1. CEA-Saclay, IRFU-Service d’Astrophysique
The SVOM Mission
for GRB Studies
Bertrand Cordier
CEA-Saclay, IRFU-Service d’Astrophysique

2. Prominent questions for the present decade
Astrophysics
How black holes form relativistic outflows?
What was the first stellar population?
How the Universe has been re-ionized?
....…
Physics
Where UHE cosmic-rays are accelerated?
When a source of gravitational waves will be identified?
Can we better constrain the nature of the dark energy?
....…
Advanced GRB studies to provide unique answers

3. What we want to learn
from the SVOM mission

4. Scientific rationale of the SVOM GRB mission
GRB phenomenon
Diversity and unity of GRBs
GRB physics
Acceleration and nature of the relativistic jet
Radiation processes
The early afterglow and the reverse shock
The GRB-supernova connection
Short GRB progenitors
GRB progenitors
Cosmology
Tracing star formation
Re-ionization of the universe
Cosmological parameters
Cosmological lighthouses (absorption systems)
Host galaxies
Cosmology
Tracing star formation
Re-ionization of the universe
Cosmological parameters
Cosmological lighthouses (absorption systems)
Host galaxies
Fundamental
Origin of high-energy cosmic rays
Probing Lorentz invariance
Short GRBs and gravitational waves
physics

5. Scientific rationale of the SVOM GRB mission
CEA-Irfu, IRAP, APC, IAP, Paris, LAM, Obs Strasbourg, LPAG, LUPM, LAL, GEPI, LPC2E, University of Leicester, MPE

6. What we require
for the SVOM mission

7. SVOM scientific instrument arrangement
October 2013
MXT VT
ECLAIRs
GRM
GFT-2
GWAC
GFT-1

8. What we expect from
the SVOM instruments

9. ECLAIRs: the trigger camera
Main characteristics
Coded mask telescope
Wide FOV 2 Sr
6400 CdTe – 1024 cm2
4 keV – 250 keV
Anticipated performances
Loc. accuracy < 10arcmin
80 GRBs / year

10. GRM – The Gamma Ray Monitor
Main characteristics
NaI detectors
FOV : 6 Sr
50 keV – 5 MeV
Anticipated performances
Loc. accuracy ~ 2°
110 GRBs / year

11. MXT – The Multi-channel X-ray Telescope
Main characteristics
Wolter-I X-ray lens
FOV 1 deg2
PN CCD 256x256 75µ
0.3 keV – 10 keV
Anticipated performances
Loc. accuracy < 1 arcmin
20 arcsec for bright GRB
80 GRBs / year

12. VT – The Visible Telescope
Main characteristics
Ф=40cm
FOV 1 : 26 x26 arcmin2
2 X 2048x2048 CCD
400 nm – 950 nm
Anticipated performances
Loc. accuracy < 2 arcsec
Mv = 22.5 in 300s

13. Photometric redshift of high z GRBs
Ground instruments
GWAC
Wavelength coverage:
~ nm
Limiting magnitude:
~ 15 (5σ, 10s)
Overall field-of-view:
~ 90 deg. × 90 deg.
GFT-1
Diameter:
~ 100 cm
Field-of-view:
~ 23 arcmin × 23 arcmin
Wavelength coverage:
~ nm
GFT-2
Diameter:
~ 100 cm
Field-of-view:
~ 30 arcmin × 30 arcmin
Photometric band:
B V R I J H
Photometric redshift of high z GRBs

14. A gold plated example from SWIFT satellite
On 04/23/09 (07:55:19 UT): Swift/BAT triggers on a long GRB (GRB )
σPosition ≈ 3 arcmin
SWIFT XRT
SWIFT BAT
T + 72 sec: Swift/XRT start observations
σPosition ≈ 2.3 arcsec
T + 16h: photometric indication of a very high redshift by 2.2m MPE telescope
σPosition < 1 arcsec & z ≈ 8.1±0.4
T h: spectroscopic confirmation of the redshift by ESO/VLT
z ≈ 8.26±0.07
→ ECLAIRs
→ MXT
→ VT & GFTs
→ Suivi

15. SVOM multi-wavelength capabilities
102
103
104
105 10 1 -5
1022
1020
1016
1018
1014
1015
Time (s)
Log. scale
Time (m)
Lin. scale
Frequency (Hz)
Space
Ground
Slew
GRM
ECLAIRs
MXT VT
GWAC
GFT-1
GFT-2
Space and ground instruments join to enable a unique coverage

16. Mission requirements

17. SVOM Pointing Strategy
Sun
Night side
SVOM orbit (i ~ 30°)
Most of the GRBs detected by SVOM to be well above the horizon
of large ground based telescopes all located at tropical latitudes

18. SVOM- attitude law anti solar ECLAIRs FOV roque de los muchachos
maunea kea
SCO X1
anti solar
GALACTIC PLANE
Cerro Paranal
ECLAIRs FOV

19. Prompt Dissemination of GRB Parameters

20. SVOM Observation Strategy
Space
ECLAIRs and GRM observe the prompt X/gamma emission
GRB trigger provided by ECLAIRs at timeT0
multi messenger follow-up
Robotic telescopes
T0 + 1 min
GFTs (B, V, R, I, J, H band)
VT (V and R bands)
MXT (soft X-rays)
T min
Ground
GWAC (prompt in the V band)

21. SVOM and the GW
The coalescence of compact binary system is supposed to be an effective source of gravitational waves detectable by the advanced version of the ground based gravitational-wave detectors LIRGO and Virgo.
2017
2019
2022
The ground based detectors LIGO and Virgo are rapidly improving in sensitivity and localization.
In the network should be able to detect the likely binary neutron collapse up to 450Mpc within an error box of few deg2.
Expected NS-NS mergers detection rate: about 40/year within 445 Mpc (z~0.1)
Expected BH-NS mergers detection rate: about 10/year within 927 Mpc (z~0.2) (Abadie et al. 2010)
Thanks to MXT, SVOM has a good probability to detect and localise a GW event associated to a short GRB

22. SVOM Science Management Plan
The scientific exploitation of the SVOM mission is organized as follows:
Three main categories:
1- The Core Program : GRB science
1.1- The Burst Advocates
1.2- Key programs
1.3-Exceptional GRBs
2- The General Program : Non-GRB science
2.1- Pointed narrow-field observations
2.2- Wide-field surveys
3- Targets of Opportunity
Chinese and French scientists have a complete access to the data provided by all SVOM instruments. The publications involving SVOM data are submitted to a rule respecting a ratio China/France

23. Road MAP
Mars 2014 dégel de la mission SVOM –> lancement 2020
Juin 2014 signature du MOU entre le CNES et la CNSA
le statut du télescope X
nos droits sur les données
Eté 2014 kick-off phase B mission SVOM
Fin été 2014 réunion scientifique SVOM France
Fédérer la communauté SVOM France
Présentation du Science Management Plan
Préparer le suivi des alertes
Préparer la science hors-sursaut

24. University of Leicester
NAOC, Beijing
IHEP, Beijing
XIOPM, Xi’an
SECM, Shanghai
CEA-Irfu, Saclay
IRAP, Toulouse
APC, Paris
IAP, Paris
LAM, Marseille
Obs Strasbourg
LPAG Grenoble
LUPM Montpellier
LAL Orsay
GEPI Meudon
LPC2E Orléans
University of Leicester
MPE, Garching
CNES, Toulouse
GO SVOM !
Expected launch 2020
Phase B kick-off 2014

25. 谢谢
Thank you