1. Bulgarian Participation in the MAGIC Experiment H. Vankov, Institute for Nuclear Research and Nuclear Energy of Bulgarian Academy of Sciences, ECFA Meeting, Sofia 2010

2. MAGIC (Major Atmospheric Gamma-Ray Imaging Cherenkov) Telescope Last-generation instrument for very-high energy γ-astronomy (VHE): 17m Ø (world largest!) Location: Observatorio del Roque de los Muchachos on Canary Island of La Palma (Spain), 2250 m a.s.l. In operation since fall 2004 High resolution camera Enhanced duty cycle (moon observation) by ~ 50% Active mirror surface 236 m 2 Trigger threshold ~ 60 GeV →~ 25 GeV Sensitivity ~ 1.6% of Crab (50h at 270 GeV) Angular resolution ~ 0.1 degrees Energy resolution ~20-30% Fast rotation for GRB (for < 40 sec) What is MAGIC ? MAGIC - I Low-medium energy 0.1 MeV – 20 MeV HE 20 MeV – 30 GeV VHE 30 GeV – 30 TeV UHE 30 TeV – 30 PeV EHE 30 PeV – no limit Gamma-astronomy is one aspect of astroparticle physics → new field developing as an intersection of Particle Physics, Nuclear Physics, Astrophysics, Gravitation and Cosmology M-II at 86 m distance, finer camera pixelization, improved angular resolution (~ 0.07 deg), increased sensitivity (http://wwwmagic.mppmu.mpg.de

3. MAGIC Collaboration About 150 scientists, funding agencies - BMFB (Germany), MPG (Germany), INFN (Italy), MICINN(Spain), and the ETH Zurich (Switzerland) Many physicists came to MAGIC from HE physics.

4. Physics goals To understand particle acceleration To understand the origin of cosmic radiation To detect the annihilation products of dark matter To understand gamma ray bursts To discover new types of sources, unseen at other wavelengths I.Galactic sources: pulsars and PWN, SNR, binary systems with accretion Galaxy center (GC)… I.Extragalactic: AGN (blazars and radio-galaxies), GRB, galaxy clusters, starburst and merging galaxies… III.Fundamental physics: DM annihilation or decays, EBL, cosmological gamma-ray horizon, possible quantum-gravitational effects (LIV), antiparticle asymmetry… Targets

5. Electromagnetic and hadronic showers have different shapes Using a high resolution camera allows to distinguish (statistically) between  - and hadron- showers Signal-to-noise ratio << 1%! We need powerful methods of hadronic rejection! IAC Technique

6. The four big IACTs HESS

8. Galactic sources Operating since 2004 First pulsar detection by Cherenkov telescopes Relatively high-energy spectral cutoff

9. Extragalactic sources 3C 279: blazar, z=0.536 (distance ~ 5.3 bln of l.y.)→ the most distant VHE emission, the “oldest” VHE γ ! Conclusion about EBL!

10. Bulgarian participation 5 scientists from the Laboratory of Particle and Astroparticle Physics in the INRNE of the BAS. Data analysis - developing of a new intelligent method and software for discriminant analysis, based on Hierarchical Artificial Neural Networks. - developing an intelligent hierarchical regressor designed to provide statistical energy evaluation for an individual Cherenkov shower, in the space of the image parameters.

11. Modeling and development of correction methods for light attenuation in the atmosphere - A detailed study of the atmospheric extinction measurements performed by the optical astronomical telescopes, situated on the same place (Roque de los Muchachos, La Palma). - Development of theoretical methods for deriving the attenuation of the triggered Cherenkov showers from the accessible astronomical measurements of the full starlight atmospheric extinction. - Development of analysis methods for data correction aiming the minimization of the systematic bias of the flux and energy spectrum of MAGIC gamma measurements. Participation in the observation runs - 2 shifts for a period of 28 days each one every year. Up to now we had 168 shift-days.  Continuous daily-check of the MAGIC data quality Everyday on-line control of the data, registered during the night observations (stability of all elements of the experimental apparatus and control of the external factors, such as atmospheric conditions, during the observation period) - The Bulgarian group of MAGIC-collaboration is one of the three groups (from more than 20 research groups from different European countries) which are responsible to execute this daily-check control on the quality of the detected data. - 2 times by 2 months per year. All our activities in MAGIC are supported from the NSF of the MEYS under the grant DO02-353 (2009-2011)

