 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
| . |  |
. |
 by Staff Writers Tokyo, Japan (SPX) Dec 20, 2019
A distant galaxy more massive than our Milky Way - with more than a trillion stars - has revealed that the 'cores' of massive galaxies in the Universe had formed already 1.5 billion years after the Big Bang, about 1 billion years earlier than previous measurements revealed. "If we point a telescope to the sky and take a deep image, we can see so many galaxies out there," said Masayuki Tanaka, paper author and associate professor of astronomical science in the Graduate University for Advanced Studies and the National Astronomical Observatory of Japan. "But our understanding of how these galaxies form and grow is still quite limited - especially when it comes to massive galaxies." Galaxies are broadly categorized as dead or alive: dead galaxies are no longer forming stars, while living galaxies are still bright with star formation activity. A 'quenching' galaxy is a galaxy in the process of dying - meaning its star formation is significantly suppressed. Quenching galaxies are not as bright as fully alive galaxies, but they're not as dark as dead galaxies. Researchers use this spectrum of brightness as the first line of identification when observing the Universe. The researchers used the telescopes at the W.M. Keck Observatory in Hawaii to observe a quenching galaxy in what is called the Subaru/XMM-Newton Deep Field. This region of the sky has been closely observed by several telescopes, producing a wealth of data for scientists to study. Tanaka and his team used an instrument called MOSFIRE on the Keck I telescope to obtain measurements of the galaxy. They obtained a two-micron measurement in the near-infrared spectrum, which the human eye cannot see, but it confirmed that the light from the galaxy was emitted just 1.5 billion years after the Big Bang. The team also confirmed that the galaxy's star formation was suppressed. "The suppressed star formation tells you that a galaxy is dying, sadly, but that is exactly the kind of galaxy we want to study in detail to understand why quenching occurs," said Francesco Valentino, a co-author of the paper and an assistant professor at the Cosmic Dawn Center in Copenhagen. According to Valentino, astronomers believe that massive galaxies are the first to die in the history of the Universe and that they hold the key to understanding why quenching occurs in the first place. "We also found that the 'cores' of massive galaxies today seem to be fully formed in the early Universe," Tanaka said. How stars move within a galaxy depends on how much mass that object contains. Tanaka and his team found that the stars in the distant galaxy seem to move just as quickly as those closer to home. "The previous measurement of this kind was made when the Universe was 2.5 billion years old. We pushed the record up to 1.5 billion years and found, to our surprise, that the core was already pretty mature." The researchers are continuing to investigate how massive galaxies form and how they die in the early Universe, and they are searching for more massive quenching galaxies in the far distant Universe that may shed light on earlier phases of the process. "When did the first dead galaxy appear in the Universe?" Tanaka asked. "This is a very interesting question for us to address. To do so, we will continue to observe the deep sky with the largest telescopes and expand our search as more advanced facilities become available." Researchers published their analysis on November 6, 2019 in The Astrophysical Journal Letters, a journal of the American Astronomical Society.
Scientists inch closer than ever to signal from cosmic dawn Providence RI (SPX) Nov 27, 2019 Around 12 billion years ago, the universe emerged from a great cosmic dark age as the first stars and galaxies lit up. With a new analysis of data collected by the Murchison Widefield Array (MWA) radio telescope, scientists are now closer than ever to detecting the ultra-faint signature of this turning point in cosmic history. In a paper on the preprint site ArXiv and soon to be published in The Astrophysical Journal, researchers present the first analysis of data from a new configuration of the M ... read more
|
|||||||||||||
|
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |
del.icio.us
Digg
Reddit
Google
