ Energy resolution7% at 100 keV 100 keV sensitivity (3,106 s)4 10-7 photon cm-2 s-1 keV-1 Jacques Paul Rencontres de Moriond 23 January 2001

  13. The IBIS Upper Detector Plane A polycell One of the eight modules of the IBIS low energy detector plane, made of 128 polycells, each being an array of 4 x 4 CdTe semi-conductors. First light Jacques Paul Rencontres de Moriond 23 January 2001

  14. IBIS Continuum Sensitivity 10-5 10-6 Sensitivity (photon cm-2 s-1 keV-1) 10-7 3σ, 106 s, ΔE = E 10-8 10-9 100 1000 10000 Energy (keV) Jacques Paul Rencontres de Moriond 23 January 2001

  15. Observing Program 100% Open time (65%) Open time (70%) 75% Observing time Commissioning phase (2 months) 50% Core program (35%) Core program (30%) 25% 0% 12 months 12 months 36 m Extended Phase Launch Nominal Mission Phase Jacques Paul Rencontres de Moriond 23 January 2001

  16. Access to INTEGRAL INTEGRAL is a real observatory, fully open to a very wide Scientific Community of astronomers, particle physicists, nuclear physicists… In spite of the special nature of the scientific devices (coded aperture), non-specialists should have an easy access to the physical parameters of the target sources. The Announcement of Opportunity includes necessary tools and documentation to allow non-specialists to prepare competitive proposals. AO-1 has been released last November and the due date for proposals is 16 February 2001 (14h GMT). Proposal material available via the Internet at: http://astro.estec.esa.nl/Integral/isoc Jacques Paul Rencontres de Moriond 23 January 2001

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