Xray transients with Astrosat A R Rao Tata

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X-ray transients with Astrosat A R Rao Tata Institute of Fundamental Research, India (arrao@tifr.

X-ray transients with Astrosat A R Rao Tata Institute of Fundamental Research, India (arrao@tifr. res. in) Workshop on Transients 16 Feb 2015

Plan �Astrosat - General Introduction - X-ray instruments (CZT-Imager – Polarisation) �Transients - Long

Plan �Astrosat - General Introduction - X-ray instruments (CZT-Imager – Polarisation) �Transients - Long period - X-ray transients - Fast transints �GRBs : Prompt Emission �Conclusions

ASTROSAT � IRS (Indian Remote Sensing) Class � Launch PSLV 29 from SHAR �

ASTROSAT � IRS (Indian Remote Sensing) Class � Launch PSLV 29 from SHAR � Altitude : 650 km; Inclination : 6 deg. � Mass 1550 kg. (780 kg. Payloads) � Power : 2200 watts � 200 Gb (210 Mb/sec) � Satellite Positioning System for orbit and time data � Payload pointing (3 ): 0. 05 degree � Slew rate : 0. 6 deg/sec � Launch: Third quarter of 2015 � Operational life > 5 years 3 Slide courtesy: K S Sarm

Astrosat Instruments 1. LAXPC: Large Area X-ray Proportional Counters; Aeff ≈ 6000 cm 2;

Astrosat Instruments 1. LAXPC: Large Area X-ray Proportional Counters; Aeff ≈ 6000 cm 2; FOV =10 X 10; 3 -80 ke. V; E/ΔE ≈ 5 to 12. 2. CZTI: Cadmium-Zinc-Telluride Imager with Coded Aperture Mask (CAM); Aeff = 500 cm 2; FOV = 60 X 60; 10 – 100 ke. V; E/ΔE ≈ 20 to 30. 3. SXT : Soft X-ray Telescope using conical-foil mirrors A eff ≈ 200 cm 2 ; FOV = 0. 50; (~3‘ res); 0. 3 -8 ke. V; E/ΔE ≈ 30 4. SSM : Scanning Sky Monitor with 3 PSPCs and CAM; A eff ≈ 30 cm 2 (each); 2 -20 ke. V. 5. UVIT : Ultraviolet Imaging Telescope two telescopes each with 38 cm aperture; near-uv , far-uv and visible bands. 4

LAXPC: Large area Xenon-filled Proportional Counters Energy range : 3 – 80 ke. V

LAXPC: Large area Xenon-filled Proportional Counters Energy range : 3 – 80 ke. V Time Resolution: 10 sec Area Three identical xenon filled proportional counters. Multi layer and multi cell geometry with 60 anode cells and 28 anti cells : 6000 cm 2 (7980) E / E ~ 3 - 7 Xenon + methane mixture at a pressure 1500 mm of Hg. 50 micron thick aluminized Mylar window with a FOV of 1 ox 1 o 5 Slide courtesy: Ravi Manchand

6 Slide courtesy: Ravi Manchand

6 Slide courtesy: Ravi Manchand

Soft X-ray Telescope (SXT) Telescope Length: 2465 mm (Telescope + camera + baffle +

Soft X-ray Telescope (SXT) Telescope Length: 2465 mm (Telescope + camera + baffle + door) Top Envelope Diameter: 386 mm Focal Length: 2000 mm Epoxy Replicated Gold Mirrors on Al substrates in conical Approximation to Wolter I geometry. Radii of mirrors: 65 - 130 mm; Reflector Length: 100 mm Reflector thickness: 0. 2 mm (Al) + Epoxy (~50 microns) + gold (1400 Angstroms) No. of nested shells : 40 No. of reflectors: 320 (40 per quadrant) Detector : E 2 V CCD-22 (Frame-Store) 600 x 600 Field of view : 41. 3 x 41. 3 arcmin PSF: ~ 2 arcmins Sensitivity (expected): 15 Crab (0. 5 cps/m. Crab) 7 Slide courtesy: K P Singh

8 Slide courtesy: K P Sing

8 Slide courtesy: K P Sing

CCD: X-ray illumination CCD: Optical illumination Mn Kα, Kβ 145 e. V resn. 9

CCD: X-ray illumination CCD: Optical illumination Mn Kα, Kβ 145 e. V resn. 9 Slide courtesy: K P Sing

Scanning Sky Monitor (SSM) • 3 PSPC • Area 60 cm 2 (5 ke.

