Japan’s Nagoya University researchers led by Hiroano Miyatake, have probed the innate characteristics of dark matter existing in galaxies for 12 billion years ago. Being the first to report, Eureka Alert submits a study stating the definitive rules of cosmology are possibly different when approached through the early history of the universe.
Scientists, today, can see galaxies deep in space as they appeared billions of years ago with the help of the infinite speed of light, though examining dark matter was more difficult as it does not emit light.
In the case of a researcher, trying to explore the dark matter of a far-off galaxy, the surrounding space and time are distorted. As per Einstein’s theory of general relativity, they are distorted because of the gravitational pull of the dark matter and its galaxy.
The light travelling from the source through this distortion bends as well as the configuration of the galaxy is altered. The more the dark matter, the more distortion of the shape of the galaxy. This makes the scientist able to formulate the volume of dark matter from the foreground of the galaxy.
The deep portions of the universe are extremely subtle, making it more challenging for researchers to detect dark matter in distant galaxies. The farther the researchers explore, the more this technique lacks effectiveness. Therefore, it is important to detect a signal from the background galaxies.
Because of this drawback, scientists have so far investigated dark matter not older than 8 to 10 billion years ago. This leaves scientists with the mystery of the dark matter between present times and 13.7 billion years ago, from the inception of the universe.
To resolve this mystery, the research team led by Hiroano Miyatake used a different source of background light that released microwaves from the big bang itself. This investigation has conducted by the researchers of Nagoya University in partnership with the University of Tokyo, the National Astronomical Observatory of Japan and Princeton University.
The research team made use of the data from the Subaru Hyper Suprime Cam Survey to observe 1.5 million lens galaxies with the help of visible light, considered to have appeared 12 billion years ago.
The microwaves emitted from the cosmic microwave background (CWB), from the remnants of the Big Bang, were used to overcome the lack of galaxy light farther away. The team was now able to measure how dark matter distorts the microwaves surrounding the lens galaxies.
“Most researchers use source galaxies to measure dark matter distribution from the present to eight million years ago. However, we could look further back into the past because we used the more distant CMB to measure dark matter from almost the earliest moments of the universe”, described, Assistant Professor Yuichi Harikane of the Institute for the Cosmic Ray Research University of Tokyo.
The researchers were ascertained to have acquired large enough samples to detect the distribution of dark matter in the distant galaxy and combined this sample with the lensing distortions in CMB, the researchers were able to detect dark matter ageing to 12 billion years ago. This is believed to be around 1.7 billion years after the inception of the universe.
