How a distant galaxy gave a glimpse of Milky Way in its infancy

Sub : Sci

Sec : Space sector

Context:

NASA’s James Webb Space Telescope (JWST) has observed a distant galaxy named Firefly Sparkle, located around 13 billion light-years away.
This galaxy, named for its star clusters that resemble bioluminescent fireflies, offers a glimpse into what the Milky Way might have looked like in its early stages.
The galaxy is an infant, formed within the first few hundred million years after the Big Bang.

Significance of Firefly Sparkle:

Firefly Sparkle is observed as it was formed just a few hundred million years after the Big Bang (~13.8 billion years ago).
Its distance of 13 billion light-years means the light from this galaxy took 13 billion years to reach the JWST, offering a snapshot of the universe in its infancy.
Firefly Sparkle is still in the process of assembly, with star formation occurring at an early stage.
Researchers believe it formed about 100-400 million years before the stage observed by the JWST.

Key Characteristics of Firefly Sparkle:

The galaxy has a mass equivalent to 10 million stars the size of our Sun and contains 10 densely packed star clusters. These clusters are embedded within a diffuse arc of stars, spanning about 1,000 light-years
Firefly Sparkle is accompanied by two smaller galaxies, Firefly-Best Friend and Firefly-New Best Friend, indicating its early-stage formation.

Insights into the Milky Way’s formation:

Astronomers highlighted that the Milky Way likely began forming around the same time as Firefly Sparkle.
This galaxy serves as a direct observation of what the Milky Way might have looked like in its infancy, at 10,000 times less mass than its current state.
Over billions of years, the Milky Way grew and evolved through mergers with other galaxies and continued star formation.

Role of Gravitational Lensing:

Firefly Sparkle is so far away and small that it would have been impossible to observe directly. However, a cluster of galaxies between the JWST and Firefly Sparkle caused a phenomenon called gravitational lensing.
Gravitational lensing distorts spacetime, bending and amplifying the light coming from distant objects. In this case, the light from Firefly Sparkle was magnified 16-26 times, allowing astronomers to observe the galaxy in exceptional detail.
The galaxy cluster acted as a magnifying glass, making it possible to study the distant Firefly Sparkle despite its tiny size and immense distance from Earth.

Gravitational Lensing:

Gravitational lensing occurs when a large amount of matter, like a massive galaxy, galaxy cluster, or black hole, creates a gravitational field that bends and magnifies the light from objects located behind it.