12. Main results 10 new sources discovered (4 galactic and 6 extragalactic). Observed and studied 12 (6 galactic and 6 extragalactic). Upper limits estimated for VHE emission from some binaries, dark matter, GRB’s, M QG, etc. More than 50 scientific publications in referred journals. 4 articles in “Science”. More than ~ 1200 citations.

13. Future - MAGIC two telescope system is the best / the most sensitive instrument in the world in the next several years. - HESS-I, -II and VERITAS can not be competitors below ~ 200GeV. - The lifetime of the MAGIC can be ~ 10years from now. 1. MAGIC

14. European project for the future generation of IACTs, planned to explore the whole sky in the energy range of gamma-rays between ~ 10 GeV and ~ 100 TeV Partnership between the HESS and MAGIC +…. ~ 50 institutes, 14 countries, 300 scientists Recommeneded by ApPEC (Astroparticle Physics European Coordination) in its strategic document about the general plan for the future –the so- called “roadmap” - a concentration of resources of European countries towards several large projects in the field of astroparticle physics as the priority project of European gamma-ray astronomy. 2. CTA (Cherenkov Telescope Area) Next generation of Cherenkov telescopes

15. CTA concept 4 to 100 telescopes Large area 1 – 10 km 2 2 -3 different sizes Using well-proven technology of current IACTs High automatization and remote operation Full sky coverage Observatory open to astronomer community 1.To decrease the energy threshold to few tens of GeV 2.Sensitivity beyond 50 TeV 3.To increase sensitivity in the range 100 GeV – 50 TeV (at least by 10) 4.To improve energy and angular resolution Cost ~ 150 - 170 ME

16. 16 Core array: mCrab sensitivity in the 100 GeV–10 TeV domain Low-energy section energy threshold of some 10 GeV High-energy section 10 km 2 area at multi-TeV energies From V. Hofmann

17. Our participation At present, Bulgarian group in MAGIC actively participates in the intensive discussions about CTA which final design is expected to be ready by the end of 2010 (2011?). Our task: “Monitoring of the atmosphere and modeling its impact on Cherenkov photons propagation in a night-by-night and even hour-by-hour time scale”. (project for NSF is prepared) Consortium between INRNE group, Institute of Astronomy of BAS and Department of Astronomy of Sofia University

18. Thanks

19. >1.2 TeV < 0.25 TeV 0.25 – 0.6 TeV 0.6 – 1.2 TeV Mkn 501, LC for July 9 (2005), Δτ H-L = 4 ± 1 minutes Astrophysical probe of the constancy of the velocity of light Albert et al. 2008 ApJ, 675, L25

20. The SNR in Scorpius RX J1713.7-3946 H.E.S.S. image

21. Neutralino (lightest SUSY particle) is a possible candidate Annihilates with itself Mass between 60 GeV and 1 TeV Concentration around center of galaxy Large zenith angle observation at 70°  high sensitivity

22. Origin of high-energy gamma-rays

24. The main project objective: To study and develop adequate multi- parametric methods for atmosphere monitoring, based on multi- wavelength astronomical measurements and direct physical and chemical aerosol measurements. Such methods should permit us to develop a model (and the necessary software products) of the Cherenkov shower photons propagation through the atmosphere, and the corresponding impact on IACT's images.

26. From M.Teshima’s presentation at CERN, 2008

27. The stereoscopic technique View of the atmospheric shower from different angles (stereoscopic). 3D-reconstruction of the shower geometry (event- by-event). High background rejection. High energy resolution