Sign In
Learn bits
Science & Tech.
Pradeep Kumar

09/04/21 09:00 AM IST

Kaleidoscopes in the sky

In news

A group of astronomers have discovered a dozen quasars that have been warped by a naturally occurring cosmic "lens" and split into four similar images.

Details
  • Quasars are extremely luminous cores of distant galaxies that are powered by supermassive black holes.
  • This rare discovery increases the number of known quasars or quads by about 25% and can help determine the expansion rate of the universe and help address other mysteries.
Background
  • Quadruply imaged quasars are rare, and the first quadruple image was discovered in 1985.
  • Over the past four decades, astronomers had found about fifty of these “quadruply imaged quasars” or quads for short, which occur when the gravity of a massive galaxy that happens to sit in front of a quasar splits its single image into four.
Quads
  • The quads are gold mines for all sorts of questions.
  • They can help determine the expansion rate of the universe and help address other mysteries, such as dark matter and quasar 'central engines
Cosmological Dilemma
  • In recent years, a discrepancy has emerged over the precise value of the universe's expansion rate, also known as Hubble-Lemaître’s constant.
  • Two primary means can be used to determine this number: one relies on measurements of the distance and speed of objects in our local universe, and the other extrapolates the rate
  • from models based on distant radiation left over from the birth of our universe called the cosmic microwave background.
  • The problem is that the numbers do not match. The quasars lie in between the local and distant targets used for the previous calculations.
  • The new quasar quads, which the team gave nicknames such as "Wolf's Paw" and "Dragon Kite," will help in future calculations of Hubble-Lemaître’s constant and may illuminate why the two primary measurements are not in alignment.
  • "Machine learning along with Augmented Intelligence (AI) tools was key to our study, but it is not meant to replace human decisions," explains Krone-Martins, Lecture at University of California.
Source: PIB

More Related Current Affairs View All

17 Jan

Groundwater contamination in India

'Of the 15,239 groundwater samples collected from across the country for testing, 19.8% samples had nitrates — nitrogenous compounds — above safe limits though it must

Read More

17 Jan

Draft data protection rules

'The Ministry of Electronics and Information Technology on January 3, 2025, released the the draft rules for implementing the Digital Personal Data Protection (DPDP) Act, 2023 &mda

Read More

16 Jan

INS Surat, INS Nilgiri and INS Vaghsheer commissioned

'PM Modi dedicated three frontline naval combatants to the nation on their commissioning.' The naval combatants – INS Surat, INS Nilgiri and INS Vaghsheer --were commissio

Read More

India’s First Ai-Driven Magazine Generator

Generate Your Custom Current Affairs Magazine using our AI in just 3 steps