First Results from MAGICthe Major Atmospheric Gamma-ray Imaging Cerenkov telescope

M.V. FonsecaUniversidad Complutense de Madrid

for the MAGIC Collaboration

JENAM 2004

EGRET- 100 MeV < Eγ < 10 GeV- A ~ 0.15 m2

> 270 sources (170 unidentified)

First Generation IACTs- Eγ > 300 GeV- A ~ 40000 m2

~ 18 sources

Something must happen inThe unknown energy range

10 GeV < Eγ < 300 GeV

The Gamma Ray Universe

Space detectors (GLAST 2007)Large field of viewSmall collection area (~1 m2)Energy sensitivity up to ~100 GeV

Ground detectors (ECO1000, MAGIC)Small field of viewLarge collection area (~104-105m2)Energy sensitivity from ~10 GeV

Large Cherenkov TelescopeOptimised for:

- low threshold: Eγ < 30 GeV - fast repositioning: tR < 30 s.

Many new technological elements

Cosmic Ray Detection Approaches

EnergyThresholdDown to30 GeV

A-Resolution: 0.2° @ 30 GeVdown to 0.1° > 100 GeV

E-Resolution: 30% @ 30 GeVdown to 15% > 100 GeV

3C2793C273

The “Big” Four

CANGAROO III(Australia & Japan)

Spring 20044 telescopes 10 meters Ø

Woomera, Australia

Windhoek, NamibiaHESS

(Germany & France)Summer 2002

4 ( 16) telescopes10 meters Ø

Roque delos Muchachos, Canary Islands

MAGICMAGIC(Germany, Italy & Spain)(Germany, Italy & Spain)

Winter 2002Winter 20021 telescope 17 meters Ø1 telescope 17 meters Ø

Montosa Canyon,Arizona

VERITAS(USA & England)

2005?7 telescopes10 meters Ø

Dark MatterDark Matter

PulsarsPulsars

GRBsGRBs

Quantum Gravity Quantum Gravity effectseffects

γγ--Ray HorizonRay Horizon

The MAGIC Physics Topics

SNRsSNRsAGNsAGNs

Diffuse Diffuse γγBckgrdBckgrd

Active Galactic Nuclei• Highest variability in

X-ray and γ rays• Multiwavelenght

campaigns necessary for source physics

• Closest to supermassive BH at Very High Energies

NGC 4261

Pulsars: Pulsar in Crab nebula• Rotating neutron star • Pulsed emission cutoff

10-50 GeV• Outer gap/

polar cap model ?• Continous TeV radiation

from shockfront

optical X-rayinfrared

radio

E.de Oña,next talk& R.Reyes poster 1.9

The Gamma Ray Horizon• High energy γ photons interact with γ of

the cosmic FIR to UV background by:

γHE γBKG e+e-

Attenuation• Cutoff in source spectrum

Knowledge of gamma ray horizon:Limits on cosmological parameters Cosmic star formation history

Lack of measurements

Cosmic Background light

• Origin of GRBs : Galactic or Cosmological

• Theoretical Emission Models:- Standard fireball, Internal & External Shock

• Multiwavelength study

• GeV studies possible if:– fast repositioning ~10 s– low E threshold ~30 GeV

Pulse Duration

“short”

“long”

Gamma Ray BurstsUniformity

10 s

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Mean Repositioning Time ~ 20 s

Point ANY place in the sky in ~30 s

What do we need to study GRBs? Telescope Fast Movement

~100 Physicists17 Institutes11 Countries

MPI Munich, GermanyU. Würzburg, Germany

U. Von Humboldt, Berlín, Germany

IFAE Barcelona, SpainUAB Barcelona, Spain

UCM Madrid, Spain

U. Padova/INFN Padova, ItalyU. Siena/INFN Pisa, Italy

U.Udine/INFN Trieste, Italy

ETH, Zurich, Switzerland

Crimean Observatory, UkraineU.C. Davis, U.S.A.

U. Lodz, PolandINR Moscow, Russia

U. Potshefstroom, South AfricaTuorla Observatory, Finland

Yerevan Phys. Institute, ArmeniaLa Palma, Canary Islands, Spain

THE MAGIC COLLABORATION

TNG

MAGIC

NOTING

Canary Islands

La Palma

The Site: Roque de Los Muchachos

The Site:The Site: Roque Roque de Los de Los MuchachosMuchachos

Control HouseControl House

MAGIC TelescopeMAGIC Telescope

HEGRAHEGRA--CTsCTs

EnergyThreshold

Ω - Pixel Solid Angleτ - Integration time

A - Mirror Areaε - Quantum Efficiency

Lowering the Energy Threshold

ετφ

AEth

Ω∝

Energy Threshold Mirror Area17 m diameter240 m2 diamond milled Al85%-90% reflectivityBuilt by MERO

