Head of CRD
Name: Prof. Ashot Chilingarian
Fax: 374-10-35 20 41
of Professor Ashot Chilingarian
(Born: May 18, 1949, in Yerevan, Armenia)
Prof. Ashot Chilingarian is the Head of Cosmic Ray Division (CRD) of A.Alikhanyan National laboratory (Yerevan Physics Institute, YerPhI).
Dr. Chilingarian earned his Ph.D. in 1984 and Doctorate of Science in Physics and Mathematics in 1991 from YerPhI. From 1971 to 1993 he was a scientist, senior scientist and data analysis group leader at the Yerevan Physics Institute. In 1993 Ashot Chilingarian became the deputy director of Yerevan Physics Institute, as well as head of the Cosmic Ray Division, in 2008 – 2017 was director of the Yerevan Physics Institute.
Prof. A. Chilingarian has a vast experience in high-energy astrophysics, cosmic ray physics, machine learning, data acquisition, multivariate statistical data analysis, space weather, atmospheric electricity and lightning physics. He has made substantial contribution to the measurement of cosmic ray composition and energy spectrum using facilities on Mt.Aragats, Armenia and in Karlsruhe, Germany. He developed advanced analysis methods for the photon shower identification for Cherenkov telescopes in gamma ray astronomy which substantially enhanced the sensitivity of the gamma ray imaging telescopes.
In 80-ths Prof. A. Chilingarian developed methodology of machine learning for high-energy physics and astrophysics experiments. He is the author of the ANI (Analysis and Nonparametric Inference) computer code library, which has been extensively used during the last few decades for multidimensional analysis of data from modern cosmic ray detectors. He introduced the "multidimensional nonlinear cuts" method for analyzing data from the Atmospheric Cherenkov Telescopes (ACT); these techniques help to reliably proof existence of the flux of very high-energy gamma rays from the Crab nebula measured by the Whipple Cherenkov telescope thus establishing the new window to the Universe. The methodology of the event-by-event analysis of the Extensive Air Shower experiments, introduced by him allows the estimation of the energy spectra of the separate groups of primary nucleolus; the partial spectra of primary cosmic rays measured by MAKET-ANI and KASCADE detectors prove the mass-dependent position of the knee and helps to develop particle acceleration models in Supernovae explosions now confirmed by gamma ray observatories on board of AGILE and FERMI satellites. A.Chilingarian introduced a new probability distribution for calculation of chance probability for the “peak” detection in searches of “new physics”, which will help to avoid fake inference usually occurred when dealing with small statistics and applying multiple cuts.
New statistical models developed by A.Chilingarian, i.e. new multivariate methods of probability density local estimation, Bayesian and neural network models of particle classification and background rejections plays key role in data analysis from most important high energy astrophysics experiments on the particle acceleration in Universe and on gamma ray sources of very high energy. In a new topic of high-energy physics in atmosphere Aragats group first time detects correlated large fluxes of electrons, gamma rays and neutrons from thunderclouds.
Outside his field, Prof. Chilingarian has been interested in applying his data analysis methods to pattern recognition and genome analysis. In 2000-2001 he collaborated with the Huntsman cancer institute in Utah, USA to develop multivariate methods of DNA micro-array data treating based on quantification of different types of gene expression in normal and tumor-affected tissues. This work culminated in a patent application by Utah University.
The main scientific results of Ashot Chilingarian are as follows:
- Discovery of the features of Galactic Cosmic Ray spectra such as: the very sharp change of the power spectral index (~1) for the light nucleus group at 2-4 PeV and no pronounced change in the heavy nucleus group (at least for energies 20-30 PeV). Discovery of the charge depended “knee” in the energy spectra pointing to the shock acceleration initiated by the supernova blasts as a most probable mechanism of particle acceleration.
- Discovery of energetic protons (with energies greater than 20 GeV) accelerated in the vicinity of the Sun on 20 January 2005 during Ground Level Enhancement (GLE) event N 69.
- Discovery of simultaneous fluxes of electrons, gamma rays and neutrons measured at mountain altitudes, proving the existence of the new high-energy phenomenon (so called Thunderstorm Ground Enhancements - TGEs) in the thunderstorm atmospheres.
- Discovery of the “Cloud extensive showers - CESs” – extended showers initiated in thunderclouds by the electrons accelerated in cloud electrical fields – first direct evidence of the Relativistic Runaway Electron Avalanches (RREA) in the terrestrial atmosphere.
- Discovery of long lasting radiation from the thunderclouds (up to several hours) that radically changed fundamental perception of the atmospheric natural radioactivity.
- Development of the Aragats Space Environmental center (ASEC) and Armenian geophysics measurements network. Both are equipped with various particle detectors, field meters and meteorological stations for monitoring of ionization radiation, disturbances of geomagnetic and electric field and lightnings.
- Founding of the worldwide network of new particle detectors for researches in space weather and solar physics, named SEVAN (Space Environment Viewing and Analysis Network). Nodes of the SEVAN network are now operating in Armenia, India, Bulgaria, Croatia and Slovakia.
- Introducing of new model of lightning initiation;
- Founding of Armenian Geophysics Network in 6 location of Armenia and Arcakh.
