The MAGIC TelescopeRazmick Mirzoyan Max-Planck-Institute for PhysicsMunich, GermanyEPS (July 17th-23rd 2003)Aachen, Germany

OutlineThe MAGIC CollaborationAiming for low threshold Physiscs goalsThe TelescopeDesign overviewMAGIC Key elements for low threshold Status of commissioning of the telescope elementsPlans & Conclusions

The MAGIC projectFirst presentation in 95 at the ICRC, Rome, (Bradbury et al)Approval of funding only late 2000Start of construction in 2001Now commissioningInnauguration October 10th

The MAGIC Collaboration

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 ZurichMajor Atmospheric Gamma-Ray Imaging Cherenkov TelescopeMAGIC is an international collaboration building a 17 m Cherenkov Telescope for the observation of HE cosmic rays.Main aim: to detect ray sources in the unexplored energy range: 30 (10)-> 250 GeVMAGIC 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!!!

The unexplored spectrum gapSatellites give a nice crowded picture of energies up to 10 GeV.Ground-based experiments show very few sources with energies > ~300 GeV.Effective area 104 m2

The MAGIC PHYSICS GoalsAGNsSNRsCold Dark MatterPulsarsGRBsTests on Quantum Gravity effectsCosmological g ray horizon

Absorption of extragalactic - raysAny that crosses cosmological distances through the universe interacts with the EBLAttenuated flux function of g-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 ISMMAGICBy measuring the cutoffs in the spectra of AGNs, MAGIC can help in determining the IR backgroundEBL

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 DepthThe 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

EBL absorptionMkn 501 (z=0.034)The absorption effect seen at TeV energies on a nearby blazarsH1426+428 (z=0.129)

GRH PredictionsTheoretical predictionsGRH prediction for several EBLGRH prediction for several MBL

MAGIC Expected sourcesMAGIC 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 sourcesFrom 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

PulsarsWhere do g-rays come from? Outer gap or polar cap?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)

Gamma Ray BurstsMechanism not yet fully resolved.MAGIC take advantage:Huge collection areaFast repositioning.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/yearMAGIC is designed to observe the prompt emission of a GRB!

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

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 Eg = mcg-line Eg = mc-mZ2 /mcg-flux predictions from c annihilations

Halo Dark Matter ProfilesIn our galaxy

ModelabgRo(kpc)a(kpc)Ra(Msun/pc3)R0(GeV/cm3)NFW 2d1318.021.80.0061590.34NFW 4d1318.05.2360.11010.43C-R & Moore1.501.58.533.20.001600.40D&B 2f11.81.88.01.00.41790.31NFW h1218.53.40.40.40

Photons Fluxg-ray flux ~ r2 search for DM clumps g-line signatures are negligible if gaugino fraction is highg-continuum dominates g-ray flux Galactic centre disfavoured (high g-diffuse) Globular clusters; dwarf spheroid galaxies100 hours obs. TimeAeff = 104 m2Eth=50 GeVMclump = 108 MA. Tasitsiomi, A. Olinto PhRevD 66, (2002)

Test of invariance of speed of lightQuantum Gravity models predict energy dispersion of c.Non trivial dispersion relation where EQG appears! (1016-1019)Photon delay depending on energy over distance

Given the huge sensitivity, MAGIC can observe fast transient phenomena like GRB and/or flare of AGN.10 s delayLorenz Invariance Deformation

Key elements of the MAGIC telescope577 pixels enhanced QE, 3.9 deg FOV camera + advanced calibration system2-level advanced trigger systemAnalog optical signal transport Light weight carbon fiber frame17 m diameter reflecting surface (240 m2 )Active mirror control

The frameThe 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. 2001. The assembly of the frame took only one month

