By Satyaki Paul
The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a Canadian radio telescope located at the Dominion Radio Astrophysical Observatory. This is a national facility for astronomy operated by the National Research Council of Canada.This radio telescope was designed to answer major questions in astrophysics and cosmology.
CHIME is aninnovative radio telescope that has no moving parts. Initiallyit was conceived to map the most abundant element in the universe—hydrogen—over a good fraction of the observable universe, this unusual telescope is optimized to have a high “mapping speed”, which requires a large instantaneous field of view (~200 square degrees) and broad frequency coverage (400-800 MHz). The digitized signals composedtogether by CHIME will be processed to form a 3-D map of hydrogen density, which will be used to measure the expansion history of the universe. Furthermore, these signals can be combed for fast, transient radio emission, making CHIME a unique telescope for noticing new “Fast Radio Bursts” (FRBs) and for monitoring various“Pulsars”(it is an extra-terrestrial source of radiation that has a regular periodicity, usually detected in the form of short bursts of radio emission.) on a day-to-day basis.
The “Fast Radio Bursts” (FRBs) are very brief (few millisecond) bursts of radio waves coming from far beyond our Milky Way galaxy. This phenomenon was first observed in 2007 and as of mid-2017, around two dozen have been reported. Their source is unidentified. Nevertheless, they are omnipresent: current best approximationsproposethat these events are incoming at Earth around1000-times per day over the entire sky.
In this context, CHIME telescope’s large collecting area, wide bandwidth and enormous field-of-view make it a superb detector of FRBs.Scientists from Indian counterpart are also included in this project, such as:Researchers from Tata Institute for Fundamental Research (TIFR) and the National Centre for Radio Astrophysics (NCRA). They have assembled the largest collection of fast radio bursts (FRBs) in the telescope’s first FRB catalogue (535 new fast radio bursts).The scientists plan to use the bursts, and their dispersion estimates, to map the spreading of various gas throughout the ever-expanding universe.
All these leads to a question that: Why study FRBs?Through observations of such phenomenon’s the scientists, astrophysicists and astronomers hope soon to find out the extreme backgrounds of these inquisitively bright signals i.e., FRBs. The author works as a Ph.D. Research Scholar at the Department of Anthropology, University of Calcutta, and the co-author of the book Anthropology For All (2021).