Archive for the ‘cosmology’ category: Page 353
Aug 29, 2018
Ancient ‘Monster Galaxy’ Is Forming Stars a Thousand Times Faster Than the Milky Way
Posted by Genevieve Klien in category: cosmology
Chile’s Atacama Large Millimeter/submillimeter Array (ALMA) has observed a galaxy that looks nothing like what researchers expected. It’s forming stars at an absolutely incredible rate.
The “Monster Galaxy”, also known as COSMOS-AzTEC-1, formed just 2 billion years after the Big Bang, and it turns more than a thousand Suns worth of gas into stars each year. Scientists still don’t understand these early galaxies very well, but now they have some new information that can shed light on why they form stars so blisteringly fast.
Aug 28, 2018
Scientists may have discovered the very first ‘ghost’ black hole from a different universe
Posted by Genevieve Klien in category: cosmology
It’s common knowledge that, because of the speed at which light travels, we can see things in space that aren’t even there anymore. If we peer at a distant galaxy we’re really only seeing what the objects within it looked like when the light itself was beaming in our direction. If the galaxy is a thousand light-years away, we’re seeing what the galaxy looked like a thousand years ago.
Now, researchers believe that they may be able to use a similar technique to search for black holes that don’t exist anymore. The only difference is that the black holes aren’t just from long ago, they’re from an entirely different version of the universe. Woah.
A research team comprised of scientists from Oxford University, the University of Warsaw, and the New York Maritime College, believe they have evidence that points to the leftovers of a black hole that existed in a universe that preceded the one we’re currently living in. However, rather than visible light, the black holes leave behind what is known as cosmic microwave background radiation, or (CMB).
Aug 27, 2018
To Test Einstein’s Equations, Poke a Black Hole
Posted by Genevieve Klien in categories: cosmology, information science, mathematics
Researchers make significant progress toward proving a critical mathematical test of the theory of general relativity.
- By Kevin Hartnett, Quanta Magazine on August 27, 2018
Aug 27, 2018
The Physics of Falling Into a Black Hole
Posted by Genevieve Klien in categories: cosmology, physics
This week, newspapers reported that a man had fallen into an art installation consisting of an 8-foot-deep circular hole painted black. It’s kinda not his fault.
Aug 27, 2018
What Is Nothing? Martin Rees Q&A
Posted by Genevieve Klien in categories: cosmology, physics
This article was originally published at The Conversation. The publication contributed the article to Space.com’s Expert Voices: Op-Ed & Insights.
Philosophers have debated the nature of “nothing” for thousands of years, but what has modern science got to say about it? In an interview with The Conversation, Martin Rees, Astronomer Royal and Emeritus Professor of Cosmology and Astrophysics at the University of Cambridge, explains that when physicists talk about nothing, they mean empty space (vacuum). This may sound straightforward, but experiments show that empty space isn’t really empty – there’s a mysterious energy latent in it which can tell us something about the fate of the universe.
Rees was interviewed for The Conversation’s Anthill podcast on Nothing. This Q&A is based on an edited transcript of that interview.
Aug 22, 2018
Physicists Think They’ve Spotted the Ghosts of Black Holes from Another Universe
Posted by Genevieve Klien in categories: cosmology, physics
Weird patches of the sky where the cosmic microwave background radiation looks funny could be signs of long-dead universes, physicist Roger Penrose said.
Aug 18, 2018
A supermassive black hole used its powerful gravity to rip apart a star that wandered too close to the massive monster
Posted by Michael Lance in category: cosmology
Astronomers used radio & infrared telescopes to image the distant eruption of this cosmic duel. Details: https://go.nasa.gov/2JMkZWF
Aug 17, 2018
The Universe’s Oldest Galaxies Could Be Right in the Milky Way’s Backyard
Posted by Genevieve Klien in category: cosmology
The Universe’s earliest epochs appear to be written into the small dwarf galaxies orbiting our own galactic home, the Milky Way.
A team of researchers studying dark matter noticed a strange trend in the brightness of the satellite galaxies around the Milky Way. There seem to be two classes of these orbiting dwarf galaxies—dim ones and bright ones—with few in the middle range. The researchers propose that this kink, when viewed on a graph, could be explained by a period early on in the Universe’s history called the re-ionization era.
Aug 17, 2018
Another way for stellar-mass black holes to grow larger
Posted by Genevieve Klien in categories: cosmology, physics
A trio of researchers with The University of Hong Kong, Academia Sinica Institute of Astronomy and Astrophysics in Taiwan and Northwestern University in the U.S., has come up with an alternative theory to explain how some stellar-mass black holes can grow bigger than others. In their paper published in The Astrophysical Journal Letters, Shu-Xu Yi, K.S. Cheng and Ronald Taam describe their theory and how it might work.
Since the initial detection of gravitational waves three years ago, five more detections have been observed—and five of the total have been traced back to emissions created by two stellar-mass black holes merging. The sixth was attributed to neutron stars merging. As part of their studies of such detections, space researchers have been surprised by the size of the stellar-mass black holes producing the gravity waves—they were bigger than other stellar-mass black holes. Their larger size has thus far been explained by the theory that they grew larger because they began their lives as stars that contained very small amounts of metal—stars with traces of metals would retain most of their mass because they produce weaker solar winds. In this new effort, the researchers suggest another possible way for stellar-mass black holes to grow larger than normal.
The new theory starts out by noting that some supermassive black holes at the hearts of galaxies are surrounded by a disk of gas and dust. In such galaxies, there are often stars lying just outside the disk—stars that could evolve to become stellar-mass black holes. The researchers suggest that it is possible that sometimes, pairs of these stars wind up in the disk as they evolve into black holes. Such stellar-mass black holes would pull in material from the disk, causing them to grow larger. The researchers note that if such a scenario were to play out, it is also possible that the two merging stars could wind up with a synchronized spin resulting in a stellar-mass black hole that produces more gravity waves than if the spins had not been synchronized, making them easier for researchers to spot.