Published
Scientists using data from NASA's Fermi Gamma-ray Space Telescope have measured all the starlight produced over 90 percent of the universe's history. The analysis, which examines the gamma-ray output of distant galaxies, estimates the formation rate of stars and provides a reference for future missions that will explore the still-murky early days of stellar evolution.
One of the main goals of the Fermi mission is to assess the extragalactic background light (EBL), a cosmic fog composed of all the ultraviolet, visible and infrared light stars have created over the universe's history. Because starlight continues to travel across the cosmos long after its sources have burned out, measuring the EBL allows astronomers to study stellar formation and evolution separately from the stars themselves.
The collision between a high-energy gamma ray and infrared light transforms the energy into a pair of particles, an electron and its antimatter counterpart, a positron. The same process occurs when medium-energy gamma rays interact with visible light, and low-energy gamma rays interact with ultraviolet light. Enough of these interactions occur over cosmic distances that the farther back scientists look, the more evident their effects become on gamma-ray sources, enabling a deep probe of the universe's stellar content.
The scientists examined gamma-ray signals from 739 blazars -- galaxies with monster black holes at their centers -- collected over nine years by Fermi's Large Area Telescope (LAT). The measurement quintuples the number of blazars used in an earlier Fermi EBL analysis published in 2012 and includes new calculations of how the EBL builds over time, revealing the peak of star formation around 10 billion years ago.
Music: "Inducing Waves" from Killer Tracks
Credit: NASA's Goddard Space Flight Center
Scott Wiessinger (USRA): Lead Producer
Jeanette Kazmierczak (University of Maryland College Park): Lead Science Writer
LK Ward (USRA): Narrator
Francis Reddy (University of Maryland College Park): Science Writer
Read more:
This video is public domain and may be downloaded at:
If you liked this video, subscribe to the NASA Goddard YouTube channel:
Follow NASA’s Goddard Space Flight Center
· Instagram
· Twitter
· Twitter
· Facebook:
· Flickr
One of the main goals of the Fermi mission is to assess the extragalactic background light (EBL), a cosmic fog composed of all the ultraviolet, visible and infrared light stars have created over the universe's history. Because starlight continues to travel across the cosmos long after its sources have burned out, measuring the EBL allows astronomers to study stellar formation and evolution separately from the stars themselves.
The collision between a high-energy gamma ray and infrared light transforms the energy into a pair of particles, an electron and its antimatter counterpart, a positron. The same process occurs when medium-energy gamma rays interact with visible light, and low-energy gamma rays interact with ultraviolet light. Enough of these interactions occur over cosmic distances that the farther back scientists look, the more evident their effects become on gamma-ray sources, enabling a deep probe of the universe's stellar content.
The scientists examined gamma-ray signals from 739 blazars -- galaxies with monster black holes at their centers -- collected over nine years by Fermi's Large Area Telescope (LAT). The measurement quintuples the number of blazars used in an earlier Fermi EBL analysis published in 2012 and includes new calculations of how the EBL builds over time, revealing the peak of star formation around 10 billion years ago.
Music: "Inducing Waves" from Killer Tracks
Credit: NASA's Goddard Space Flight Center
Scott Wiessinger (USRA): Lead Producer
Jeanette Kazmierczak (University of Maryland College Park): Lead Science Writer
LK Ward (USRA): Narrator
Francis Reddy (University of Maryland College Park): Science Writer
Read more:
This video is public domain and may be downloaded at:
If you liked this video, subscribe to the NASA Goddard YouTube channel:
Follow NASA’s Goddard Space Flight Center
· Facebook:
· Flickr
- Category
- Documentary
- Tags
- NASA
Be the first to comment
Up Next
Autoplay
-
02:50
NASA | Fermi Helps Scientists Study Gamma-ray Thunderstorms
-
07:43
NASA | MAVEN: NASA's Next Mission to Mars
-
02:24
NASA's Fermi Satellite Celebrates 10 Years of Discoveries
-
00:57
Multiple People Pushed To Stop The Challenger Mission #nasa #history #challenger
-
01:16
NASA’s Fermi Finds Record-breaking Binary Star
-
05:31
NASA | Fermi Sharpens its High-Energy View - 4K
-
00:48
NASA | MMS Mission Trailer
-
03:06
NASA's Laser Mission to Measure Trees
-
02:07
NASA's Fermi Links Cosmic Neutrino to Monster Black Hole
-
03:01
NASA | TRMM Mission Ends
-
05:04
Phil Keoghan On Tracing His Family’s History From Ireland To New Zealand
-
03:58
NASA’s Fermi Links Ghost Particle to Galaxy
-
03:03
NASA's Fermi Catches Gamma-ray Flashes from Tropical Storms
-
01:57
NASA | The MMS Mission's Unique Orbit
-
05:04
NASA's Fermi Mission Shows How Luck Favors the Prepared
-
02:54
NASA | Fermi Catches a 'Transformer' Pulsar
-
00:42
The Challenger's Mission Control Was In Denial #challenger #history #nasa
-
07:50
NASA’s OSIRIS-REx: Mission to Bennu
-
04:05
NASA | MMS Mission Overview
-
03:06
NASA | Fermi Detects First Gamma-ray Pulsar in Another Galaxy
-
01:50
Flying Over Hurricanes For New NASA Mission
-
02:00
NASA's Fermi Satellite Clocks a 'Cannonball' Pulsar
-
03:54
NASA | MAVEN Mission to Mars
-
01:59
NASA's Fermi Finds Vast 'Halo' Around Nearby Pulsar
Loading...