jacques paul soft gamma-ray astronomy 23 january 2001 rencontres de moriond les arcs expected impact...
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Jacques Paul
Soft Gamma-Ray AstronomySoft Gamma-Ray Astronomy
23 January2001
Rencontres de MoriondLes Arcs
Expected Impact on VHE PhenomenaExpected Impact on VHE PhenomenaPanorama in the Coming YearsPanorama in the Coming Years
INTEGRAL Mission Scientist
CEA/DSM/DAPNIA/Service d'AstrophysiqueCEA-Saclay, France
ForewordForeword
Jacques Paul Rencontres 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 (~ 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?
Supernova RemnantsSupernova Remnants
SN 10060.4-8 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 ~ 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 Moriond23 January 2001
PulsarsPulsars
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.
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 Paul Rencontres de Moriond23 January 2001
MicroquasarsMicroquasars
0 3564
0
4
1E 1740.7-2942
Galactic longitude
Ga
lact
ic la
titu
de
Jacques Paul Rencontres de Moriond23 January 2001
SIGMA image of the central region of the Galaxy recorded in the 75-150 keV band. Bright sources are accreting stellar mass black holes.
Radio observations of the source 1E 1740.7-2942 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 particlesHard X rays
Jacques Paul Rencontres de Moriond
23 January 2001
Gamma-Ray Bursts 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
BlazarsBlazars
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 Moriond23 January 2001
Observation Status (50 keV-5 MeV)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 Paul Rencontres de Moriond23 January 2001
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.
Gamma-Ray Burst MissionsGamma-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 Moriond23 January 2001
Spectrometer SPI
Imager IBIS
TheThe INTEGRAL INTEGRAL MissionMission
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 Paul Rencontres de Moriond23 January 2001
To be launched on April 22, 2002, from Baikonur by a Proton rocket.
Coded Mask Telescope: It Works !Coded Mask Telescope: It Works !Crab Nebula the standard
calibration source for
gamma-ray astronomy
SIGMA, first coded-mask telescope to
operate in the 30-1300
keV band
Sky image built in the 40-75 keV band with a 13’ angular resolution
Raw image recorded by the SIGMA position sensitive detector
Observation Déconvolution
Jacques Paul Rencontres de Moriond23 January 2001
The Imaging Telescope IBISThe Imaging Telescope IBISDistinct 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 range 20 keV-10 MeVField of view 9° x 9° (fully coded)
Source location determination < 1’Energy resolution 7% at 100 keV
100 keV sensitivity (3,106 s) 4 10-7 photon cm-2 s-1 keV-1
Jacques Paul Rencontres de Moriond23 January 2001
A polycell
First light
The IBIS Upper Detector PlaneThe 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 Paul Rencontres de Moriond23 January 2001
IBIS Continuum SensitivityIBIS Continuum Sensitivity10-5
10-6
10-7
10-8
10-9
100 1000
Energy (keV)
10000
3σ, 106 s, ΔE = E
Se
nsiti
vity
(p
hot
on
cm
-2 s
-1 k
eV
-1)
Jacques Paul Rencontres de Moriond23 January 2001
Observing ProgramObserving Program
Obs
ervi
ng t
ime
0%
100%
50%
Com
mis
sion
ing
phas
e (2
mon
ths)
Open time (65%) Open time (70%) 75%
Core program (35%) Core program (30%) 25%
Launch Nominal Mission Phase ExtendedPhase
12 months 36 m12 months
Jacques Paul Rencontres de Moriond23 January 2001
Access to Access to INTEGRALINTEGRAL
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:http://astro.estec.esa.nl/Integral/isoc
Jacques Paul Rencontres de Moriond23 January 2001
AO-1 has been released last November and the due date for proposals is 16 February 2001 (14h GMT).
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