NASAさんのインスタグラム写真 - (NASAInstagram)「Using the unique capabilities of @NASAHubble, a team of astronomers has discovered the most energetic outflows ever witnessed in the universe. They emanate from quasars and tear across interstellar space like tsunamis, wreaking havoc on the galaxies in which the quasars live. Quasars are extremely remote celestial objects, emitting exceptionally large amounts of energy. Quasars contain supermassive black holes fueled by infalling matter that can shine 1,000 times brighter than their host galaxies of hundreds of billions of stars. As the black hole devours matter, hot gas encircles it and emits intense radiation, creating the quasar. Winds, driven by blistering radiation pressure from the vicinity of the black hole, push material away from the galaxy's center. These outflows accelerate to breathtaking velocities that are a few percent of the speed of light. "No other phenomena carries more mechanical energy. Over the lifetime of 10 million years, these outflows produce a million times more energy than a gamma-ray burst," explained principal investigator Nahum Arav of Virginia Tech in Blacksburg, Virginia. "The winds are pushing hundreds of solar masses of material each year. The amount of mechanical energy that these outflows carry is up to several hundreds of times higher than the luminosity of the entire Milky Way galaxy." The quasar winds snowplow across the galaxy's disk. Material that otherwise would have formed new stars is violently swept from the galaxy, causing star birth to cease. Radiation pushes the gas and dust to far greater distances than scientists previously thought, creating a galaxy-wide event. As this cosmic tsunami slams into interstellar material, the temperature at the shock front spikes to billions of degrees, where material glows largely in X-rays, but also widely across the light spectrum. Anyone witnessing this event would see a brilliant celestial display. "You'll get lots of radiation first in X-rays and gamma rays, and afterwards it will percolate to visible and infrared light," said Arav. "You'd get a huge light show—like Christmas trees all over the galaxy." Credit: NASA, ESA and J. Olmsted (STScI)」3月22日 10時19分