Scientists used a “galactic-sized”
New discovery, recently appeared in Astrophysical Journal Letter, From a project named “Gravitational Wave Nanonach Observatory” (NANOGrav) in the United States and Canada.
For 13 years, NANOGrav researchers have carefully studied the light emitted by dozens of pulsars throughout the Milky Way in an attempt to detect the “gravitational wave background.” This is what scientists call a stable gravitational radiation flux, and according to the theory, it constantly washes the earth. Joseph Simon, an astrophysicist at the University of Colorado at Boulder and lead author of the new paper, said the research team has not yet determined this goal, but it is closer than ever.
Simon, a postdoctoral researcher in the Department of Astrophysics and Planetary Sciences, said: “We found a strong signal in the data set.” “But we can’t say that this is the background of gravitational waves.”
In 2017, scientists won the Nobel Prize in Physics for the first direct detection of gravity waves in an experiment called the Laser Interferometer Gravitational Wave Observatory (LIGO). These waves were generated when two black holes collided with each other about 130 million light-years from the earth, and caused a cosmic impact, and spread to our own solar system.
That incident is equivalent to a crash-a violent and brief explosion. In contrast, the gravitational waves that Simon and his colleagues are looking for are more like a constant buzzing at a crowded cocktail party.
He added that detecting background noise would be a major scientific achievement, thus opening a new window for the operation of the universe. For example, these waves can provide scientists with new tools to study how the supermassive black holes in the centers of many galaxies merge over time.
“These tantalizing precursors in the background of gravitational waves suggest that supermassive black holes may indeed merge, and we are swaying in a sea of gravitation caused by the merger of supermassive black holes throughout the Milky Way,” said Julie Comerford, CU Boulder Celestial and planetary science with members of the NANOGrav team.
Simon will present his team’s findings at a virtual press conference at the 237th meeting of the American Astronomicalnomic Society on Monday.
Milky Way Lighthouse
Through their work on NANOGrav, Simon and Comerford are also very important in the international collaborative competition to find the background of gravity waves. Their project and two other countries from Europe and Australia formed a network called “International Pulsar Timing Array”.
Simon said, at least according to theory, merging galaxies and other cosmic events will produce stable gravitational waves. They are too small, Simon said, it may take years or even longer for a single wave to cross the earth. Therefore, other existing experiments cannot directly detect them.
Simon said: “Other observatories are searching for gravitational waves for a few seconds.” “We are looking for waves of the order of years or decades.”
He and his colleagues must be creative. The NANOGrav team uses telescopes on the ground not to look for gravitational waves but to observe pulsars. These collapsed stars are the beacon of the Milky Way. They spin incredibly fast, sending radiation streams to the earth in a scintillating pattern, and these radiation streams remain almost unchanged throughout the generations.
Simon explained that gravitational waves change the stable pattern of light from pulsars, pulling or squeezing the relative distance of these rays in space. In other words, scientists may be able to discover the background of gravitational waves just by monitoring changes in the timing of pulsars reaching the earth.
He said: “These pulsars spin as fast as a kitchen mixer.” “And we are studying their time deviation is only a few hundred nanoseconds.”
To discover this subtle signal, the NANOGrav team strives to observe as many pulsars as possible in the longest possible time. So far, the team has observed 45 pulsars in at least three years, and in some cases, they have been observing for more than ten years.
The hard work seems to be paying off. Simon and his colleagues reported in the latest study that they detected a unique signal in the data: Some common processes seem to be affecting the light emitted by many pulsars.
Simon said: “We went through each pulsar one by one. I think we all hope to find some unreliable pulsars.” “But then we went through everything and we said,’Oh my God, here There is something.'”
Researchers are still not sure what caused the signal. They will need to add more pulsars to their data set and observe them for a longer period of time to determine if they are actually gravitational wave backgrounds.
He said: “It would be a huge step to be able to detect the background of gravitational waves, but this is actually just the first step.” “The second step is to find out the causes of these fluctuations and discover that they can tell us about the universe. ”
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Astrophysical Journal Letter (2021). DOI: 10.3847 / 2041-8213 / abd401
Provided by the University of Colorado Boulder
Citation: The “galaxy-sized” observatory saw potential hints of gravitational waves (January 11, 2021), the gravitational force was January 11, 2021 from https://phys.org/news/2021-01-galaxy-sized -observatory-potential-hints-gravitational retrieved. html
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