Locally designed and developed spectrograph can locate weak light from distant celestial objects

Indian scientists designed and locally developed a low-cost optical spectrograph capable of locating weak light sources from distant quasars and galaxies in a very young universe, regions around supermassive black holes around galaxies and cosmic explosions.

“Until now, these spectroscopes were imported from abroad and involved high costs. The “Made in India” optical spectrograph, called Aries-Devasthal Faint Object Spectrograph & Camera (ADFOSC), was designed and developed by the Aryabhatta Research Institute of Observation Sciences (ARIES), Nainital, an independent institute of the Department of Science and Technology (DST), Government of India, is about 2.5 times cheaper than imported ones and can locate light sources with a photon rate as low as about 1 photon per second, ” read a statement from the Ministry of Science and Technology.

The spectroscope, the largest of its kind among the existing astronomical spectrographs in the country, has been successfully commissioned on the 3.6m Devasthal Optical Telescope (DOT), the largest in the country and in Asia, near Nainital Uttarakhand.

According to the statement, the instrument, a 3.6m DOT backbone for observations of extremely faint celestial sources, uses a complex arrangement of multiple lenses made of special glasses, polished to a smoothness greater than 5 nanometers to produce sharp images of the heavenly sky.

Photons from distant celestial sources, collected by the telescope, are sorted into different colors by the spectrograph and are ultimately converted into recordable electronic signals using an in-house developed and temperature-cooled CCD (Charge-Coupled Device) camera. an extremely low temperature of – 120 degrees Fahrenheit. The total cost of this instrument is almost Rs 4 crores.

Dr Amitesh Omar, scientist at ARIES, led this project with a technical and scientific team who together researched and developed various optical, mechanical and electronic subsystems of the spectrograph and camera.

The spectrograph is currently being used by Indian and foreign astronomers to study distant quasars and galaxies in a very young universe, regions around supermassive black holes around galaxies, cosmic explosions like high energy supernovae and gamma-ray bursts, young and massive stars and faint dwarf galaxies.

“Indigenous efforts to build complex instruments like ADFOSC in India are an important step towards becoming ‘Aatmanirbhar’ in the field of astronomy and astrophysics,” said Professor Dipankar Banerjee, director of ARIES.

Expertise from various national institutes and organizations, including the Indian Space Research Organization (ISRO) and some micro-small and medium-sized enterprises, was involved to review and develop parts of the instrument that serve as an example of collaboration. effective. Building on this expertise, ARIES now plans to order more complex instruments such as the spectropolarimeter and the high spectral resolution spectrograph on the Devasthal 3.6m telescope in the near future. (ANI)