Extreme Distance: GHZ2 holds the title of the farthest galaxy ever detected. Astronomers estimate it existed a mere 367 million years after the Big Bang, which is incredibly young by cosmic standards. The immense distance is evident from the galaxy's redshift of 12.117, which means its light has been stretched significantly towards the red end of the spectrum as the universe has expanded.
Early Formation: Given its vast distance, the light we see from GHZ2 has taken a very long time to reach us. In essence, we are seeing the galaxy as it was in its very early stages of development. This challenges our current understanding of how galaxies form so rapidly in such a young universe.
Surprisingly Massive: Despite its extreme youth, GHZ2 is estimated to be surprisingly massive, containing roughly four times more stars than our Milky Way galaxy. This is a puzzle for astronomers because prevailing theories suggest galaxies shouldn't have had enough time to accumulate so many stars at such an early epoch.
Possible Explanations for Mass: There are a couple of ideas to explain GHZ2's unexpected mass. One theory is that the galaxy resulted from a merger of several smaller ones, allowing it to accumulate a large stellar mass quickly. Another possibility is that GHZ2 resided in a particularly dense region of the early universe where dark matter was concentrated, which could have sped up its growth.
Confirmation and Ongoing Study: The initial detection of GHZ2 came from NASA's James Webb Space Telescope (JWST) during its GLASS survey. However, astronomers crave confirmation from other instruments. Subsequent observations using ALMA (Atacama Large Millimeter/submillimeter Array) helped solidify GHZ2's status as a real galaxy. Further study is ongoing to unravel the mysteries surrounding this record-breaking object and its role in challenging our understanding of early galaxy formation.