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

Astronomy & Astrophysics 37 mergers and providing precise sky localisation in conjunction with the ground-based detectors, can observe interesting sources like intermediate mass black hole (IMBH) mergers and, perhaps, the enigmatic primordial gravitational waves generated in the very early Universe, right after the Big Bang, when the Universe was less than a second old and went through a phase of rapid expansion (the Cosmic Inflation).While Cosmic Inflation is a fundamental pillar of the standardmodel of Cosmology, presently, there is no direct evidence for it. Detection of primordial gravitational waves can provide a smoking gun evidence for Cosmic Inflation and pin-point its correct theoretical model. At present there is no funded mission in the Deci-Hertz band. With the expertise of the Indian space agency, and with the growing LIGO-India experimental community, India may be able to lead a future Deci-Hertz Gravitational Wave spacemission, perhaps with international collaboration. Other detectors : Pulsar Timing Array (PTA): Pulsars, which are spinning neutron stars, emit pulses at very precise intervals. GW passing through the line of sight between pulsars and the earth perturb the delay in receiving these pulses fromdifferent pulsars in a coherent way, enabling us to detect the source of GW. A well understood and calibrated set of pulsars, called the Pulsar Timing Array (PTA), monitored with highly sensitive modern radio telescopes, can be used for this purpose. The uGMRT is a part of the pulsar timing array programme. Very low-frequency (nano-Hertz) signal from pulsars, that may be attributed to GW, has been recently detected by the participants of the International Pulsar TimingArray, that also includes the Indian Pulsar Timing Array (InPTA) group. This result is a major step for GW at nano-Hz frequencies. The Square KilometerArray (SKA) has excellent prospects of detecting GW from inspiralling supermassive black holes. 3.7 SolarTelescopes The Sun is a unique astrophysical system, not only providing a window to understand plasma astrophysical processes in the Universe through spatially resolved observations, but also affecting humanity directly and impacting our space- reliant technologies. This realisation over the last several decades – with our ever increasing reliance on space assets – has led to concerted global efforts both by advanced space-faring nations as well as international agencies to explore the Sun. These endeavours include the already functional, state-of-the art Daniel K. Inouye Solar Telescope (DKIST) – a 4-m class telescope in Hawaii funded by the United States (US) National Science Foundation and the under- development, European Solar Telescope, a 4.2-m class telescope being developed by a consortium of countries and funded by the EuropeanUnion. Multiple ongoing space missions of the US National Aeronautics and Space Administration (NASA), the European SpaceAgency (ESA) and the JapaneseAerospace ExplorationAgency (JAXA) are currently observing solar dynamic activity, solar space storms and its impact on the Earth's magnetosphere. The two major workhorses in this regard are ESA's SOlar and Heliospheric Observatory (SOHO) and NASA's Solar Dynamics Observatory (SDO) which have been observing various aspects of solar activity, including its internal flows, surface magnetic fields, atmospheric dynamics and radiation. Other ongoing missions such as Advanced Composition Explorer (ACE) and WIND are making in-situ near-Earth particle and magnetic flux observations that perturb geospace and have space weather consequences. Notably, two pioneering missions have recently joined this fleet of space-based solar observatories. The major goals of ESA's Solar Orbiter mission with a novel out-of-ecliptic orbit are to observe the Sun's polar • MEGA SCIENCE VISION-2035