When galaxies collide | EurekAlert! Science News

It was previously thought that collisions between galaxies would necessarily add to the activity of the massive black holes at their centers. However, researchers have performed the most accurate simulations of a range of collision scenarios and have found that some collisions can reduce the activity of their central black holes. The reason is that […]

Astronomers unmask cosmic eruptions in nearby galaxies

On April 15, 2020, a wave of X-rays and gamma rays lasting only a fraction of a second triggered detectors on NASA and European spacecraft. The event was a giant flare from a magnetar, a type of city-sized stellar remnant that boasts the strongest magnetic fields known. Credit: NASA’s Goddard Space Flight Center A brief […]

Galaxies hit single, doubles, and triple (growing black holes)

IMAGE: This pair of objects comes from a study of seven triple galaxy mergers. By using Chandra and other telescopes, astronomers determined what happened to the supermassive black holes at the centers of… view more  Credit: X-ray: NASA/CXC/Univ. of Michigan/A. Foord et al.; Optical: SDSS & NASA/STScI When three galaxies collide, what happens to the huge […]

Scientists just mapped 1 million new galaxies, in 300 hours

Astronomers in Australia have just mapped 83% of the observable universe, in just 300 hours. This new sky survey, which Australia’s national science agency (CSIRO) described in a statement as a “Google map of the universe” , marks the completion of a big test for the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope –- […]

The ultraviolet glow around some galaxies may come from runaway stars

Hot blue stars kicked out of their cradles may explain a mysterious ultraviolet glow that surrounds the disks of many spiral galaxies. A new computer simulation demonstrates that these runaway stars can populate the vast expanses beyond a galaxy’s visible disk (SN: 3/23/20). These distant regions have gas that is too warm and tenuous to […]

Five new dwarf galaxies detected around M63

Mosaic of direct and inverted images of low surface brightness dwarf galaxies in the vicinity of M 63. Credit: Karachentsev et al., 2020. Using an amateur 0.14-m aperture telescope, astronomers have observed a nearby spiral galaxy known as M63 (or NGC 5055). The observations identified the presence of five faint dwarf galaxies around M63 and […]

The Milky Way makes little galaxies bloom, then snuffs them out

If you’re a small galaxy and want to mint new stars, come to the Milky Way — but don’t get too close if you want a long-lasting star-making career. New observations with the Gaia space telescope show that our galaxy is both friend and foe to the lesser galaxies that revolve around it. Some 60 […]

The Grantecan finds the farthest black hole that belongs to a rare family of galaxies

IMAGE: Black-hole-powered galaxies called blazars are extremely rare. As matter falls toward the supermassive black hole at the galaxy’s center, some of it is accelerated outward at nearly the speed of… view more  Credit: M. Weiss/CfA Only a small fraction of the galaxies emits gamma rays, which is the most extreme form of light. Astronomers believe […]

Surprisingly mature galaxies in the early universe

Mosaic showing some of the galaxies observed by ALMA. The bright yellow regions are those where the most stars are forming (the ionised carbon (C+) line makes it possible to see the formation of stars obscured by dust). The second image from the left in the top row shows a triple merger. Credit: Michele Ginolfi/ALPINE […]

Why are galaxies different shapes?

Look into the night sky and you’ll glimpse the stars from hundreds of billions of galaxies. Some galaxies are swirling blue disks like our own Milky Way, others are red spheres or misshapen, clumpy messes or something in between. Why the different configurations? It turns out that a galaxy’s shape tells us something about the […]