Why in News?
An international team of astronomers has discovered 31 ancient quasars, including the two oldest ever observed in cosmic history, using the European Space Agency's (ESA) Euclid space telescope.
What is a Quasar?
- Luminous Galatic Cores: Quasars (quasi-stellar radio sources) are the intensely bright centers of distant galaxies.
- Black Hole Engines: They are powered by supermassive black holes fiercely devouring enormous amounts of surrounding gas and dust.
- Extreme Energy: As matter spirals into the black hole, friction and gravity heat it to millions of degrees, releasing energy that can outshine its entire host galaxy by 100 to 1,000 times.
Specifications of the Oldest Pair
- Designations: The two record-breakers are designated as EUCL J172902.75+641018.1 and EUCL J125308.55+705432.3.
- Redshift Values: They possess extreme cosmic redshifts of 7.77 and 7.69, respectively (higher redshift means older and more distant).
- Extreme Luminosity: Both bodies shine with the collective power of one trillion suns.
- Distance: Their primordial light travelled across the expanding cosmos for more than 13 billion light-years to reach Earth.
The "Cosmic Quandary" (The Big Puzzle)
- Impossible Speed: These ancient black holes weigh hundreds of millions to billions of times the mass of our sun.
- Growth Anomaly: Scientists do not currently understand how such "monsters" grew so massive, so fast, right at the dawn of the universe.
- Epoch of Reionisation: They existed during the crucial cosmic phase when the first stars and galaxies lit up, burning through the dark, neutral hydrogen fog filling the early universe.
How They Were Found?
- Overcoming Dust Haze: Looking from ground telescopes is difficult because the universe's expansion stretches quasar light from UV into near-infrared wavelengths, which normally get drowned out by Earth's atmosphere.
- Space-Based Efficiency: The space telescope Euclid, operating 1.5 million kilometers from Earth, bypassed this infrared haze to scan large fields of space cleanly.
- Advanced Code: Astronomers used smart machine-learning algorithms to filter out tens of millions of closer stellar "imposters" to accurately locate the real quasars.
Download Pdf
