三级aa视频在线观看-三级国产-三级国产精品一区二区-三级国产三级在线-三级国产在线

Global EditionASIA 中文雙語Fran?ais
World
Home / World / Kaleidoscope

Astronomers identify two of Milky Way's earliest building blocks: study

Xinhua | Updated: 2024-03-21 19:28
Share
Share - WeChat

BERLIN -- Research scientists at the German Max Planck Institute for Astronomy have identified "good candidates for some of the earliest ancestors of our Milky Way." The results have been published in the Astrophysical Journal.

Named "Shakti" and "Shiva," the two structures appear to be the remnants of two galaxies that merged with an early version of the Milky Way between 12 and 13 billion years ago, thus contributing to its initial growth.

The institute said in a statement on Thursday that the discovery was the "astronomical equivalent of archeologists identifying traces of an initial settlement that grew into a large present-day city."

So far, it is impossible to identify which stars came from which predecessor galaxy after a collision of galaxies. However, most stars retain basic properties, which are "directly linked to the speed and direction of the galaxy in which they originated," the institute said.

Using "basic physics," the researchers found large groups of stars with similar, unusual values for energy and angular momentum—the momentum associated with orbital motion or rotation—that indicated a possible merger remnant. The very low metal content of the stars was an "additional pointer" that suggested they already existed at the time of the early version of the Milky Way.

The Max Planck Institute said that thanks to the European Space Agency's astrometry satellite Gaia, "large and high-quality data sets" were available. Launched in 2013, the satellite "revolutionized studies of the dynamics of stars" in the Milky Way, producing an increasingly accurate data set including positions, changes in position and distances for almost 1.5 billion stars.

The researchers now identified the two structures by combining data from the Gaia satellite with stellar spectra from the Sloan Digital Sky Survey, which provide detailed information about the stars' chemical composition.

New surveys are promising to deliver more relevant data. Both spectra and precise distances should "enable astronomers to make a firm decision on whether or not Shakti and Shiva are indeed a glimpse of our home galaxy's earliest prehistory," the institute said.

Most Viewed in 24 Hours
Top
BACK TO THE TOP
English
Copyright 1995 - . All rights reserved. The content (including but not limited to text, photo, multimedia information, etc) published in this site belongs to China Daily Information Co (CDIC). Without written authorization from CDIC, such content shall not be republished or used in any form. Note: Browsers with 1024*768 or higher resolution are suggested for this site.
License for publishing multimedia online 0108263

Registration Number: 130349
FOLLOW US
主站蜘蛛池模板: 在线观看视频日韩 | 国产精品视频二区不卡 | 一级毛片国产 | 一级特黄aaa大片大全 | 亚洲一区二区三区日本久久九 | 放荡女同老师和女同学生 | 日韩欧美在线中文字幕 | 成人亚洲欧美日韩在线 | 日韩3区 | 亚洲第一成人天堂第一 | 中中文字幕亚州无线码 | 久草资源站在线 | 真实国语对白视频播放 | 国产一级特黄aa大片在线 | 男女一级特黄a大片 | 尤物视频www | 在线视频中文字幕乱人伦 | 久久性 | 黄色免费影视 | 日韩女人毛片在线播放 | 免费看黄色的视频 | 国产成人污污网站在线观看 | 国产美女无遮挡免费网站 | 韩国理论毛片a级 | 国产成人免费网站在线观看 | 久久婷婷午色综合夜啪 | 色婷婷影院 | 欧美黑人性大免费高清视频 | 色屁屁www影院免费观看入口 | 日本一级毛片2021免费 | 成人在线亚洲 | 成 人 免费观看网站 | 亚洲永久视频 | 日韩高清一区 | 国产大片好看免费播放 | 日本做爰免费大片视频 | 久久视频这里只精品3国产 久久视热这只是精品222 | 91久久精一区二区三区大全 | 国产91长腿美女在线观看 | 欧美一级级a在线观看 | 香蕉视频免费播放 |