Status of the INTEGRAL satellite Ken Ebisawa (INTEGRAL Science - - PDF document

Status of the INTEGRAL satellite

Ken Ebisawa (INTEGRAL Science Data Center, NASA/GSFC)

INTErnational Gamma-RAy Laboratory

ESA mission (decided in 1993, part of ESA Horizon

2000)

With US participation

Gamma-ray imager (IBIS) and Spectrometer (SPI),

and X-ray monitor cameras (JEMX)

Coded mask instruments Covers 2 keV to 8 MeV Also optical monitor camera (OMC)

High position resolution with IBIS(~12 arcmin FWHM)

with medium energy resolution

High spectral resolution with SPI (E/∆E~500)

with low spatial resolution

Launched Oct. 17, 2002 by Proton rocket from Baikonur

IBIS SPI JEMX

Detectors Masks

INTEGRAL orbit

High eccentric 72 hour

• rbit

Inclination 51.6˚ Perigee ~9,000 km,

Apogee ~150,000 km

Ground stations

Goldstone (California) Redu (Belgium)

Real time operation

GRB alerts!

Imager IBIS

Mask CdTe layer (ISGRI) CsI layer (PICIST)

Same mask, two detector

layers

• Full imaging capability
• FWHM~12 arcmin

ISGRI (20-200 keV)

• 128x128 CdTe pixels

PICSIT (100-6000 keV)

• 64x64 CsI pixels

Spectrometer SPI

Coded mask and 19 Ge

detectors

Stirling cryocooler Limited imaging

capability(19 “pixels”)

BGO anti-coincidence

detectors

Energy resoluvtion ~2.2

keV@662 keV

Energy range 15 keV to

8 MeV

X-ray monitor JEMX

Two identical detectors Imaging micro-strip gas

chambers(90% Xenon + 10 % Methane)

Energy range 3-35 keV ~30’’ angular resolution

Sensitivity

Limited by systematics 1mCrab at 100 keV, 0.1 Crab at 1 MeV (for continuum, point

source)

Excellent line sensitivity for diffuse sources with SPI

SPI fully coded FOV IBIS fully coded FOV (9˚x9˚) JEMX IBIS partially coded FOV (30˚x30˚)

Large FOV

Dithering and “Sceince Windows”

SPI imaging

capability is limited → “dithering”

• bservation

Observation is

split into many pointings (“Science Windows”)

Each ScW is ~30

minutes

Operation

INTEGRAL Science Operation

Center (ISOC) takes care of the planning

Mission Operation Center

(MOC) will send commands and receive telemetry

ISDC takes care of downstream

Receiving telemetry Conversion to FITS Develop analysis software for

users

Distribution of the data and

software to INTEGRAL users

Archive data, and user support

Oct 17, 2002

INTEGRAL observations

”Core” observation program

Galactic Plane Scan Galactic Center Deep Exposure Vela region Transient sources (TOO)

Guest Observer program

AO1 program being performed

Gamma-ray bursts (IBAS)→GCN Quick Look Analysis and alerts→IAUC

Galactic Plane Survey

Total ~2M sec with

~1700 Pointings

Covers the entire

plane with |b|<25˚

Carried out once

per every week for

• ver ~60 ˚ in

longitude

simulation

Galactic Center Deep Exposure

Total ~4 M sec, ~1000 pointings |l|< 30˚ , |b|<30˚

simulation

Other core programs (~3 Msec)

Vela region Mrk 501 GX339-4 1E 1740-2942 GRS1915+105 GRO J1655-40 Cyg X-1, Cyg X-3 SN Ia, II, classical nova new X/gamma-transients

Guest Observer program

AO1 in 2001 February Completely open to the world Total ~110 proposals accepted

ESA countries, USA, Russia, Japan….

Data will be public in one year (as well as the

core program data)

INTEGRAL Burst Alert System (IBAS)

Near real time distribution of the positions of

GRBs detected by INTEGRAL

Fully automated and checks the real-time

telemetry

Search for GRBs with different time scales If confirmed, alerts are automatically sent to

GRB Coordinates Network (GCN)

Quick Look Analysis System

Automated, all the ISGR and JEMX data are

checked for bright new transients, or significantly variable sources

If confirmed, IAU Circ. will be issued Sensitivity ~ 50 mCrab QLA available a few hours (processing time)

after the data acquisition

Status of the instruments

JEMX radiation damage

Several anodes were lost High voltage reduced Bombardment of heavy ions? Only one is operation, the other spare

The first SPI annealing successful Higher background than expected?

Background characteristics being studied

Cyg X-1 images

SPI JEMX mosaic ISGR

Cyg X-1 energy spectra

Spectral shape

agrees with XTE reasonably well

Normalization does

not match yet

Crab pulsation (with ISGRI)

Time resolution ~60µsec

Gamma-ray bursts

SPI image and spectrum Of GRB030227 GRB021125 by SPI ACS

SPI raw spectrum (particle events)

Galactic Plane Scan (Cen region with ISGR)

New sources

IGRJ16318-4848

Detected in the ASCA archives! large absorption Extremely strong Fe line

For potential users…

AO2 will be announced in med/late 2003 Archives will start early 2004

All the data will be public

User supports from ISDC and INTEGRAL

GOF