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

Astronomy & Astrophysics 30 plan strategies and experiments related to the “Epoch Of Reionization”. Large progress in terms of volume and redshift coverage of these studies is expected with the upcoming facilities that will provide wide area and frequency coverage with enhanced sensitivity. There are active plans for building next generation radio astronomy facilities at much larger scales, of which the biggest one is the Square Kilometre Array (SKA) which involves most of the countries active in the field of radio astronomy as partners. The SKA, with completion of Phase-1 slated towards the end of the present decade, is expected to revolutionise our understanding of the Universe in various domains. The Indian community is part of SKA and will have direct access to the telescope from the very beginning. 3.3 X-rays and -rays At present, many space-based X-ray and -ray observatories are being used to study high energy radiation from astronomical sources. These include: AstroSat, Chandra, XMM-Newton, Swift, Integral, NuSTAR, NICER, Insight- HMXT, eROSITA, IXPE and Fermi. Additionally, there are a few ground-based facilities like the MAGIC Florian Goebel Telescopes, the High Energy Spectroscopic System (H.E.S.S) array and the recently commissioned MACE telescope located at Hanle, that are used to study very high energy (VHE) -rays. The various X-ray and -ray telescopes, with their unprecedented sensitivity and angular resolution, have helped astronomers make significant progress in addressing many of the key questions listed in the previous sections, particularly those related to black holes and explosive events. For example, by studying the shock wave associated with supernova explosions, cause and circumstances of the death of the stars have been identified. By mapping the radioactive material in supernova remnants constraints have been put in the theories of the exact mechanism of stellar explosions. X-ray emission from gas particles seconds before they plunge into a black hole may be observed and that provides crucial information about the physical properties of inflow near black holes: black hole spin has been estimated using how strong gravity would affect the emission lines produced by hot gas very close to the black hole. Observations of compact objects in other galaxies have been made, which may potentially be the elusive intermediate mass black holes. The equation of state of neutron star matter has been probed. Collimated jets of magnetized plasma moving at speed close to the speed of light have been observed to extend up to hundreds of thousands of light years from the center of the galaxy. These are ideal laboratories to study acceleration of particles to high energies at a scale which are not possible to be reproduced on the Earth. Our understanding of the formation and evolution of galaxies have been revolutionised by studying the interaction of these powerful outflows with the interstellar and intergalactic medium. It has been discovered that X-ray emitting hot gas surrounding galaxy clusters corresponds to 90% of all atoms in the Universe. In addition, deep X-ray surveys with Chandra and all sky survey with eRosita is leading to the discovery and identification of new AGNs and clusters of galaxies. The IXPE, launched in 2021, is studying X-ray polarisation from a variety of objects. Another X-ray telescope XRISM, with relatively moderate capabilities was recently launched in late 2023. Several X-ray Astronomy missions are under development or under review for launch in the present or next decade. The major X-ray Astronomy mission approved for development is ESA's ATHENA (Advanced Telescope for High- Energy Astrophysics) mission selected under the Cosmic Vision Program to explore the “Hot and Energetic” Universe. ATHENA will operate in the energy range of 0.2-12 KeV and will offer spectroscopic and imaging ɤ ɤ ɤ ɤ MEGA SCIENCE VISION-2035