The MAGIC Telescope Razmick Mirzoyan Max-Planck-Institute for Physics Max-Planck-Institute for Physics Munich, Germany EPS (July 17 th -23 rd 2003) Aachen, Germany

, R.Mirzoyan, MPI Munich Outline The MAGIC Collaboration The MAGIC Collaboration Aiming for low threshold Aiming for low threshold Physiscs goals Physiscs goals The Telescope The Telescope Design overview Design overview MAGIC Key elements for low threshold MAGIC Key elements for low threshold Status of commissioning of the telescope elements Status of commissioning of the telescope elements Plans & Conclusions Plans & Conclusions

, R.Mirzoyan, MPI Munich The MAGIC project First presentation in 95 at the ICRC, Rome, (Bradbury et al) First presentation in 95 at the ICRC, Rome, (Bradbury et al) Approval of funding only late 2000 Approval of funding only late 2000 Start of construction in 2001 Start of construction in 2001 Now commissioning Now commissioning Innauguration October 10th Innauguration October 10th

, R.Mirzoyan, MPI Munich Barcelona IFAE, Barcelona UAB, Crimean Observatory, U.C. Davis, U. Lodz, UCM Madrid, INR Moscow, MPI Munich, INFN/ U. Padua, INFN/ U. Siena U. Siegen, Tuorla Observatory, Yerevan Phys. Institute, INFN/U. Udine, U. Wuerzburg, ETH Zurich The MAGIC Collaboration Major Major Atmospheric Atmospheric Gamma-Ray Gamma-Ray Imaging Imaging Cherenkov Cherenkov Telescope n MAGIC is an international collaboration building a 17 m Cherenkov Telescope for the observation of HE cosmic  –rays. n Main aim: to detect  –ray sources in the unexplored energy range: 30 (10)-> 250 GeV n MAGIC was a challenging design to decrease the energy threshold, by pushing the technology in terms of mirror size, trigger, camera sensors and electronics. � MAGIC shall provide the lowest threshold ever obtained with a Cherenkov telescope!!!

, R.Mirzoyan, MPI Munich Satellites give a nice crowded picture of energies up to 10 GeV. Satellites give a nice crowded picture of energies up to 10 GeV. The unexplored spectrum gap Ground-based experiments show very few sources with energies > ~300 GeV. Ground-based experiments show very few sources with energies > ~300 GeV. Effective area << 1 m 2 Effective area > 10 4 m 2

, R.Mirzoyan, MPI Munich The MAGIC PHYSICS Goals The MAGIC PHYSICS Goals n AGNs n SNRs n Cold Dark Matter n Pulsars n GRBs n Tests on Quantum Gravity effects Cosmological  ray horizon Cosmological  ray horizon

, R.Mirzoyan, MPI Munich Any  that crosses cosmological distances through the universe interacts with the EBL Absorption of extragalactic  - rays Attenuated flux function of  -energy and redshift z. For the energy range of IACTs (10 GeV-10 TeV), the interaction takes place with the infrared (0.01 eV-3 eV, 100  m-0.4  m). Star formation, Radiation of stars, Absorption and reemission by ISM MAGIC By measuring the cutoffs in the spectra of AGNs, MAGIC can help in determining the IR background EBL

This produces a reduction factor e -  in the  ray flux. The GRH is defined as the “z” for the observed energy “E” that fulfils: Optical Depth The probability of being absorbed for HE gamma crossing the universe is the integration of the cross-section over the incident angle and along the path from its origin to the observation. Gamma Ray Horizon (GRH) i.e. a reduction 1/e of the flux of the extragalactic source. Optical Depth & GRH MAGIC phase I MAGIC phase II

Mkn 501 (z=0.034) EBL absorption The absorption effect seen at TeV energies on a nearby blazars H (z=0.129)

GRH Predictions Theoretical predictions GRH prediction for several EBLGRH prediction for several MBL

MAGIC Expected sources MAGIC is not operating yet, so it is still a mystery how many extragalactic sources is going to detect but one can use the EGRET catalogue to find some very provable candidates. Assuming the foreseen MAGIC characteristics and 50 hours of observation time for each of these candidates, we expect to be able to measure the GRH at different redshifts.

