1. 07 Feb, 2009Rencontres de Moriond 20091 TACTIC & MACE gamma-ray telescopes Kuldeep Yadav ( For HIGRO collaboration) Astrophysical Sciences Division Bhabha Atomic Research Centre Mumbai- 400 085, India

2. 07 Feb, 2009Rencontres de Moriond 20092 TACTIC telescope (TeV Atmospheric Cherenkov Telescope With Imaging Camera) Control room TACTIC console

3. 07 Feb, 2009Rencontres de Moriond 20093 TACTIC Parameters Location : Mt. Abu, Rajasthan (72.7dE,24.6dN, 1400m asl) Light collector : ~9.5 sq. meter Camera FoV : 5.9d x 5.9d (349 pixels) Trigger FoV : 3.4d x 3.4d Trigger Criteria : 3NCT (Fast RAM based) SPE threshold : 7pe Energy threshold : ~1 TeV Distributed 4-node DAS using RTOS Drive Control : SM based (120Ncm) Observations time : 1170 hr/year( Oct-June) NIM & CAMAC R.Koul et. al., Nucl. Instrum. and meth. A., 578(2007) 548

4. 07 Feb, 2009Rencontres de Moriond 20094 Multi-node Data Acquisition System Semaphore Manager CAMAC Driver LED Driver GAIN CONTROL HV DRIVER LED CAMAC SCALER G A I N C O N T R O L N O D E SCALER Test HV Test PCR CCR Q N X NODE #3 HV Q N X NODE # 1 C D C D A T A N O D E SHARED MEMORY CAMAC Driver Linux NODE # 4 --- Data Processing --- Display --- Data quality check --- Archiving Q N X NODE # 2 CDC DATA - EVENT - CALIBRATION - SKY-NOISE CAMAC CDC CAMAC TTG` INTERRUPT HANDLER - Master Process - Display Manager - Data Storage TCP - IP ACE Event Calibration Event ( From TTG ) LED Driver Chance Event Linux NODE # 4Linux NODE #5 --- Data Processing --- Display --- Data quality check --- Archiving Multi-node DA & CS of TACTIC

5. 07 Feb, 2009Rencontres de Moriond 20095 Mrk 501 observations 1997

6. 07 Feb, 2009Rencontres de Moriond 20096 Crab Nebula Observations (2003-04)

7. 07 Feb, 2009Rencontres de Moriond 20097

8. 07 Feb, 2009Rencontres de Moriond 20098 TACTIC observation of MrK 421 (2005-06)

9. 07 Feb, 2009Rencontres de Moriond 20099 TACTIC light curve of Mrk 421 (2005-06)

10. 07 Feb, 2009Rencontres de Moriond 200910 Crab & Mrk 421 concurrent Energy Spectra (2005-06) K.K.Yadav et. al., Astroparticle Physics, 27(2007) 447

11. 07 Feb, 2009Rencontres de Moriond 200911 On-source alpha plot of 1ES2344 + 514 (60 h data during 2004-05) S.V.Godambe et. al., J.Phys.G:Nucl.Part.Phys. 34(2007) 1683 I(≥1.5 TeV) ≤ 3.84 x 10 -12 ph cm -2 s -1

12. 07 Feb, 2009Rencontres de Moriond 200912 Mrk 501 observations (2006) 7.5 sigma in 69 h 2005 observation ~46h I(≥1 TeV) ≤ 4.62 x 10 -12 ph cm -2 s -1 2006 observation ~69h

13. 07 Feb, 2009Rencontres de Moriond 200913 Mrk 501 energy spectrum (2006) S.V.Godambe et. al., J.Phys.G:Nucl.Part.Phys. 34(2008) 065202 f0=1.66±0.52 x 10 -11 cm -2 s -1 TeV -1 ſ = 2.8 ± 0.27

14. 07 Feb, 2009Rencontres de Moriond 200914 H1426+428 observations (2004,06,07) ~150 h K.K.Yadav et. al., submitted to J.Phys.G:Nucl.Part.Phys.