ετφ

AEth

Ω∝

Lowering the Energy Threshold

Energy Threshold Pixel Solid Angle

EMI 9116A, 9117ARb-bialkali photocathode

Borosilicate hemispherical window

577 PMTs

Lowering the Energy Threshold

1”

2”

ετφ

AEth

Ω∝

Energy Threshold Quantum Efficiency

Lacquer

PTP+B-72+Dichloromethane

1. Increase γ path length

2. Light collector to cross twice the photocathode

∆QE ~ +30% XX

Lowering the Energy Threshold

ετφ

AEth

Ω∝

Lowering the Energy Threshold

Integration timeEnergy Threshold

Flash ADC @ 330 MHz, 8 bit

High Gain

High/Low gain (x5)

Dynamic range: 2000 (high/low gain)DAQ: Continuous ~20 Mbytes/sec ~1% deadtime @ 1 kHzInternal FIFO for 150 000 events (>20 kHz) Gamma Ray Bursts

Lowering the Energy Threshold

ετφ

AEth

Ω∝

DiscriminatorsDiscriminators

Level 1Level 1

# of photoelectrons

tight time coincidence

Level 2Level 2advanced pattern

recognition

The Trigger Architecture

A) Optimize focus on lamp (920 m)B) Memorize panel & laser positions

PSF

Laserpointers

Tracking of Jupiter

With AMC (positions from tables)

Without AMC

focusseddefocussed

Increasing zenith angle

Active Mirror Control

Muon rings

Real muon event

Muon rings can be used for calibration and flat-fieldingImages are determined by geometry onlyGood correlation between arc length and SIZEMeasure the charge in ring calculate conversion factorsUsed for calibration (25% agreement with LED pulser)

Image description by Hillas parametersWidth, LengthConcentrationSizeAlpha

Signal discrimination based on cuts of these parameters

γ showers point to source Alpha <10°

Analysis Technique

See M.Lopez et al. (poster 3.56)

Preliminary results: Crab

Excess = 287 events

Background = 303 events

Crab nebula (galactic SNR)Steady Gamma emission (standard candle): useful for calibration Very first look: ~50 minutes observation time detection !~ 8.0 events/minute after simple cuts

Significance ~ 10 σSignificance ~ 10 σ

Preliminary results: Mrk 421

Excess = 1307 events

Background = 565 events

Significance ~ 27 σSignificance ~ 27 σ

Mrk 421 (BL Lac, z=0.031) was flaring in FebruaryObservation time ~100 minutes27 sigma significance after simple cuts

MAGIC Milestones2000-2003 Construction of the telescope

Dec 2001 Dec 2001 -- FrameFrame 2002 2002 -- FrameFrame

2002 2002 -- CameraCamera

20032003

Nov 2002 Nov 2002 -- Trigger/DAQTrigger/DAQ

MAGIC Milestones

29 May 2003 First cosmics observed

2000-2003 Construction of the telescope

MAGIC Milestones

10 Oct 2003 Inauguration29 May 2003 First cosmics observed

2000-2003 Construction of the telescope

15 Feb 2004 First γ-ray source detections

MAGIC Milestones

10 Oct 2003 Inauguration29 May 2003 First cosmics observed

2000-2003 Construction of the telescope

MAGICMAGIC--II II (17 m)(17 m)MAGICMAGIC--I I (17 m)(17 m)

DesignDesign StudyStudy forfor ECOECO--1000 (35 m)1000 (35 m)a 34m a 34m telescoptelescopeeastroastro--phph/0403180/0403180

Build a second telescope⇒ Same mechanical structure⇒ Test bench for technical developments

Future Prospects and Developments

Conclusions

MAGIC MAGIC isis out out there forthere for real!real!

MAGIC MAGIC willwill explore explore the subthe sub--100 100 GeV window thanks to the many innovations GeV window thanks to the many innovations that have been introducedthat have been introduced

Many people have contributedMany people have contributed ((many studentsmany students…) …)

MAGIC has MAGIC has detected the first sourcesdetected the first sources ((CrabCrab,Mrk421) ,Mrk421) just just -- 6 6 months after the inauguration months after the inauguration -- onlyonly 3 1/2 3 1/2 years after initial funds were raisedyears after initial funds were raised

Lots of work still toLots of work still to be done! (be done! (calibrationscalibrations, “, “Low ELow Ethth”, …)”, …)

EnterEnter normal normal operation modeoperation mode in in OctoberOctober 20042004

MAGIC MAGIC isis a a discovery telescopediscovery telescopeAim at the detection of many new sourcesAim at the detection of many new sources !!

FIN