“CIBER” rocket exeriment sheds light on intergalactic space
Images captured by a NASA sounding rocket experiment have detected a surprisingly large amount of infrared light in the dark spaces between galaxies. This diffuse glow is as bright as all known galaxies combined and is thought to be from orphaned stars which were flung out of their home galaxies. NASA hosted a conference on Nov. 6, 2014 to provide details about this latest discovery – and the experiment that made it.Findings from the Cosmic Infrared Background Experiment (CIBER ) may redefine our understanding of galaxies. Instead of having a set boundary of stars – galaxies may stretch out to great-distances, forming a vast and possibly interconnected “sea” of stars.
The background infrared light that had been previously detected by NASA’s Spitzer Space Telescope but scientists have disagreed on whether it came from streams of stars stripped from their galaxies or from the first galaxies to form in the universe.
“We think stars are being scattered out into space during galaxy collisions,” said Michael Zemcov, lead author of a new paper describing the results from the rocket project and an astronomer at the California Institute of Technology (Caltech) and NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “While we have previously observed cases where stars are flung from galaxies in a tidal stream, our new measurement implies this process is widespread.”
CIBER used cameras launched aboard suborbital sounding rockets to capture wide-field images of the cosmic infrared background at two wavelengths shorter than those captured by Spitzer. These measurements can only be taken from space because Earth’s atmosphere is very bright in these wavelengths.
“It is wonderfully exciting for such a small NASA rocket to make such a huge discovery,” said Mike Garcia, program scientist from NASA Headquarters. “Sounding rockets are an important element in our balanced toolbox of missions from small to large.”
Once the cameras were launched into space they would then capture images for approximately seven minutes before transmitting data back to Earth. Scientists processing the images would then mask out bright stars and galaxies, carefully ruling out any light from more local sources including our own Milky Way Galaxy. What remained was a map showing fluctuations in the infrared background light, with blotches that are much brighter than individual galaxies. The brightness of these fluctuations allowed scientists to measure the total amount of background light.
The maps revealed an “excess” of light beyond what comes from galaxies. The data indicates that this infrared light has a blue spectrum, which means that it increases in brightness at shorter wavelengths. This is evidence that the light comes from previously unknown stars between galaxies. If the light had been coming from the first galaxies it would have given a redder spectrum of colors than what was observed.
“The light looks too bright and too blue to be coming from the first generation of galaxies,” said James Bock, principal investigator of the CIBER project from Caltech and JPL. “The simplest explanation, which best explains the measurements, is that many stars have been ripped from their galactic birthplace, and that the stripped stars emit on average about as much light as the galaxies themselves.”
Results of two of the four CIBER flights, which launched from White Sands Missile Range in New Mexico in 2010 and 2012, were published in the Friday, November 7 issue of the journal Science.
Jim Sharkey is a lab assistant, writer and general science enthusiast who grew up in Enid, Oklahoma, the hometown of Skylab and Shuttle astronaut Owen K. Garriott. As a young Star Trek fan he participated in the letter-writing campaign which resulted in the space shuttle prototype being named Enterprise. While his academic studies have ranged from psychology and archaeology to biology, he has never lost his passion for space exploration. Jim began blogging about science, science fiction and futurism in 2004. Jim resides in the San Francisco Bay area and has attended NASA Socials for the Mars Science Laboratory Curiosity rover landing and the NASA LADEE lunar orbiter launch.