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

Foreword Jacques PaulRencontres de Moriond23 January 2001 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. Extreme sources active in the soft-gamma ray band Major points of the presentation Observational status in the soft-gamma ray band

Because of the huge amount of mechanical energy released by SN explosions (~ 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? Supernova Remnants SN keV composite ASCA image Brightest X-ray zones of SN 1006 feature non-thermal spectra. Likely origin: synchrotron emission of relativistic e - up to ~ 100 TeV in a ~ 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 PaulRencontres de Moriond23 January 2001

Pulsars 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 eV. The magnetosphere of a pulsar (highly magnetized neutron star) includes efficient sites of electron acceleration taking advantage of the neutron star spinning down. X-ray image (Chandra) Crab pulsar Acceleration sites Jacques PaulRencontres de Moriond23 January 2001

Microquasars E Galactic longitude Galactic latitude Jacques PaulRencontres de Moriond23 January 2001 SIGMA image of the central region of the Galaxy recorded in the keV band. Bright sources are accreting stellar mass black holes. Radio observations of the source 1E have revealed that accreting black holes can generate powerful bipolar jets of relativistic particles  microquasars. Plasma moving close to the light velocity Strong radio emission Jet of subatomic particles Hard X rays

Jacques PaulRencontres de Moriond23 January 2001 Gamma-Ray Bursts 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. 1. BH disk system 3. Internal shocks 2. Relativistic wind ( Γ > 100)

BeppoSAX CAT Blazars 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 PaulRencontres de Moriond23 January 2001

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. Jacques PaulRencontres de Moriond23 January 2001 PRESENT BeppoSAX to stop soon because of financial issues... HETE-2 to operate up to FUTURE INTEGRAL to be launched in Lifetime: 5 years. AGILE to be launched in Lifetime: 2 years. SWIFT to be launched in Lifetime: 2-3 years.

Gamma-Ray Burst Missions HETE-2 Non imaging keV GRB monitor, 2-25 keV and keV X-ray wide field cameras. Was successfully launched in October SWIFT Imaging keV GRB detector (GRB location < 4’). Survey of the GRB field in X-ray ( keV) and UV- visible ( nm) bands. To be launched in Jacques PaulRencontres de Moriond23 January 2001

Spectrometer SPI Imager IBIS The INTEGRAL Mission Spectroscopy and imaging of 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 PaulRencontres de Moriond23 January 2001 To be launched on April 22, 2002, from Baikonur by a Proton rocket.

Coded Mask Telescope: It Works ! Crab Nebula the standard calibration source for gamma-ray astronomy SIGMA, first coded-mask telescope to operate in the keV band Sky image built in the keV band with a 13’ angular resolution Raw image recorded by the SIGMA position sensitive detector ObservationDéconvolution Jacques PaulRencontres de Moriond23 January 2001

The Imaging Telescope IBIS Distinct detection layers located 3.2 m below a coded mask. ISGRI, an array of 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 ,10 6 s) photon cm -2 s -1 keV -1 Jacques PaulRencontres de Moriond23 January 2001

A polycell First light The IBIS Upper Detector Plane 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. Jacques PaulRencontres de Moriond23 January 2001

IBIS Continuum Sensitivity Energy (keV) σ, 10 6 s, ΔE = E Sensitivity (photon cm -2 s -1 keV -1 ) Jacques PaulRencontres de Moriond23 January 2001

Observing Program Observing time 0% 100% 50% Commissioning phase (2 months) Open time (65%)Open time (70%)75% Core program (35%)Core program (30%)25% LaunchNominal Mission Phase Extended Phase 12 months36 m12 months Jacques PaulRencontres de Moriond23 January 2001

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. Proposal material available via the Internet at: Jacques PaulRencontres de Moriond23 January 2001 AO-1 has been released last November and the due date for proposals is 16 February 2001 (14h GMT).