The reflectorTessellated surface:~950 mirror elements 49.5 x 49.5 cm2 (~240 m2)All-aluminium, quartz coated, diamond milled, internal heating>85% reflectivity in 300-650nmThe overall reflector shape is parabolic (f/1), isochronous, to maintain the time structure of Cherenkov light flashes in the camera planeBetter light of night sky rejection (less pile-up)

mirror assemblyCabling of the mirror internal heatingAdjustment legs screwed on the mirror2 mirrors mounted on a panel

Optical alignment4 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

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 alignment of the mirrorsThe alignment of the first 103 mirrors in the telescope structure has been done by using a 20 W light source at a distance of 920mThe camera plane was moved 29 cm backward to focus the lamp light103 spots before and after the alignment~1 pixel

The alignment of the mirrors

The cameraTwo sections:Inner part: 0.100 PMTsOuter part: 0.200 PMTs Plate of Winston cones Active camera area 98 % includes 577 PMTs

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

Each PM is connected to an ultrafast low-noise transimpedance preamp.

6-dynode HV system zener stabilized with an active load240 m2 -> 312 m2 !!!

The camera statusThe temperature inside is controlled by a water cooling system with temperature/humidity sensors.

The camera was completed in summer 2002, after extensive tests and characterization

installed in November 2002

commissioned March 2003 after the winter break.

First starlight using DC current readout was recorded on March 8th.

The readoutCherenkov light pulses from air showers are typically ~ a few ns longPixel signals transported 162 m over optical fibres:No signal dispersionCable weight, optically decoupled, noise inmune.Sampling using 300 MHz-1GHz FlashADCs: g/h discrimination through signal shapeNoise reductionEvent buffering, telescope system synchronization...

TriggerTwo level trigger systemThe 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 (50-150 ns), and can perform a global sophisticated pattern recognition

Trigger- 44 GeVTrigger displayL2 pattern recognitionOff-lineOn-line

Trigger statusThe trigger has been commissioned since:Dec. 2002 (LT1)March 2003 (LT2)

The Data Acquisition SystemNeeds: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:Multiprocessor threaded system.PCI FPGA based readout card & RAID0 disks system.

MAGIC first light

MAGIC first light

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 With the engines at 70% of full power, the telescope was able to move of 180 in both axes in less than 30s

Future Plans August-September -> finishing installation of mirrors and electronics

September -> move to new counting house

October 10th Inaguration

Winter 2003-2004: start regular observation

Counting house

Conclusions 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

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

Parlero telescopio MAGIC come esempio di ground based experiment per la gamma-astronomia. Da quando fu osservata la prima sorgente nel 1989 (wipple) i Ttelescopi cherenkov hanno raffinato tecnologie e metodologie. Ora gli IACT sono un maturo strumento di misura e osservazione per lastronomia gamma delle alte energieSiamo giunti alla realizzazione di telescopi cherenkov di seconda generazione. Magic tra questi sara quello con la piu bassa soglia in energiaEsistono altri progetti di esperimento ground based non imaging cherenkov telescopes come solar array (celeste) o rivelatori di particelle in alta quota (ARGO) ma, almenno finora, non hanno dimostrato di avere un ottimale strategia di reiezione del fondo.

M. Mariotti Padova 30-01-2003Nella prima parte del talk illustrero la tecnica IACT riassumendo le pricipali peculiuaritDi seguito parlero del telescopio MAGIC, della collaborazione e dello stato di avanzamento della realizzazione dello strumentoPassero dunque ad illustrare gli obiettivi sceintifici di MAGICInfine le conclusioniM. Mariotti Padova 30-01-2003Il mio talk vertir sul telescopio magic come esempio di ground based sxperiment di seconda generazione

M. Mariotti Padova 30-01-2003Il mio talk vertir sul telescopio magic come esempio di ground based sxperiment di seconda generazione

M. Mariotti Padova 30-01-2003Something must happen in the gap, and its interesting enough to have an instrument to measure in it. Also to confirm some of the EGRET catalogue sources at higher energies.And also to cross check the energy calibration and measurements between satellites and ground based experiments.M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003M. Mariotti Padova 30-01-2003