Revolutionizing Cosmic Understanding: EPFL’s Groundbreaking Gravitational Lensing Technique to Measure Mass of Quasar Host Galaxies

A new study has found that researchers can now measure the mass of a galaxy hosting a quasar three times more accurately than with existing methods. This technique provides valuable insights into the evolution of galaxies throughout cosmic time, including the formation of black holes. The study was published in the prestigious journal Nature Astronomy, which suggests its importance.

The Gravitational Lensing Method

Gravitational lensing is a highly accurate method for obtaining mass estimates of galaxies in the distant universe, surpassing conventional techniques. This method involves using the bending of light from the background objects by foreground objects to calculate the mass of the lensing object. This method proves more reliable and offers a higher degree of accuracy compared to other methods because the measurement is not disturbed by the presence of conventional interferences.

Implementing gravitational lensing with quasars

One of the difficulties of measuring the weight of a quasar’s host galaxy is its intense brightness and distance. However, combining the gravitational lensing method with quasars offers a solution to this problem. The researchers took advantage of the natural alignment of a quasar and a foreground galaxy to create data that demonstrated the lensing effect. This alignment offered a rare opportunity to measure the mass of the lensing galaxy with unusual accuracy.

Results of the study

The study found that the method they used was three times more accurate than the previous methods used to weigh host galaxies. The measurements are highly significant since the mass measurement of quasar host galaxies provides insight into the early universe’s galaxy formation and black hole development. The precise measurement also allowed the researchers to see that black holes and their host galaxies adhered to a “co-evolution” process, indicating that galaxies and black holes grew and progressed simultaneously.

Future implications

The upcoming Euclid mission is expected to detect hundreds of lensing quasars, offering valuable insights into our place in the universe. The Euclid mission plans to measure the shapes and positions of billions of galaxies in the Universe, which could provide researchers with an extraordinary opportunity to study further galaxy formation and evolution.

In conclusion, the discovery and analysis of gravitational lensing events such as the SDSS J0919+2720 could provide crucial information on how supermassive black holes and their host galaxies evolve through cosmic times. The study’s lead author, Martin Millon, stated that this is the first time measurements of the masses of host galaxies have been so precise in the distant Universe, demonstrating how much the understanding of the universe is improving with such methods. Even though significant advancements have been made, grappling with the mysteries of the universe will need continued research and analysis to help further unravel them.

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