Measurements from 20 expected sources From the extrapolation of the EGRET catalogue data we expect to be able to measure the GRH for 20 extragalactic sources using 50 hours for each. The Energy cut-off could be due to the source itself. It could be unfolded if one gets several sources at the same redshift. So we selected among these 20 sources the ones that have several at the same redshift and we kept 7. We can use half of the sample to improve EBL knowledge; i.e. to reduce systematics

Pulsars Where do  -rays come from? Outer gap or polar cap? Where do  -rays come from? Outer gap or polar cap? n Many of the ~170 EGRET unidentified sources may be pulsars. 7  -ray pulsars seen by EGRET. Only upper limits from present IACTs (spectral cut-off) 7  -ray pulsars seen by EGRET. Only upper limits from present IACTs (spectral cut-off) 4-fold nn-logic

, R.Mirzoyan, MPI Munich Gamma Ray Bursts Mechanism not yet fully resolved. Mechanism not yet fully resolved. MAGIC take advantage: MAGIC take advantage: Huge collection area Huge collection area Fast repositioning. Fast repositioning. Low energy threshold Low energy threshold Under the assumption that it is possible to extrapolate the GRB energy spectrum in the GeV region, MAGIC can observe 2-3 GRB/year MAGIC is designed to observe the prompt emission of a GRB!

, R.Mirzoyan, MPI Munich Other Physics targets for MAGIC n Search for neutralino annihilation gamma-ray line (galactic center, neighboring galaxies, globular clusters) n Tests of possible Lorentz invariance deformation: search for delay of HE gamma rays in rapidly varying phenomena at large distances (AGN flares, GRBs)

DM halo model Cross section  mass  mass The non barionic Dark Matter Stable weakly interacting massive particles (WIMPS) are attractive Cold Dark Matter candidates. At one loop, neutralinos can annihilate to  continuum  -line E  = m   - line E  = m   m  2  m   -flux predictions from  annihilations

Halo Dark Matter Profiles Model R o (kpc) a(kpc) R a (M sun /pc 3 ) R 0 (GeV/cm 3 ) NFW 2d NFW 4d C-R & Moore D&B 2f NFW h In our galaxy

Photons Flux  -ray flux ~  2  search for DM clumps  - line signatures are negligible if gaugino fraction is high  - continuum dominates  -ray flux  Galactic centre disfavoured (high  - diffuse) 1 Globular clusters; dwarf spheroid galaxies Moore et al. clump M clump =10 5 solar masses E th 100 hours obs. Time A eff = 10 4 m 2 MAGIC will cover a fair part of all possible parameters space E th =50 GeV M clump = 10 8 M  A. Tasitsiomi, A. Olinto PhRevD 66, (2002)

Given the huge sensitivity, MAGIC can observe fast transient phenomena like GRB and/or flare of AGN. Test of invariance of speed of light Quantum Gravity models predict energy dispersion of c. Quantum Gravity models predict energy dispersion of c. Non trivial dispersion relation where E QG appears! ( ) Non trivial dispersion relation where E QG appears! ( ) Photon delay depending on energy over distance Photon delay depending on energy over distance 10 s delay Lorenz Invariance Deformation S.D. Biller et al. PhRev Let 83, 2108 (1999) E QG > 6  GeV

, R.Mirzoyan, MPI Munich Key elements of the MAGIC telescope 577 pixels enhanced QE, 3.9 deg FOV camera + advanced calibration system 577 pixels enhanced QE, 3.9 deg FOV camera + advanced calibration system 2-level advanced trigger system 2-level advanced trigger system Analog optical signal transport Analog optical signal transport Light weight carbon fiber frame Light weight carbon fiber frame Light weight carbon fiber frame Light weight carbon fiber frame 17 m diameter reflecting surface (240 m 2 ) 17 m diameter reflecting surface (240 m 2 ) Active mirror control Active mirror control

