Spiral Galaxy Current Affairs - 2019
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Scientists have discovered most ancient spiral galaxy known as A1689B11, recorded so far in the universe. It was detected using powerful technique that combines gravitational lensing with Near-infrared Integral Field Spectrograph (NIFS) on Gemini North telescope in Hawaii. Gravitational lenses are nature’s largest telescopes, created by massive clusters composed of thousands of galaxies and dark matter.
The A1689B11 galaxy was born 11 billion years ago and existed just 2.6 billion years after Big Bang, when universe was only one-fifth of its present age. It sits behind a massive cluster of galaxies that acts as lens, which scientists used to produce magnified images. The bending of cluster magnified light of galaxies behind it in manner similar to an ordinary lens, but on much larger scale. A1689B11 has very cool and thin disc, rotating calmly with surprisingly little turbulence unlike other galaxies of the same epoch.
Studying ancient spirals like A1689B11 can provide insights into early cosmos. It will help in unlocking mystery of how and when Hubble sequence emerges. Spiral galaxies are exceptionally rare in early universe and this discovery opens door to investigating how galaxies transition from highly chaotic, turbulent discs to tranquil, thin discs like those of our own Milky Way galaxy.