1. Introduction Data analyzed Analysis method Preliminary results
Nadia Tonello, Max-Planck-Insitut für Physik, München
First 1ES observations with the MAGIC telescope and comparison with Crab Nebula at 40 ZA
Introduction
Data analyzed
Analysis method
Preliminary results

2. Nadia Tonello, MPI Munich
What is 1ES ?
Elliptical galaxy
Active Galactic Nucleus
z = 0.047
RA =19h59m59.8s
Dec = +6508'54''
Observability from La Palma:
May-October 35-54 z.a.
1998: First  detection: Utah Seven Telescope Array
Weak source
Confirmed in 2002 by WHIPPLE and HEGRA
Most interesting aspect: orphan flare in June 2002.
Candidate source for south neutrino telescopes
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3. Nadia Tonello, MPI Munich
The MAGIC Telescope
Canary Island La Palma
2200 m asl
Largest Imaging
Air Cherenkov
Telescope
for -ray astronomy
17 m mirror dish
3.5 field of view
576 high-QE PMTs
Design optimized for:
low energy threshold E = 30 GeV
fast repositioning tR<30 sec
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4. Imaging Air Cherenkov Telescopes
Gamma
ray
Cherenkov light Image of particle shower in telescope camera
reconstruct:
arrival direction, energy
reject hadron background
~ 10 km
Particle
shower
~ 1o
Cherenkov light
~ 120 m
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5. Nadia Tonello, MPI Munich
Standard Analysis
gamma shower
Shower reconstruction
and background rejection based on image shape
analysis
raw image
cleaned image
Hillas parameters:
Length, width, distance,
alpha
hadron shower (background)
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6. Nadia Tonello, MPI Munich
MAGIC raw data
Source
Days
Obs. Time
ZA range
Azimuth
1ES
September 06, 07
October 07, 10,14,15,16,17
6 h 55 m
4.4 M events
min = 35
max = 47
min = -26
max = 2
Crab Nebula
September
13, 14, 15, 16,21,22,23
2 h 17 m
1.7 M events
max = 46
(selected)
min= 85
max = 94
Off data
September 8, 10, 11, 12, 13, 14, 16, 17
2 h 49 m
2.3 M events
Cuts optimized on Crab Nebula and applied to 1ES1959 and Off data
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7. Nadia Tonello, MPI Munich
Preliminary analysis
Extract pedestals from data
Image cleaning :
Pedestal RMS levels: 4 sigma, 2 sigma (5 rings)
Absolute number of photons: 40 ph, 25 ph
Image parameters distributions have been compared for the 3 data sets.
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8. Nadia Tonello, MPI Munich
Preliminary analysis
Random Forest
MC  noise tuned to september off data sample.
Hadrons randomly chosen from real on data (25 k events).
Parameters: Width, Length, Size, Dist, Conc,
logLength(logSize), logWidth(logSize), M3Long
Cut in MHadronness
chosen from Crab:
Maximum significance: had = 0.1
Maximum excess events: had = 0.5
Cuts applied to 1ES1959 without any further optimization.
Significance
Excess events
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9. Nadia Tonello, MPI Munich
Signal above 2000 ph.
Crab Nebula: Size >2000 ph
Significance: 26.4  Excess events: 529 ± 20
1ES : Size >2000 ph
Significance: 7.0  Excess events: 165
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10. Nadia Tonello, MPI Munich
Time analysis
Binning in about 2 h data
No substantial variation of activity
Days
Obs time
Significance
Excess
Rate
(phot/min)
September
6,7
121 min
3.6
42.8 ± 11.8
0.35 ± 0.09
October 7,10,15
110 min
4.0
49.5 ± 12.3
0.45 ±0.11
October 16, 17
137 min
5.0
64.0 ± 12.8
0.46 ± 0.09
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11. Nadia Tonello, MPI Munich
X-ray light curve
Activity not particularly high
5 - 7 Sept
7 -17 Oct
RXTE mission day
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12. Nadia Tonello, MPI Munich
Optical light curve
Quiescent state
Tuorla Observatory Blazar Monitoring Program
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13. Nadia Tonello, MPI Munich
Crab-1ES1959 comparison
Same cuts applied to Crab and 1ES1959 for each size bin
Size (ph)
Significance
Excess events
1000<S<2000
10.2 
296 ± 29
2000<S<4000
18 
258 ± 14
4000<S<8000
17.3 
166 ± 10
8000<S<16000
4.8 
71 ± 15
CRAB
1000<S<2000
5.0 
364 ± 73
2000<S<4000
4.9 
87 ± 20
4000<S<8000
4.2 
42 ± 10
8000<S<16000
1.5 
29 ± 19
1ES1959
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14. Crab-1ES1959 comparison Excess events/(obs. time * size bin width)
Softer spectrum?
HEGRA System
Results ( ):
94 h obs. Time.
Energy threshold: 2TeV
Significance 5.4
= 3.3 ±0.7
8% Crab flux
43%
12% 9%
14%
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15. Nadia Tonello, MPI Munich
Conclusions
1ES1959 has been observed with MAGIC for ~7 h.
Crab and OFF data (~ 2h each) have been selected to match ZA range: 40 deg.
Data have been analyzed with cuts optimized on Crab.
We have a signal from 1ES when there was no high activity in X-rays
No variation of state, observations are fragmented in time.
Comparison with Crab in size bins:
1ES1959 ~40% to ~10% of Crab, compatible with HEGRA System flux measurements at high energies.
Work in progress: Energy spectrum.
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16. Energy distribution of MC 
1000< s< 2000 ph
~180 GeV
2000< S < 4000 ph
~300 GeV
4000<s <8000 ph
~500 GeV
8000 <s< ph
~900 GeV
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