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

Astronomy & Astrophysics 81 accessible by partly paved roads. Such sites could provide access to sub-mm/THz wavelength bands for astronomical observations. IIA recognized the importance of the Himalayas and pioneered the development of astronomy sites in the high altitude deserts of the Himalayas, specifically, at Hanle, Ladakh. Site testing shows that the precipitable water vapor content of Hanle is similar to that of Mauna Kea. Establishing a sub-mm/THz facility thus needs exploration and development of higher and better sites in the general area which IIA has developed. Ladakh undoubtedly hosts a number of such sites, one prospective site being at the 5000mamsl Pologongka Lamountain pass. The development of a high quality northern sub-mm/THz site and a 15-meter class telescope operating between 200- 1100 GHz at a high altitude desert site will allow India to leapfrog to the forefront of research at these wavelengths. Such a site, in combination with technology and community development efforts, will also allow India to leverage international collaborations on an equal footing. Efforts in this direction have already begun, with the Space Applications Center (SAC) of ISRO currently in the process of establishing a 6-meter facility at Hanle, operating up to 350 GHz (850 mwavelength). Identification, characterization, development of a site and the parallel development of a 15-meter class antenna and associated instruments will be a mega science project that will propel India and Indian astronomers to doing the cutting edge science in sub-mm wave astronomy and the emerging field of THz astronomy. The location of a 15-meter antenna operating in the Tera-Hertz frequencies in India will bridge the longitudinal gap in the global network of telescopes which operate synchronously to synthesise the earth sized telescope called the Event Horizon Telescope (EHT), through the Very Long Baseline Interferometry (VLBI) technique. The EHT recently imaged, for the first time, the signatures of a supermassive black hole at the center of the M87 galaxy, captivating the entire world. A facility in India, such as the one proposed to be located in Ladakh, will improve the resolution of the images obtainedwith the EHT, providing greater details of supermassive black holes. The science drivers for a 15-meter sub-millimeter facility include: questions pertaining to the process and efficiency of star-formation, and the impact of the galactic environment as well as turbulence in the Local Universe; discovery of actively star forming galaxies visible only in the sub-mm; 3-D clustering of star-forming galaxies to understand structure formation; probing the underlying dark matter density fluctuations and the Sunyayev-Zeldovich effect in the distant Universe; and sub-mm study of exotic phenomena such as variable protostars, GRB afterglows and counterparts of fast radio bursts in theTransient Universe. This proposal is a collaborative work of members of the Indian Sub- mm-wave Astronomy Alliance (ISAA), that brings together scientists fromTIFR, IIST, RRI, IIT-Indore, IISc, NISER and IIA. 5.3.6 GroundBased -rayAstronomy The journey of -ray astronomy in India using ground-based Cherenkov telescopes over the last two decades has experienced an era of very encouraging and impressive advances at both scientific and technological fronts. To enable more effective and significant contributions in this vibrant, emerging field of gamma-ray astronomy, the future design and development plans are as outlined below: • Major upgrade of the existingTACTIC telescope at MountAbu. • Development of Silicon Photomultipliers (SiPMs) based 256-pixels imaging camera. After successful μ ɤ ɤ MEGA SCIENCE VISION-2035