Glowing dust galaxies are hiding some secret companions in a distant universe. The University of Sussex researchers found that the glow of heated dust reaching our planet is frequently due to three or four galaxies instead of a single one, as scientists had previously assumed.
The study applied a statistical method to data from the Herschel Space Observatory to solve one of astrophysics’ great conundrums, the United Press International reports. Lead author Dr Jillian Scudder said that the result has been very interesting.
“This is a really interesting result because when we assumed that one galaxy had to be responsible for all of the dust emission, it implied that the galaxy must be forming a tremendous number of new stars,” Scudder said. “Forming that number of stars in a galaxy so early in the Universe is quite hard to explain. By finding that each galaxy is actually two or three galaxies, we’ve dropped the number of stars these galaxies have to be producing by a third.”
The glowing dust galaxies were revealed using far-infrared observations with relatively low resolution, Science Daily reported. The task of determining the illumination source of bright intergalactic dust is complicated by two main issues. The first is a resolution problem.
Each object detected by Herschel is blurred over an area about 26 times as large as the entire Milky Way. But if you look at the same patch of sky with better resolution, a number of galaxies appear, not just one.
The second problem is when astronomers take a closer look and see multiple glowing dust galaxies where there previously appeared to be one, they tend to credit the galaxy closest to the glowing dust and the sole source of light.
The latest statistical model suggests a single galaxy is likely only the source of illumination when it is positioned directly in the center of a gas blob. In all other instances, the analysis suggests, distant glowing gas is being heated by the radiation of several galaxies.
The study looked at a sample of 360 objects detected at 250 micron by Herschel within the COSMOS field and revealed that the sample is almost entirely made up of at least two dust-bright galaxies hiding within the low-resolution images from Herschel.
Space said that the glowing dust galaxies are a revelation made possible by a new statistical algorithm that can determine which galaxies are illuminating the large blobs of hot gas imaged by Earth-bound observatories. Researchers detailed the algorithm and its implications in a new paper, set for publication in the journal Monthly Notices of the Royal Astronomical Society.