Chandra offers new evidence for dark energy
Posted: Wed, May 19, 2004, 8:47 AM ET (1247 GMT)
Images from the orbiting Chandra X-Ray Observatory have provided astronomers with new evidence that a mysterious "dark energy" is causing the expansion of the universe to accelerate. Astronomers used Chandra to study 25 distant galaxy clusters at x-ray wavelengths, relying on the property of such clusters to have similar ratios of hot gas — which can be detected by Chandra — to the overall mass of the cluster, to measure the distance to each cluster. Astronomers found that the expansion of the universe first decelerated after the Big Bang, but began to accelerate about six billion years ago. That acceleration is thought to be caused by dark energy, an unexplained phenomenon that acts against gravity. Astronomers studying the Chandra data concluded that 75% of the universe is composed of dark energy, a similar fraction to other studies that relied on observations of distant supernovae.
Images from the orbiting Chandra X-Ray Observatory have provided astronomers with new evidence that a mysterious "dark energy" is causing the expansion of the universe to accelerate. Astronomers used Chandra to study 25 distant galaxy clusters at x-ray wavelengths, relying on the property of such clusters to have similar ratios of hot gas — which can be detected by Chandra — to the overall mass of the cluster, to measure the distance to each cluster. Astronomers found that the expansion of the universe first decelerated after the Big Bang, but began to accelerate about six billion years ago. That acceleration is thought to be caused by dark energy, an unexplained phenomenon that acts against gravity. Astronomers studying the Chandra data concluded that 75% of the universe is composed of dark energy, a similar fraction to other studies that relied on observations of distant supernovae.
Related Links:
| <<previous article | next article>> |
|
news in brief
|
|
Space Force adds Rocket Lab and Stoke Space to NSSL contract
Posted: Sun, Mar 30 9:19 AM ET (1319 GMT) |
|
news links
|
|
Thursday, April 3
How a kid from Pemberton helped lead a landmark commercial Moon landing
Australian Broadcasting Corporation — 6:00 am ET (1000 GMT) Eutelsat Begins OneWeb Services for the Aviation Market
ViaSatellite — 5:59 am ET (0959 GMT) Sierra Space demonstrates technology for Space Force satellite program
BizWest — 5:58 am ET (0958 GMT) Debrief: Vulcan On Deck
Aviation Week — 5:56 am ET (0956 GMT) ULA Targets April 9 For First Batch Of Amazon Kuiper Satellites
Aviation Week — 5:56 am ET (0956 GMT) |
