Spiral Galaxy Alaknanda:
Context:
Indian researchers from the National Centre for Radio Astrophysics (NCRA-TIFR), Pune, have discovered a massive spiral galaxy named Alaknanda that existed when the universe was just 1.5 billion years old.
It is a massive, well-defined spiral galaxy, which belongs to early Universe.
About Galaxy Alaknanda:
It was detected using NASA's James Webb Space Telescope (JWST) that is located approximately 12 billion light-years away
Unlike typical early-universe galaxies, which were chaotic and clumpy, Alaknanda possesses a well-defined grand design spiral structure with stable arms and a central bulge that is remarkably similar to the Milky Way
It is named after the Alaknanda River, a nod to its resemblance to the Milky Way (known as Mandakini in Hindi, the sister river to Alaknanda).
Significance of the findings:
Early galaxies were chaotic, clumpy, hot, and turbulent
Spiral structures take billions of years to form
Disk galaxies should not exist at high redshift
Alaknanda overturns this understanding by showing
A perfect spiral structure very early in the universe (just 1.5 billion years old)
A well-organized, rotation-dominated cold disk
Galaxy formation and maturation happened much faster than earlier models predicted.
Thus, it demands revision of the cosmic timeline of galaxy evolution.