15. 07 Feb, 2009Rencontres de Moriond 200915 TACTIC & ASM light curves of H1426

16. 07 Feb, 2009Rencontres de Moriond 200916 Project HIGRO an introduction A New Indian initiative in  - ray astronomy Project HIGRO ( Himalayan  - Ray Observatory) Collaborators --- IIA, TIFR and BARC ………………….. 7 Element HAGAR wavefront sampling telescope + 21m dia. Stereo MACE ( Major Atmospheric Cerenkov Experiment) Each telescope element will use a cluster of ~1408 PMTs with a pixel resolution of 0.1 0 ; FoV ~ 4 0 x 4 0. Aim : Study the sky in the unexplored energy range E γ > 20 GeV to bridge the gap between the space-based and the ground based detectors.

17. 07 Feb, 2009Rencontres de Moriond 200917 Hanle, Ladakh (32.7d N, 79d E, 4200m asl)

18. 07 Feb, 2009Rencontres de Moriond 200918 Observatory site 10kmphMed. Wind speed IIA Campus, HANLE Location 4200 m asl (~ 600 g cm -2 ) Altitude 32.7 0 N, 78.9 0 ELat. And Long 8 hrsLeh- Hanle travel 260 KmNearest town -24 0 C (at night) Min. Temp May - Oct Time for out door work -2 0 C (at night) Med. Temp. 30%Med. Rel. Humidity full yearAccessibility Site Characteristics 2m HCT Telescope site IIA Campus, Hanle 4200 m asl (~ 600 g cm -2 ) HAGAR (1/7) High altitude related difficulties

19. 07 Feb, 2009Rencontres de Moriond 200919 Advantages of setting up MACE at HANLE Reduction in threshold energy by a factor of ~ 2.5-3.5 at Hanle ( ~ 4200m asl ) compared to lower Altitudes sites like Gurushikhar ( ~1700m asl). Cloud free sky --- Spectroscopic Nights : ~260 nights / yr Photometric Nights : ~190 night /yr Year round sky coverage -- Quite a few important sources cannot be observed at Gurushikhar during June-Sept due to Monsoon. Concurrent observations with HAGAR telescope (>60GeV) & Coordinated multi-wavelength observations with the HCT at Hanle. Improvement in sensitivity because of being closer to shower maximum ( images become broader at higher altitudes).

20. 07 Feb, 2009Rencontres de Moriond 200920 Broad guide lines for designing the MACE telescope Lower the energy threshold to ~20GeV (Observation altitude, Large light collection area, small coin. gate width, appropriate pixel size, CPCs, Intelligent trigger generation scheme) Employ GHz signal processing using Analog Ring Sampler Install MACE in the close vicinity of the HAGAR array Improve detection sensitivity by using coincident HAGAR data Use central pixel for used for optical monitoring of the source ---- photometric observations Fast repositioning of the telescope --- high energy tails of GRBs. Operate PMTs at a gain of ~20,000 --- ( use partially moon lit nights) Improve detection sensitivity – employ a stereo system in a phased manner

21. 07 Feb, 2009Rencontres de Moriond 200921. Increase in Cherenkov Photon density with altitude

22. 07 Feb, 2009Rencontres de Moriond 200922 Major mechanical sub-systems of the telescope Telescope structure material -- Steel – SA-333 Gr 6 (suitable for low temp. applications) Mirror basket structure Aluminum Honey comb panels for mounting mirror facets Active Miror control (AMC) alignment system Camera vessel for housing focal plane instrumentation Drive control system ( DC servo motors with 17 bit encoders) Track and wheel design concept for azimuth motion (27 m dia) Camera handling and maintenance structure Total weight ~ 150 MT Overall height of the telescope ~ 45m Operational/ Survival wind speed ~ 45 km/h // 150 km/h Operating temp. ~ -30 0 C to 05 0 C ( Winter) ~ 05 0 C to 30 0 C (Summer) Critical design issues Load (Self-weight, 1200 kg camera, Wind load) Deflection, Shadow region, Transportation

