Staff Reporter

KODAIKANAL: Efforts were under way to establish an Indian Neutrino Observatory (INO), aimed at building a world-class underground laboratory to study fundamental issues in particle physics and astrophysics. With the experiments in these frontier fields of neutrino and gamma ray astronomy, India had a variety of telescopes to study neutral particles (photons and neutrinos) from the lowest to highest energies, said K. Sundara Raman, Scientist-in-charge, Institute of Astrophysics, Kodaikanal.

Addressing a meet on high energy astrophysics here for Ph.D students and recently completed M.Sc., B.E. and B.Tech. students from universities and faculties around the globe here recently, he said that diverse fields such as particle physics, astrophysics, instrumentation, electronics, numerical simulations, and analysis had been covered in these courses. Eighteen scientists from different institutes had been giving lectures.

Gamma rays were the most energetic form of electromagnetic radiation. They had over a million–billion times more energy than ordinary visible light. Gamma-ray astronomy presented unique opportunities to explore exotic celestial objects such as supernovae, neutron stars, black holes and active galaxies. By exploring the universe at these high energies, one could search for new physics and testing theories.

Gamma Ray Astronomy was being studies using huge and expensive telescopes. However, our approach in India had been to use relatively less expensive equipment and conduct these experiments at very high altitudes.

With this idea in mind, a new experiment called HAGAR (High Altitude Gamma Ray Experiment) was commissioned at Hanle at an altitude of 4,300 metres above sea level last year.

Hanle, situated in Ladakh, had the world’s highest optical telescope, providing the right altitude for these studies. The important aim in these experiments was to achieve very low energy thresholds and studies showed that there was already a marked improvement in HAGAR compared to earlier experiments at lower altitudes. Preliminary results from this experiment were also very encouraging and efforts were under way to make this more competitive.

Neutrinos were neutral elementary particles which are abundant all over the universe. The sun and all other stars produced neutrinos copiously owing to nuclear fusion and decay processes within their core.

There were many other natural sources of neutrinos, including those produced in cosmic ray interactions in the earth’s atmosphere, he added.

Institute Director S.S. Hasan said that the main aim of this school was to train students in the high energy regions of the electromagnetic spectrum such as the gamma ray as new facilities were coming up. A total of 33 students took part in the programme that began on December 1 and concluded on December 11.