Category Astronomy/Space

Credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt

It is known today that merging galaxies play a large role in the evolution of galaxies and the formation of elliptical galaxies in particular. However there are only a few merging systems close enough to be observed in depth. The pair of interacting galaxies seen here—known as NGC 3921 — is one of these systems.

NGC 3921—found in the constellation of Ursa Major (The Great Bear)—is an interacting pair of disk galaxies in the late stages of its merger. Observations show that both of the galaxies involved were about the same mass and collided about 700 million years ago. You can see clearly in this image the disturbed morphology, tails and loops characteristic of a post-merger.
The clash of galaxies caused a rush of star formati...

This sequence shows snapshots of a star’s density when two dark matter cores collide, where the x-axis is the plane of collision (only half the space is shown, but the remaining space can be obtained by symmetry). Although the final configuration is more compact and massive than the original, the star does not collapse into a black hole because it ejects some of its mass, slowing down its growth so that it remains stable. Credit: Brito, et al. ©2015 American Physical Society Read more at: http://phys.org/news/2015-09-dark-stars-oscillations.html#jCp

Large amounts of hidden mass inside stars might be composed of extremely lightweight hypothetical particles called axions, which are a primary dark matter candidate...

UBC researchers are proposing a new way to calculate distances in the cosmos using mysterious bursts of energy. The method allows researchers to position distant galaxies in 3 dimensions and map out the cosmos.
“We’ve introduced the idea of using these new phenomena to study cosmological objects in the universe,” said Kiyoshi Masui. “We believe we’ll be able to use these flashes to put together a picture of how galaxies are spread through space.”

Some unknown astrophysical phenomenon is causing these bursts of energy that appear as a short flashes of radio waves. While only 10 fast radio bursts have ever been recorded, scientists believe there could be thousands of them a day...

This simulation helps explain an odd light signal thought to be coming from a close-knit pair of merging black holes, PG 1302-102, located 3.5 billion light-years away. Credit: Columbia University

Entangled by gravity and destined to merge, 2 candidate black holes in a distant galaxy appear to be locked in an intricate dance. Researchers using data from NASA’s Galaxy Evolution Explorer (GALEX) and NASA’s Hubble Space Telescope have come up with the most compelling confirmation yet for the existence of these merging black holes and have found new details about their odd, cyclical light signal.

The candidate black hole duo, called PG 1302-102, was first identified earlier this year using ground-based telescopes...