MSV-2035 Astronomy Document - Inside Design - FINAL - FINAL

Astronomy & Astrophysics 61 MEGA SCIENCE VISION-2035 resolution spectroscopy in the optical region, a near-Infrared spectrometer camera imaging and low resolution spectroscopy (TIRSPEC) in the near-IR regions, and a high resolution optical spectrometer (HESP) with a resolution of R ~ 30000 - 60000. IUCAA, Pune also installed a 2.0-meter optical and near-IR telescope at Girawali in November 2006. The telescope is equipped with a faint object spectrograph with polarimetric capabilities and a near-IR imaging camera. IUCAA has recently built an autonomous laser-adaptive-optics system for IGO called ROBO-AO. A 2.5- meter telescope was recently installed at PRL's Gurushikhar Observatory. This telescope has instruments that will enable photometry, polarimetry and low-medium and high resolution spectroscopy in the optical and near-IR wavelength regions. The 2-meter class telescopes have proved to be the work horse instruments for optical-NIR astronomy in the country. They are used for observations of objects ranging from the nearby solar system to high redshift quasars. A few areas with significant contribution has been in (i) studies of transients such as novae, supernovae and gamma-ray burst sources, (ii) variability in stellar sources, (iii) chemical abundances in the atmospheres of stars in our Galaxy and the local neighbourhood, (iv) studies of star forming region in the MilkyWay galaxy and nearby starburst galaxies, (v) time variability studies of broad absorption line quasars, (vi) intra-night variability in active galaxies, (vii) reverberation mapping studies to measure the mass of the black hole in AGNs, and (viii) estimation of H using 0 strongly lensed galaxies. The 4-meter class telescopes: India entered the category of countries with 4-meter class telescopes in 2016 with the installation of the 3.6-meter Devasthal Optical Telescope (DOT), located at the Devasthal Observatory operated by ARIES. The DOT is currently the largest optical-IR telescope inAsia. The telescope fills a large longitudinal gap in the 4-meter class telescopes in the Asia region. The telescope is also the first of its kind in India that features an active optics system, a wavefront sensor and pneumatic actuators which compensate for small distortions in the shape of the 4.3 tonne mirror due to gravity or atmospheric aberrations. This feature enables obtaining images of the sky at sub- arcsecond spatial resolutions. The telescope is equipped with a suite of instruments, an optical CCD imager, a low resolution optical spectrograph, a near-infrared spectrograph in the 0.6-2.2 m range and a near-IR imager in the 1-4 m range, providing imaging and spectral capabilities in the visible and near-infrared bands. Deeper imaging and spectroscopy in optical and NIR wavelengths of Galactic and extra-galactic point sources and objects with low surface brightness are the broad scientific objectives of the 3.6-meter DOT. It is also planned to conduct optical observations of new sources discovered using the GMRT and the AstroSat. Considering longitudinal advantage, the DOT is alsowell-suited for observations of many time-critical and transient events including follow-up of Gravitation-Wave sources in a larger perspective of time domain astronomy. To maintain this largest optical observing facility as a productive one during the coming decade plans are underway to upgrade the facility and equip it with newbackend instruments such as a fiber-linked integral field spectrograph and a high resolution spectrograph. Another unique facility, the 4.0-meter International Liquid Mirror Telescope (ILMT) facility, developed in collaboration with Belgium, Canada and Poland is now operational at Devasthal. The mercury mirror of the ILMT has a 4-meter diameter with an aperture of f/2 defined by the speed of rotation. The telescope is equipped with a 4Kx4K CCD camera for imaging in the 4000 to 11000 Å spectral range. Given the zenith observing mode of a liquid mirror telescope, the location of the Observatory at a latitude of ~ 30⁰ N is ideal for surveying the north galactic pole. Adeep μ μ