Indian Astronomy Satellite Mission (ASTROSAT) National Institutions 1.ISRO, Bangalore 2.TIFR, Mumbai 3.IIA, Bangalore 4.RRI, Bangalore 5.PRL, Ahmedabad International Institutions 1.University of Leicester, UK 2. Canadian Space Research Centre, Canada Kallol Mukerjee Department of Astronomy and Astrophysics Tata Institute of Fundamental Research (TIFR), Mumbai, INDIA

ASTROSAT The first fully dedicated multi-wavelength Indian astronomy mission To be launched from India in 2008 using PSLV at 600 km near equator at low inclination angle <10 degrees Cover wide X-ray energy band keV along with UV and Optical wave bands Timing, Spectroscopy, Imaging and long term monitoring Every instrument is configured in its own inherent features to achieve scientific requirements in specified wave band ASTROSAT is conceived with the prime objective is to do front ranking research utilising multi-wave length capabilities

ASTROSAT Instrument Configuration Soft X-ray Telescope (SXT) Cadmium Zinc Telluride Imager (CZT) Large Area X-ray Proportional Counter (LAXPC) Scanning X-ray Sky monitor (SSM) (UVIT) UV Imaging Telescope (UVIT)

Soft X-ray Telescope (SXT) CCD-22 based Focal Plane Camera

SXT Characteristics Telescope Focal Length2.0 metres Telescope MirrorsConical shells Telescope PSF3 - 4 arcmin Field of view41.3 x 41.3 arcmin DetectorMAT CCD-22 (cooled to -80 deg C) Detector Format600 x 600 pixels Pixel Scale4.13 arcsec/pixel Detector Readout ModesPhoton counting, Imaging & Timing Energy Range0.3 – 8.0 keV Effective Area keV keV Sensitivity 10µ Crab (5  ; 10 4 s) Position Accuracy30 arcsecs

Large Area X-ray Proportional Counter (LAXPC)

LAXPC Characteristics Collimator field of view1 0 x 1 0 for all the LAXPCs Collimator height45 cm for FOV collimator Material for the Collimator50µ Sn + 25µ Cu + 100µ Al Absorber Gas90 % Xenon + 10 % Methane Gas Pressure~ Two atmosphere (1670 torr) Detector Window50 (or 25) µ thick Mylar coated one side with 500 Å thick Aluminium Energy range3-80 keV Average detection efficiency100% (E < 20 keV) ~ 50 % in keV Time resolution10 ms (10µ sec for event mode) Sensitivity14000 counts per sec per Crab Unit

CZT Imager Assembly Radiator Plate X connector CAM with Holder Collimator CZT Top Housing CZT Bottom Housing Mounting/Interface Lug Heat Pipe Radiator Holding Bracket Alpha Box

CZT Characteristics Area1024 cm 2 Pixels16384 Pixel size2.5 mm X 2.5 mm (5 mm thick) Read-outASIC based (128 chips of 128 channels) Imaging methodCoded Aperture Mask (CAM) Field of View17 o X 17 o (CAM) > 100 keV 6 o X 6 o (10 – 100 keV) Angular resolution8’ (21’ geometric) Energy resolution 60 keV Energy range10 – 100 keV Up to 1 MeV (Photometric) Sensitivity 0.5 mCrab (5  ; 10 4 s)

 Measure periodicities and their evolution including Pulsations, QPOs, Binary periods etc. (Studies of QPOs above 20 keV is relatively unexplored field).  Timing and spectral evolution of X-ray bursts, flares and other sporadic variability.  Studies of X-ray Transients and their temporal and Spectral characteristics.  Long and Short term variability in AGNs. Principal Science Objectives of Astrosat X-ray instruments 1. Timing studies of X-ray Binaries 2.Studies of continuum X-ray emission over a broad band of 3-80 keV. X-ray Binaries, Supernova remnants (SNRs), CVs, Stellar Coronae, AGNs etc.

3.Detection of non-thermal components in the X-ray spectra of SNRs and Clusters of Galaxies By accurate spectral measurements in 3 – 80 keV band in combination with Simultaneous measurements from SXT in 0.3 – 8 keV region to understand the acceleration processes and origin of cosmic rays in the case of SNRs. 4. Measuring magnetic fields of neutron stars By detection and studies of cyclotron lines, most of which lie in 10 – 60 keV region in the spectra of X-ray pulsars. 5. Correlated time variations of intensity In 3-80 keV band with those in the visible, UV and soft X-ray (0.3-8 keV) bands to investigate the origin and mechanism of emission of radiation in different wave bands. Principal Science Objectives of Astrosat X-ray instruments (continued…)

Scientific Objectives of SSM  To detect and locate new transients Long period Be binaries, X-ray novae, etc.  Alert observers Point Astrosat, carry out optical identification and obtain system parameters like mass function, binary period, mass of the compact object etc..  Study X-ray binary sources over a large dynamic range L – to erg/s; dM/dt.  Source states Low hard state, High soft state, Intermediate, very high etc.  Super orbital period in HMXBs Precession period of disc/neutron star  Long term cycles and Irregular variations in LMXBs Mass transfer instabilities?  Pulsar studies Spin up/down phases of pulsars.

Ultraviolet Imaging Telescope (UVIT) Two Telescopes each of 38 cm Aperture (Twin Richey Chretian 2 mirror system) Three channels simultaneously Far UV (130 nm – 180 nm), Near UV (180 nm – 300 nm) and visible (350 nm – 600 nm) Photon counting + CCD based UV and optical detectors Filters: FUV: 135 nm, CIV (155 nm), 165 nm; NUV: CIII (190.9 nm), 225 nm, CII (235 nm), O II (247 nm), 255 nm, 285 nm Sensitivity = 21 mag (in 1000 seconds) Field of view = 30 arcmins (>50 times that of HST) Angular resolution = 1.8 arcsec (2-3 times better than GALEX) Time resolution = 1 s

Scientific Objectives with UVIT Deep Surveys: UV sky survey, Detection of galaxies at z ~ 2, Faint quasars and AGNs. Lyman-  Surveys: Nearby galaxies & clusters of galaxies. Galaxies in UV: Evolution of stellar populations, OB stars, Dust properties, morphology. Hot Stars in the local group of galaxies : global studies of young population In the Milky Way: Studies of populations of sub-classes of White Dwarfs, WDs in the globular clusters High Mass Stars and luminous blue variables – distance calibrators Interstellar Matter Probes Stellar Solar Connection (cool stars; Rotation, magnetic activity, UV flares) Cataclysmic Variables and X-ray Binaries

ASTROSAT: Key Scientific Objectives 1.SIMULTANEOUS COVERAGE (UV, Soft X-rays and Hard X-rays): Environment of BLACK-HOLES and other ACCRETION POWERED sources. 2.WIDE BAND X-ray SPECTROSCOPY: Continuum + line emission; Separation of thermal and non-thermal components. 3.TIMING: Pulsars, QPOs etc. 4.TRANSIENT SOURCES 5.UV SURVEY, Young stellar Populations