Connected to these discoveries are many international publications in peer-reviewed journals as Physical Review (Phys.Rev), Astroparticle physics, Atmospheric Research, Nuclear Instruments and Methods in Physics, Advances in Space Research, and many others. The value of the presented work is excellent and is absolutely honoured by the scientific community, which is evidenced by more than 5000 citations.
Currently he is Armenia’s representative to the International Space Weather Initiative. He is the founder and spokesperson for the ANI and ASEC collaborations, and fellow of the American Physical Society, associate editor of the Space Weather and Space Climate (SWSC) journal and serves as reviewer for many international periodicals.
Prof. Chilingarian has authored ~350 scientific publications (with about 50 in the last 5 years) and served on many international scientific and editorial boards. His scientific activities are outstanding in Armenia and especially the atmospheric and lighting research work is world-leading. His group is by far the most prolific science group in Armenia. Prof. Chilingarian has been chairperson of several international conferences, such as “Solar Extremely Events” (SEE-2005), "Forecasting Of the Radiation and Geomagnetic Storms” (FORGES 2008), “Thunderstorm and Elementary Particle Acceleration” (TEPA-2010-2018) and given numerous presentations in the fields of high energy and cosmic ray physics and high-energy phenomena in the atmosphere.
Award: “Data Visualisation Interactive Network for the Aragats Space-environmental Center” – DVIN for ASEC received the World Summit on Information Society award, in Geneva, in December 2003, as the world’s best project in the category of e-science.
Armenia president award in Physics: High Energy Phenomena in the Thunderstorm Atmosphere (2013).
Nomination as best reviewer of Astroparticle physics and Advances in Space Research, Elsevier Journals, 2014;
Armenian Engineers and Scientists of Americas (AESA’s) Scientist of the Year Award – 2017;
First prize of the competition of best scientific publications, Institute of Space Research, russian Academy of science, 2017.
His current interests include the galactic and solar cosmic ray origin and acceleration, atmospheric electricity and lightning phenomena, detection of secondary cosmic ray fluxes at the Earth’s surface, space weather and space climate. Solar particles interact with the magnetosphere, ionosphere and the atmosphere, thus influencing the near-Earth environment and abruptly changing the “space weather”, seriously impacting space-born and Earth-based technologies, including telecommunication, navigation, disaster warning, weather forecasting, military systems, etc. Therefore it is of big importance to study space weather to be able to create reliable forewarning services.
Currently, Prof. Chilingarian is continuing his research projects on Aragats Space Environmental Center and dealing with the following research topics:
1. Research of the high-energy physics in Earth's atmosphere (Aragats research station of YerPhI); High-energy physics in the atmosphere is a new science branch investigated fluxes of elementary particles originated from the relativistic electrons accelerated in strong electric fields of the thunderstorms. Fluxes of particles are directed both to open space where they are detected by orbiting gamma ray observatories and to the Earth’s surface. The largest facilities on the earth’s surface detecting electrons, gamma rays and neutrons (TGEs) as well as radio bursts, electric fields, lightning flashes are located on Aragats in Armenia.
2. Lightning initiation and relation of particle fluxes and atmospheric discharges. The problem of the thundercloud electrification and how lightning is initiated inside thunderclouds is one of the biggest unsolved problems in atmospheric sciences. The relationship between thundercloud electrification, lightning activity, wideband radio emission and particle fluxes have not been yet unambiguously established
Modern science is impossible without a large-scale scientific cooperation; therefore the involving of the young researchers in the international projects from the very beginning is a very important aspect of the education process, which is taken by Prof. Chilingarian accordingly very serious: his new master courses for the new generation of students in Space Education center of YerPhI (courses) has a special emphasis on participation in current international research projects of the institute. Prof. Chilingarian is professor and co-director of Armenian - Russion laboratory of atmospheric research at National Research Nuclear University MEPhI (Moscow Engineering Physics Institute. Recently he joins the Scientific Advisory Committee of the EU project “Research Center of Cosmic Rays and Radiation Events in the Atmosphere, CRREAT” .
Collaborative work with DESY on preparation of CTA experiment and with MAGIC on atmospheric research as well as with the Institute for Data Processing and Electronics in Karlsruhe (IPE, KIT) on development of the platform for multivariate data analysis are such joint projects, where lively international knowledge exchange and long-time experience gained through the practical work on Aragats provide a fruitful ground for better understanding of cosmic rays impact on Earth's atmosphere.
Under supervision of prof Chilingarian, operations of the research at the Aragats research facilities could be secured and further national funds could be triggered and activated to support the research which is an asset to Armenia, and a shining example of clever use of limited means to do internationally competitive science. The research on Aragats is an important signal to the young generation in Armenia, that research is a viable and worthwhile endeavour at their home country. Prof Chilingarian has always managed to attract a sizeable group of young scientists working on cosmic rays and atmospheric electricity. New students generation educated in frame of the master program lead by Prof. Chilingarian and strongly involved in joint projects with International community will for sure contribute for further discovering in the research field concerning the galactic, solar and atmospheric cosmic ray.