Cosmic Necklace Reveals Secrets of Galaxy Birth ⚡ экспресс
Observations of the protocluster SPT2349-56 (12.8 billion light-years away) by the ALMA telescope showed that when massive galaxies merge, gas is ejected in the form of tidal tails, which break up into clumps — like beads on a string. Their density is comparable to the spiral arms of nearby galaxies, and the bright glow in the ionized carbon [CII] line indicates shock heating. Such tidal ejections could be the most important mechanism in the rapid assembly of giant galaxies in the early universe.
Three giant galaxies collide, and from the impact, gas flies away. But it does not disappear without a trace — it compresses into clumps resembling beads of a cosmic necklace, strung on an invisible thread spanning thousands of light-years. The light from these beads comes from atoms of carbon heated by shock waves — like the air in front of a supersonic jet, only on a galactic scale.
It's amazing that the gas remains colder than ice on Earth (minus 243°C), but glows due to intense heating from the collision. In this necklace, stars are born at a furious rate: thousands of new suns appear each year, while our Milky Way creates just a couple. Spectroscopy — breaking light into colors — allows us to peer into these processes, and observations are conducted at wavelengths where cold cosmic dust and gas shine.
Such a cataclysm is not chaos, but construction: from these beads, giant elliptical galaxies later form, the most massive in the Universe.
🎯 The gas 'beads' are heated only to -243°C — 20 degrees colder than Pluto's surface. But thanks to shock waves, they glow so brightly that they can be detected at a distance of billions of light-years.