Context
Black holes in Webb data allay threat to cosmology’s standard model
About Black holes
- A region in space where gravity is so strong that not even light can escape.
- Predicted by Einstein’s theory of general relativity.
- Types of Black Holes:
- Stellar-mass, Supermassive, Intermediate-mass, and suspected Primordial Black Holes.
- Little Red Dots:
- Massive black holes at the centre of ancient galaxies emit light, complicating star mass measurements.
- These black holes, referred to as “little red dots,” could lead to overestimation of galaxy mass in studies of the early universe.
Standard Model of Cosmology
- Universe’s Evolution:
- The standard model of cosmology explains the universe’s origin and evolution, stating that the first stars formed 100-200 million years after the Big Bang, and the first galaxies within 1 billion years.
- Star Formation Efficiency:
- The model suggests that inclusive physical conditions and abundant gas in the early universe led to efficient star formation.
- Large-Scale Structure:
- The bulk of the large-scale structure of the universe is shaped by dark matter, not by variations in star formation rates.
James Webb Space Telescope (JWST) Finding Deviation
- JWST Launched by NASA
- Aimed to study the formation of galaxies and stars in the early universe.
- Unexpected Findings:
- JWST detected massive, well-developed galaxies only 400-650 million years after the Big Bang, which was much earlier than expected based on the standard model.
- These findings posed a challenge to the standard model, as the presence of such massive galaxies early in the universe contradicted expectations of infant galaxies.
- Explanation for Deviation
- New Study (August 26): suggested that early galaxies might have formed stars more efficiently than modern galaxies, which could explain their rapid development.
- Revised Mass Estimates:
- When black hole light (the “little red dots”) was excluded from galaxy mass estimates, the galaxies were found to be less massive than previously thought, aligning with the standard model predictions.
- Future Research:
- Researchers plan to expand data from JWST to study galaxies at higher redshifts and masses, which will help refine the understanding of galaxy formation in the early universe.
Source: TH
Previous Year Question
Recently, Scientists observed the merger of giant blackholes billions of light-years away from the Earth. What is the significance of this observation?
[UPSC Civil Services Exam – 2019 Prelims]
(a) ‘Higgs boson particles’ were detected.
(b) ‘Gravitational waves’ were detected.
(c) Possibility of inter-galactic space travel through ‘wormhole’ was confirmed.
(d) It enabled the scientists to understand ‘singularity’.
Answer: (b)
