NASA’s sounding rocket CIBER has detected a surprising array of infra-red light in the supposed dark space between galaxies giving it a diffused cosmic glow as bright as all known galaxies combined.
NASA scientists say the glow is thought to be from orphaned stars flung out of galaxies, as galaxies may not have a set boundary of stars but instead stretch out to great distances into a vast and inter-connected sea of stars.
“We think stars are being scattered out into space during galaxy collisions. While we have previously observed cases where stars are flung from galaxies in a tidal stream, our new measurement implies this process is widespread,” explained Michael Zemcov, astronomer at the California Institute of Technology and NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.
The suborbital sounding rocket Cosmic Infrared Background Experiment (CIBER) captured wide-field pictures of the cosmic infra-red background at two infra-red wavelengths shorter than those seen by NASA’s Spitzer Space Telescope in the past.
“It is exciting for such a small NASA rocket to make such a huge discovery. Sounding rockets are an important element in our balanced toolbox of missions from small to large,” says scientist Mike Garcia from NASA headquarters in Washington, DC.
The data gathered by CIBER showed that the infra-red light has a blue spectrum, which means it increases in brightness at shorter wavelengths, which is enough of an evidence that light comes from a previously undetected stars between galaxies.
“The light looks too bright and too blue to be coming from the first generation of galaxies,” said James Bock of the CIBER project from Caltech.
Observations from the CIBER will settle a debate on whether this background infrared light in the universe, previously detected by Spitzer, comes from these streams of stripped stars too distant to be seen or from the first galaxies to form in the universe.
NASA said it need to conduct future experiments to test whether stray stars are indeed the source of the infrared cosmic glow or not.
The results are published in the journal Science.