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

Astronomy & Astrophysics 31 capabilities.ATHENA's planned capacities, in particular its energy resolution, are 1-2 orders of magnitude better than those of current facilities. However, it will probably not be launched before 2030. Other proposed missions are the SVOM(France and China) andThesesus (ESAM5 proposed). The Compton Spectrometer and Imager (COSI, USA) is a -ray telescope expected to be launched by NASA in 2025. It will study the recent history of star birth, star death, and the formation of chemical elements in the MilkyWay. There are other -ray telescopes proposed like the e-ASTROGAM, that will be very similar to Fermi but with an angular resolution that is 4-6 times better than Fermi, the HERD (China) and the GAMMA-400 (Russia). 3.4 Large Sky Surveys All sky surveys play an important role in astronomy. They are extremely important to (i) build any unbiased volume limited as well as flux limited samples of different kinds of astronomical sources to quantify their spatial distribution and time evolution, (ii) quantify the time variability properties of different sources, (iii) find unexpected class of objects and (iv) monitor a wide range of variable and transient sources at a higher cadence. Such surveys have helped us constrain cosmological parameters, dark matter distribution in the universe and discover various spectacular transient sources such as peculiar SNe, GRBs, FRBs, FBOTs, tidal disruption events, etc. 3.4.1 GroundBased Surveys In the past decade the Sloan Digital Sky Survey (SDSS) has made a huge impact in nearly every aspect of astronomy, through regular and highly organised photometric and spectroscopic data releases. Interestingly, the main survey is been carried out using a 2.5-m optical telescope. The large scale structures probed by galaxies and quasars (and IGM absorption detected in their spectra) found by the SDSS survey have provided important constraints on various aspects of the Big Bang model. In particular, detection of Baryonic Acoustic Oscillations (BAO) in the galaxy distribution at low redshift (nearby) and IGM matter distribution at high redshift (distant) are very important results. Thanks to the well organised data archive, SDSS data are used by astronomers around the world to address various scientific questions and also construct unbiased sample for detailed investigations using larger telescopes. Similarly, near-IR all sky data obtained using Two Micron All-Sky Survey (2MASS) and United Kingdom Infra-Red Telescope (UKIRT) Infrared Deep Sky Survey provided useful catalogues of near-IR sources. In the radio, high frequency surveys using Very LargeArray: NewVLASky Survey (NVSS), the Faint Images of Radio Sky at Twenty centimetres (FIRST) and the Very LargeArray Sky Survey (VLASS) have played an important role in our understanding of the radio Universe. Low frequency radio surveys such as the TIFR GMRT Sky Survey (TGSS), the GaLactic and Extra-galactic All-Sky MWAsurvey (GLEAM) and the LOFARTwo-metre Sky Survey (LoTSS) have provided very interesting insights into our understanding of the Universe at low frequencies, and of various relic radio sources. At present, several optical, near-IR and radio all sky surveys are pursued by the astronomy community with an aim to map large volumes of the Universe at a much higher accuracy than SDSS. These include the Dark Energy Survey (DES), carried out using the 4-m Blanco telescope, its spectroscopic counterpart Dark Energy Spectroscopic Instrument (DESI) survey using the 4-mMayall telescope in Chile and theVisible IR SurveyTelescope forAstronomy (VISTA) using the 4-m ESO telescopes. The Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST), Guo Shoujing Telescope (China) is conducting a wide-field survey, the LAMOST Experiment for ɤ ɤ MEGA SCIENCE VISION-2035