Dr. Supriyo Ghosh

Astronomical instruments are essential for exploring the cosmos effectively. Such instruments, from development to science observation, progress through several key stages: design, lab testing, integration with existing systems, on-sky commissioning and calibration, and maintenance and upgrades. In addition, special attention needs to be given to consistent data reduction to optimise science observations. Essentially, these rigorous processes pave the way for revolutionary scientific discoveries. In my presentation, I would discuss various stages of astronomical instrumentation projects. To begin with, I will present the technology development for an optical high-resolution fibre-fed radial velocity instrument, the EXOplanet high-resolution SPECtrograph (EXOhSPEC). The primary motivation of this project is to develop a high-resolution spectrograph using commercially available components, thereby reducing size and cost without a modest impact on performance. I shall talk about the basic spectrograph design and its components, as well as the test results on active stabilisation, mitigating modal noise and a wavelength calibrator such as a metal-coated etalon from our laboratory prototype. After that, I shall talk about the commissioning and calibration results of the TIFR-ARIES Near Infrared Spectrometer (TANSPEC) instrument on the 3.6-m Devasthal Optical Telescope (DOT), which is one of the few instruments in the world having simultaneous continuous wavelength coverage from 0.55 to 2.5 microns. I will then present the installation of TIFR Near Infrared Imaging Camera-II (TIRCAM2) from the DOT main-port to the side-port and its performance on the DOT side-port. It was a major milestone, increasing the efficiency of the DOT telescope with two instruments available each night for simultaneous observations. Finally, I shall present the development of the first version of the TANSPEC data-reduction pipeline, which was made available to its users for consistent data reduction and to reduce data reduction time.