Cosmic Neon Sign: Gas Glows Brighter Than Stars ⚡ экспресс
With the James Webb Telescope, astronomers studied a galaxy at redshift 5.124, whose spectrum is dominated by the glow of scorching gas (nebular continuum) — over 95% of the light. This gas is heated to 53,000 K and is very dense, explaining a peculiar 'Balmer jump' — a sharp brightness drop. Nearby lurks a mysterious metal-free satellite galaxy, likely made of the ashes of the first stars (Population III). The discovery hints that such massive primordial stars might have lit up the early Universe brighter than we thought.
A cosmic neon sign lit up in an incredibly distant galaxy: almost all its light comes from hot gas, and the stars are lost in this glow. The James Webb telescope recorded that the gas—a mix of hydrogen and helium—is so heated that it glows on its own.
The secret of such brightness is the first stars of the Universe. A faint satellite galaxy was noticed nearby with no traces of heavy elements: it is likely a clump of remnants of stars born right after the Big Bang. These giants, hundreds of times more massive than the Sun, faded long ago, but their energy, like an invisible current, heats the gas and makes it shine. Johann Balmer back in the 19th century described a special jump in hydrogen's glow—today it serves as a thermometer for distant galaxies.
Without Webb, such a discovery would have been impossible. It peers into the era when the first galaxies were forming, and helps understand how the expansion of the Universe changed the light, discovered by Edwin Hubble.
🎯 The Balmer jump works like a cosmic thermometer: by its magnitude astronomers determine gas temperature with an accuracy of a few thousand degrees.