Scanning Sky Monitor (SSM) • 3 PSPC • Area 60 cm 2 (5 ke. V) • Ang res. : 2. 5 o & 12’ • Res 20%@ 6 ke. V 10

CZT-Imager. . . Size: 482 x 458 x 603 mm Heat pipes CFRP support

CZT-Imager. . . Size: 482 x 458 x 603 mm Heat pipes CFRP support Weight - 50 kg Power – 60 Watts Collimator: 6 x 6 Degree 17 x 17 Degree Handling brackets CAM Collimator Side joining plates CZT top hsg. Radiator Optical cube Alpha tag source CZT bottom hsg. 11

CZT-Imager characteristics Area 1024 cm 2 Pixels 16384 Pixel size 2. 4 mm X

CZT-Imager characteristics Area 1024 cm 2 Pixels 16384 Pixel size 2. 4 mm X 2. 4 mm (5 mm thick) Read-out ASIC based (128 chips of 128 channels) Imaging method Coded Aperture Mask (CAM) Field of View 17 X 17 deg 2 (uncollimated) 6 X 6 (10 – 100 ke. V) – CAM Angular resolution 8 arcmin Energy resolution 5% @ 100 ke. V Energy range 10 – 100 ke. V - Up to 1 Me. V (Photometric) Sensitivity 0. 5 m. Crab (5 sigma; 104 s) 12

Polarization: the new buzzword - Photo-electric effect. GEMS - Thomson scattering – Polix 4

Polarization: the new buzzword - Photo-electric effect. GEMS - Thomson scattering – Polix 4 – 30 ke. V - Compton scattering – Integral Cyg X-1 - CZT-I has Polarization Sensitivity in 100 – 200 ke. V CZTI Team (DB, VB, SVV)

Polarization Crab 3 sigma detection in < 1 day Next (%) 1: 2 3:

Polarization Crab 3 sigma detection in < 1 day Next (%) 1: 2 3: 4 4: 5 Obs 2. 4+0. 1 4. 3+0. 2 0. 8+0. 1 8. 0+2. 0 Monte Carlo 2. 43 4. 9 1. 0 10. 0

CZTI: capabilities: Polarization: 1 Crab in one day; Bright (~10 -6 erg cm-2) GRBs.

CZTI: capabilities: Polarization: 1 Crab in one day; Bright (~10 -6 erg cm-2) GRBs. 15 Vadawale et al. 2014

Sensitivity for Cyg X-1 & Crab Chattopadhyay et la. Exp Astr. 37, 555 Vadawale

Sensitivity for Cyg X-1 & Crab Chattopadhyay et la. Exp Astr. 37, 555 Vadawale et al. A&A, submitted

Astrosat: Special Features • Low Inclination • Continuous time-tagged individual photon data (LAXPC &

Astrosat: Special Features • Low Inclination • Continuous time-tagged individual photon data (LAXPC & CZTI) – a few tens of micro-second accuracy • Bright source observing capability of SXT • Facility to change/ adjust observation time of SSM pointing. • Hard X-ray (above ~ 80 ke. V) monitoring capability. 17

Transients �Months to years TDEs etc. SXT �Days to Months - blazars (SSM/SXT) -

Transients �Months to years TDEs etc. SXT �Days to Months - blazars (SSM/SXT) - X-ray transients in XRBs �Minutes to hours - XRBs – LAXPC survey �Seconds - GRBs

X-ray Transients: Key Science Topics Wideband X-ray spectroscopy Spectral-timing analysis Disk-Jet connection Long term

X-ray Transients: Key Science Topics Wideband X-ray spectroscopy Spectral-timing analysis Disk-Jet connection Long term soft/ hard variability Quasi Periodic Oscillations 19

Wide Band X-ray Spectroscop y with Astrosat LAXPC SXT CZT Zdziarski et al. 2005

Wide Band X-ray Spectroscop y with Astrosat LAXPC SXT CZT Zdziarski et al. 2005 • Overlapping energy ranges • Low background and simultaneous measurement • Wide dynamic range. 20

GRB: Observation Strategy � Select bright Swift/ Fermi GRBs. � Position information from PTF

GRB: Observation Strategy � Select bright Swift/ Fermi GRBs. � Position information from PTF for Fermi GRBs � Identify Astrosat/CZTI GRBs. � Identify `interesting’ bursts from prompt spectral analysis. � Have optical/ radio (GMRT) follow up. � Make a detailed comparison of the prompt spectro-polarimetric parameters with multiwavelength afterglow observations.

Conclusions �Astrosat is an observatory class satellite, scheduled to be launched this year. �All

Conclusions �Astrosat is an observatory class satellite, scheduled to be launched this year. �All sky monitoring by SSM and wide filed hard X -ray monitoring by CZTI will make Astrosat an useful instrument to study transients. �Wide band X-ray spectroscopy and polarization capabilities can be used for follow-up observations.