CHIME Telescope Makes First Solo Detection of Hydrogen Glow

The correct answer is Canadian Hydrogen Intensity Mapping Experiment. CHIME is an interferometric radio telescope in Canada, built to map the distribution of hydrogen gas in the early universe so that astronomers can calculate how the universe expands and thereby study dark energy. Options A, C and D are invented expansions assembled from similar astronomical vocabulary, which is the usual way such distractors are framed. Note that the first letter stands for the country that conceived, built and funded the instrument, a point its principal investigator emphasised. Candidates should also register that CHIME works at radio wavelengths and has no moving parts, scanning the sky as it drifts overhead, which is what lets it deliver a daily view of the radio sky.

The correct answer is the Raman Research Institute. The study that reported the first standalone detection included CHIME collaborators at RRI, an autonomous institute of the Department of Science and Technology, and its associate professor Saurabh Singh is among the co-authors quoted on the result. Options A, B and D name other well known Indian research bodies working in astronomy, space and fundamental physics, and they are placed here precisely because a candidate who remembers only that an Indian institute was involved may pick any of them. The safe approach is to link the institute to its parent department as well, since questions often ask which ministry or department the institute falls under, and here the answer is the Department of Science and Technology.

The correct answer is about two per cent. An accompanying paper examined what the observed signal reveals about the distribution of hydrogen, and co-author Shabbir Shaikh of Arizona State University said the data indicate that roughly this share of the universe's hydrogen was in neutral atomic form at that time, broadly consistent with other measurements. Options B, C and D overstate the neutral fraction by a wide margin and are wrong. The wider point for an aspirant is why this matters: by measuring how that hydrogen is distributed and clustered, CHIME offers a new way to test our understanding of how galaxies form and evolve, which is a separate payoff from its main goal of probing dark energy. Candidates should also note that hydrogen is described as the most common element in the universe and the raw material from which stars form, which is why its faint radio emission works as a cosmic tracer.

The correct answer is 2019. The measurement rests on 94 nights of observation data collected in that year, which is only a small fraction of everything the telescope has recorded since operations began. Options A, C and D are nearby years offered as distractors and do not match the announcement. Two related details are worth carrying alongside the year. First, the finding was not immediate: new analysis and processing techniques were needed to pull the faint signal out of the noise, and the team spent more than a year testing it before publishing in The Astrophysical Journal. Second, researchers now have nearly seven years of observations and are extending the work to when the universe was about three billion years old.