According to the study, how does a black hole jet affect the gas around a galaxy?
- A.It cools the gas equally in all directions so that stars form faster
- B.It energises the gas only along its own direction and suppresses star formation
- C.It pulls the entire gas envelope into the black hole within a few years
- D.It has no measurable effect beyond the central region of the galaxy
Correct answer
Explanation
The correct answer is that the jet energises the gas only along its own direction and suppresses star formation. When the team averaged their measurements over all directions around the galaxies they picked up no signal, but when they probed along the direction of the jet they found a strong one, which showed that the jet illuminates only the gas in its path. The signal was strongest where the jet first meets the outer gas at the rim of the stellar disc, and again at the outer boundary of the envelope where the slowed jet strikes once more, depositing energy at both places. Because cool gas is needed for gas to clump into stars, this heating keeps the galaxy quiet and passive, so option A is the opposite of the finding. Options C and D are ruled out for the same reason, since the study shows an effect reaching far beyond the centre.
Read the full article: RRI Study Shows Black Hole Jets Choke Star Birth in Galaxies
Practice Questions
The circumgalactic medium (CGM) referred to in the study is best described as
- A.The dense core of a galaxy where stars are packed together
- B.The faint envelope of gas surrounding a galaxy beyond its disc
- C.The ring of dust that forms the spiral arms of a galaxy
- D.The region inside the event horizon of a black hole
Show answer
The study describes the circumgalactic medium as a diffuse, ghostly reservoir of gas that lies past the edge of the stellar disc and spreads out to between ten and twenty times the size of the galaxy, and this reservoir supplies the fuel from which stars are eventually made.
Read the full explanation →Which Indian institute, along with Arizona State University, carried out the study on black hole jets and star formation?
- A.Indian Institute of Astrophysics
- B.Raman Research Institute
- C.Physical Research Laboratory
- D.Tata Institute of Fundamental Research
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The lead author of the paper, published in The Astrophysical Journal Letters, is Namrata Roy, an assistant professor in the astronomy and astrophysics division of that institute, and a co-author quoted on the finding is Sanchayeeta Borthakur of the American university.
Read the full explanation →As of 6 November 2026, how many equipment items were listed on the I-STEM portal?
- A.4,044
- B.18,250
- C.31,540
- D.45,000
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As of 6 November 2026, the day its API integration with the Startup India Portal was launched, I-STEM listed 31,540 equipment items across 4,044 registered institutions, giving researchers and innovators a large national pool of scientific resources.
Read the full explanation →Who chaired the launch of the API integration between the Startup India and I-STEM portals on 6 November 2026?
- A.Dr. Parvinder Maini
- B.Prof. Ajay Kumar Sood
- C.Ateesh Kumar Singh
- D.Dr. Vishal Choudhary
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He described the integration as an institutional convergence that can lower R&D costs, avoid duplication of capital-intensive facilities and raise the use of publicly funded infrastructure.
Read the full explanation →What does the acronym I-STEM, whose portal was integrated with the Startup India Portal in November 2026, stand for?
- A.Indian Scheme for Technology and Engineering Mentorship
- B.Indian Science, Technology and Engineering Facilities Map
- C.Integrated Startup Technology Enablement Mission
- D.Indian Society for Technology, Engineering and Mathematics
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I-STEM is the portal that maps scientific equipment and research facilities across academic and research institutions so that they can be shared.
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