Sunday, October 22, 2017

Across The Universe, Cont. - Colliding Neutron Stars Produce Gamma Ray Bursts And Gravitational Waves


(click on image to enlarge)



From NASA, October 16, 2017: On August 17, 2017, the Laser Interferometer Gravitational-wave Observatory detected gravitational waves from a neutron star collision. Within 12 hours, observatories had identified the source of the event within the galaxy NGC 4993, shown in this Hubble Space Telescope image, and located an associated stellar flare called a kilonova (box). Inset: Hubble observed the kilonova fade over the course of six days. Credits: NASA and ESA

The significance of this observation, briefly:
In August, for the first time ever, scientists witnessed the electromagnetic lightning and gravitational gusts from the stormy collision of two neutron stars in a distant galaxy. The cosmic cataclysm created a “kilonova” — a phenomenon that had never been seen before — and the observations by both traditional telescopes and gravitational wave detectors heralded a new era for science. In the years to come, astrophysicists will use two “messengers” to understand the universe: electromagnetism and gravity. 
The effort to capture the event's fleeting signals involved three gravitational wave detectors, more than five dozen telescopes on every continent including Antarctica, seven space-based observatories, and, according to one estimate, 15 percent of the world's astronomers. It yielded 20 scientific papers published in three separate journals and answered a broad array of questions about the cosmos: What happens when neutron stars collide? How are precious elements like gold produced? Where do some bursts of high-energy gamma rays originate? 
Those discoveries are just the beginning: “This is opening a new brand of research and science,” Eleonora Troja, an astrophysicist at NASA's Goddard Space Flight Center and the University of Maryland, said Tuesday.
The article continues with a discussion of how this detection will change the course of astronomy.

More here from NASA (including more images of the neutron star collision).