, R.Mirzoyan, MPI Munich The frame The 17m diameter f/1 telescope frame is a lightweight carbon fiber structure (tube and knot system) The 17m diameter f/1 telescope frame is a lightweight carbon fiber structure (tube and knot system) The foundation started in September 2001 and the telescope was completed in Dec The assembly of the frame took only one month The foundation started in September 2001 and the telescope was completed in Dec The assembly of the frame took only one month

, R.Mirzoyan, MPI Munich The reflector Tessellated surface: Tessellated surface: ~950 mirror elements ~950 mirror elements 49.5 x 49.5 cm 2 (~240 m 2 ) 49.5 x 49.5 cm 2 (~240 m 2 ) All-aluminium, quartz coated, diamond milled, internal heating All-aluminium, quartz coated, diamond milled, internal heating >85% reflectivity in nm >85% reflectivity in nm The overall reflector shape is parabolic (f/1), isochronous, to maintain the time structure of Cherenkov light flashes in the camera plane The overall reflector shape is parabolic (f/1), isochronous, to maintain the time structure of Cherenkov light flashes in the camera plane Better light of night sky rejection (less pile-up) Better light of night sky rejection (less pile-up)

mirror assembly mirror assembly Cabling of the mirror internal heating Adjustment legs screwed on the mirror 2 mirrors mounted on a panel

Optical alignment 4 mirrors spots after the pre-alignment close to the virtual center of the MAGIC camera Final spot of a panel after The precise alignment of the mirrors

, R.Mirzoyan, MPI Munich The Active Mirror Control The panels can be oriented during the telescope operation through an Active Mirror Control system (AMC) to correct for possible deformation of the telescope structure The panels can be oriented during the telescope operation through an Active Mirror Control system (AMC) to correct for possible deformation of the telescope structure

, R.Mirzoyan, MPI Munich The alignment of the mirrors The alignment of the first 103 mirrors in the telescope structure has been done by using a 20 W light source at a distance of 920m The alignment of the first 103 mirrors in the telescope structure has been done by using a 20 W light source at a distance of 920m The camera plane was moved 29 cm backward to focus the lamp light The camera plane was moved 29 cm backward to focus the lamp light 103 spots before and after the alignment ~1 pixel

, R.Mirzoyan, MPI Munich The alignment of the mirrors

, R.Mirzoyan, MPI Munich The camera Two sections: Two sections: Inner part: PMTs Inner part: PMTs Outer part: PMTs Outer part: PMTs Plate of Winston cones  Active camera area  98 % Plate of Winston cones  Active camera area  98 % n includes 577 PMTs

, R.Mirzoyan, MPI Munich The camera Pixels: The photocatode QE is enhanced up to 30 % and extended to UV by a special coating of PM surface with milky wavelength shifter The photocatode QE is enhanced up to 30 % and extended to UV by a special coating of PM surface with milky wavelength shifter Each PM is connected to an ultrafast low-noise transimpedance preamp.Each PM is connected to an ultrafast low-noise transimpedance preamp. 6-dynode HV system zener stabilized with an active load6-dynode HV system zener stabilized with an active load 240 m 2 -> 312 m 2 !!!

, R.Mirzoyan, MPI Munich The camera status The temperature inside is controlled by a water cooling system with temperature/humidity sensors.The temperature inside is controlled by a water cooling system with temperature/humidity sensors. The camera was completed in summer 2002, after extensive tests and characterizationThe camera was completed in summer 2002, after extensive tests and characterization installed in November 2002installed in November 2002 commissioned March 2003 after the winter break.commissioned March 2003 after the winter break. First starlight using DC current readout was recorded on March 8th.

