The data obtained from observations of the white dwarf and red giant system with NASA’s Swift and Chandra X-ray observatories throw another stone into the “standard candles” garden and suggest that astronomers will have to reconsider the methods used to calculate the rate of expansion of the universe.
I’m excited by the result. We fixed a completely new phenomenon, and this is very exciting.
-Tom McCarran, lead author of the study from the Texas Technical University (USA)
For decades, astronomers and astrophysicists have used certain supernovas to measure the velocity of the expansion of the universe. This is a type Ia that flares with the same brightness as a result of the accumulation of a critical mass by a white dwarf. Understanding the processes that lead to certain types of radiation from these systems is critical, and a new discovery can turn everything from head to foot.
Earlier it was thought that ultra-mild X-ray (SSXS) from supernova precursors of type Ia is the result of hydrogen fusion on the surface of a white dwarf, but new data have shown that it can also occur during accretion of matter.
In the past, ultra-mild X-ray radiation was bound only with nuclear fusion on the surface of white dwarfs, which captures material from a satellite-satellite, accumulates it, and eventually an explosion occurs. But what we discovered goes beyond the usual presentation. In our event, which received the designation ASASSN16-oh, radiation emanates from an area much smaller than the surface of a white dwarf, and we have strong arguments against any explosion as a source of SSXS.
-Tom McCarron
The discovery was made during the observation of the system of the white dwarf and the red giant star living in the Small Magellanic Cloud, the galactic satellite of the Milky Way. Scientists believe that the white dwarf created an extremely large radiating disc around its companion material around itself. The flow rate of the substance through the disk is unstable, and when it starts to flow faster, the system’s brightness rises.
What we have recorded is an episode of ultramodern radiation, but without any signs that could be related to nuclear fusion. Instead, we see a hot emission from a disk that transports material from a companion star to a white dwarf. At the same time, the transfer of mass occurs at a higher pace than in any system that we have seen earlier.
-Tom McCarran
So there are two ways in which you can get SSXS: nuclear synthesis and accretion. This conclusion is interesting in itself, but the most important part of it is that it can change the methods that astrophysicists use to measure the velocity of the expansion of the universe.
These systems are the basis for determining the expansion of the universe. To determine it more precisely than it is available now, it’s necessary to understand the origin of the supernova type Ia, and opening a new way of creating ultra-mild X-ray radiation will make a rethink of the current approach today.
-Tom McCarran
Astronomers are reconsidering the method of determining universe expansion rate
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