23. 07 Feb, 2009Rencontres de Moriond 200923 MACE telescope --- Light collector design Diameter (area)2100 cm ( tessellated design – 356 panels) – 337 m 2 Focal distance 2500 ( ~ f/1.2 design) Individual mirror facets Diamond Milled Al 4 x (050cm X 050cm ) 1 x (100cm X050cm ) Configuration Paraboloid with graded focal length panels

24. 07 Feb, 2009Rencontres de Moriond 200924 Expected PSF of the light collector Plate scale : 43.6mm =0.1 0

25. 07 Feb, 2009Rencontres de Moriond 200925 Imaging camera specifications: Total pixels 1408 Pixels in trigger region 564 Total FoV ~ 4 0 x 4 0 Trigger FoV ~ 2.4 0 x 2. 4 0 Pixel size (at cpc) 45 mm photo cathode dia 22/29 mm Imaging camera Vessel Size : 2m x 2m x 2.5m Mass : 1200 kg Requirement of a good camera design --- pixel size and camera FoV  Pixel size depends upon the differences in the characteristic size of gamma-ray and hadron generated Cerenkov images.

26. 07 Feb, 2009Rencontres de Moriond 200926 Signal Processing Hardware 16 channel module GHz Sampling Integrated Camera (all signal processing instrumentation housed within the camera structure of 2mx2mx1.2m size) Temperature control of the Camera during operation and standby condition.

27. 07 Feb, 2009Rencontres de Moriond 200927 Monte Carlo simulation studies CORSIKA air shower simulation code Energy range -- 1 - 1000 GeV for gamma-rays & e; 10 - 10000 GeV for p & alpha Observatory altitude : 4200 m asl ( Hanle) LONS background : 3.0 x 10 12 photons m -2 s -1 sr -1 No. of showers generated : 8 x 10 6 each for γ, p, α & e Zenith angle : Vertical incidence Impact parameter : 0-400 m for gamma -rays, e & p ; 0-500 m for alpha Mirror reflectivity, CPC collection efficiency, : Taken into account Atmospheric extinction Trigger FoV : 2.4 0 x 2.4 0 Single pixel threshold ~ 4 pe Trigger generation logic : NNQ

28. 07 Feb, 2009Rencontres de Moriond 200928 Monte Carlo simulation studies– Effective collection area

29. 07 Feb, 2009Rencontres de Moriond 200929 Monte Carlo simulation studies – Threshold energy estimates

30. 07 Feb, 2009Rencontres de Moriond 200930 Preliminary calculations using Hillas parameters Standard image cleaning procedure picture threshold =4.4pe & Boundary threshold= 2.2pe. Hillas parameters ( Length, Width, Frac2, Distance, Alpha ) ( Dynamic supercuts with Alpha<8 0. ) Detection sensitivity for Crab Nebula @ 5σ significance T min ~ 13 mins ( @ Size> 530pe -- Eγ > 200 GeV) T min ~ 43 mins ( @ Size>50 pe -- Eγ > 55 GeV ) MACE sensitivity is still preliminary. We still have a long way to go to improve this figure !!

31. 07 Feb, 2009Rencontres de Moriond 200931 Implementation status Funding for 1 MACE element already approved (~ 40 crores ) $ 8 M Telescope mechanical design (~ DDR is completed ) First Light --- 2010 (Single MACE element ) Agenda for ongoing work Prototype 256 pixel camera with ARS –based instrumentation being developed at BARC Camera design optimization (~ FOV and Pixel size --- arrive at the most optimum configuration) Use of WLS dyes for improving the QE of PMTs Include PMT temporal response in MC simulations. Use pulse profile information also for improving γ /h segregation Achieve T min ~ 100 GeV using conventional analysis and simultaneously use alternative γ /h segregation methodologies for improving the sensitivity @ E γ < 100 GeV Simulation for stereo MACE Repeat simulations at different zenith angles & also at lower altitude (~1600 m) for quantifying the quantum of sensitivity improvement at higher altitude.

32. 07 Feb, 2009Rencontres de Moriond 200932. THANK YOU