, R.Mirzoyan, MPI Munich The readout Cherenkov light pulses from air showers are typically ~ a few ns long Pixel signals transported 162 m over optical fibres: Pixel signals transported 162 m over optical fibres: No signal dispersion No signal dispersion Cable weight, optically decoupled, noise inmune. Cable weight, optically decoupled, noise inmune. Sampling using 300 MHz- 1GHz FlashADCs: Sampling using 300 MHz- 1GHz FlashADCs:  /h discrimination through signal shape  /h discrimination through signal shape Noise reduction Noise reduction Event buffering, telescope system synchronization... Event buffering, telescope system synchronization...

, R.Mirzoyan, MPI Munich Trigger Two level trigger system The level 1 (L1) is a fast coincidence device (2-5 ns) with simple patterns (N-next-neighbour logic) on single trigger cells. Level 2 (L2) is slower ( ns), and can perform a global sophisticated pattern recognition Two level trigger system The level 1 (L1) is a fast coincidence device (2-5 ns) with simple patterns (N-next-neighbour logic) on single trigger cells. Level 2 (L2) is slower ( ns), and can perform a global sophisticated pattern recognition Discriminators L0 Discriminators L0 Set the minimum number of photoelectrons per pixel to be used in the trigger Level 2 L2 Level 2 L2 Perform an advanced pattern recognition to use topological constraint: pixel counting in a given region of the detector mask hot spots like bright stars rough image reconstruction, etc…. On-line event selection To FADC Level 1 L1 Level 1 L1 Make a tight time coincidence on simple pattern of compact images and enable L2

Trigger  - 44 GeV Trigger display L2 pattern recognition Off-line On-line On-line image analysis on the trigger event Off-line analysis

Trigger status L2T L1T The trigger has been commissioned since: Dec (LT1) March 2003 (LT2)

, R.Mirzoyan, MPI Munich The Data Acquisition System Needs: Needs: 577 PMT x 1 Byte x 30 samples x 1 kHz 577 PMT x 1 Byte x 30 samples x 1 kHz  ~ 20 MByte/s (x 11 hours )  ~ 800 GB/night (longest nights in December) Cheap PC based solution: Cheap PC based solution: Multiprocessor threaded system. Multiprocessor threaded system. PCI FPGA based readout card & RAID0 disks system. PCI FPGA based readout card & RAID0 disks system.

, R.Mirzoyan, MPI Munich MAGIC first light

, R.Mirzoyan, MPI Munich MAGIC first light

, R.Mirzoyan, MPI Munich MAGIC first light

GRB alert: early follow-up The light weight structure and the low inertia of the structure allows a fast slewing time in such a way that the telescope will be able to perform an early follow-up of a Gamma Ray Burst The light weight structure and the low inertia of the structure allows a fast slewing time in such a way that the telescope will be able to perform an early follow-up of a Gamma Ray Burst With the engines at 70% of full power, the telescope was able to move of 180º in both axes in less than 30s With the engines at 70% of full power, the telescope was able to move of 180º in both axes in less than 30s

, R.Mirzoyan, MPI Munich Future Plans August-September -> finishing installation of mirrors and electronics August-September -> finishing installation of mirrors and electronics September -> move to new counting house September -> move to new counting house October 10th Inaguration October 10th Inaguration Winter : start regular observation Winter : start regular observation

, R.Mirzoyan, MPI Munich Counting house

, R.Mirzoyan, MPI Munich Conclusions So far all the new technical and technological novelties implemented in MAGIC behave as expected So far all the new technical and technological novelties implemented in MAGIC behave as expected In the next few month we will make extensive tests of the apparatus with engineering and physics runs In the next few month we will make extensive tests of the apparatus with engineering and physics runs We are considering MAGIC as the first element of an international observatory to study the deep universe with high energy gamma rays. We are considering MAGIC as the first element of an international observatory to study the deep universe with high energy gamma rays. Our proposal is to transform the MAGIC site, Roque de los Muchachos, in the “European Cherenkov Observatory” ECO Our proposal is to transform the MAGIC site, Roque de los Muchachos, in the “European Cherenkov Observatory” ECO