For the first time, astronomers must have heard ‘we’, the background of the universe


Based on what we know about gravitational waves, the universe must be filled with them. Every colliding pair of black holes or neutron stars, every core-collapse supernova – even the Big Bang itself – should have sent ringing rings into spacetime.

After all this time, these waves will seem weak and hard, but they are all predicted to create an echo ‘we’ that refers to our universe as the gravitational wave background. And we may have caught the first sign of it.

You can think of the background of the gravitational wave as the ring left behind large-scale events in the history of our universe – possibly invaluable to our understanding of the universe but incredibly difficult to detect.

“It’s incredibly exciting to see such a strong signal from the data,” said astronomer Joseph Simon of the University of Colorado Boulder and the Nanjov Collaboration.

“However, because the gravitational-wave signals we have been searching for the entire duration of our observations, we need to understand our noise carefully. This leaves us in a very interesting place, where we can detect some known noise sources. Can rule strongly, but we can’t say yet whether the signal is actually from gravitational waves. We’ll need more data for that. “

Nevertheless, the scientific community is excited. More than 80 papers have appeared, citing research, as the team’s preprint was posted to XX in September of last year.

International teams are working hard, analyzing the data to confirm or confirm the team’s results. If it turns out that the signal is real, it can open a whole new phase of gravitational wave astronomy – or reveal to us entirely new astronomical phenomena.

The signal comes from the observation of a type of dead star called a pulsar. These are neutron stars that are oriented in such a way that they flash the beams of radio waves from their poles as they spin at a millisecond speed compared to a kitchen blender.

These flashes are incredibly well timed, meaning that Pulsars are possibly the most useful stars in the universe. To examine the interstellar medium and study gravity, their time shifts can be used for navigation. And, since the discovery of gravitational waves, astronomers have been using them to search for them, too.

This is because gravitational waves replace spacetime, because they theoretically change – just much less – the time of radio pulses delivered by the pulsar.

” [gravitational wave] The background between the pulsar and the Earth lengthens and shrinks, allowing signals from the pulsar to come a little later (stretch) or earlier (shrink), otherwise if gravitational waves were not there, it would have been, “Astronomers of Swinburne University Scientists Ryan Shannon Technology and the Ozgrave Collaboration, who were not involved in the research, explained ScienceArt.

A single pulsar with irregular beats would not mean much. But if the entire flock of pulsars exhibited a correlated pattern of time variation, that might constitute evidence of a gravitational wave background.

Such a collection of pulsars is known as the pulsar time table, and is exactly what the Nanjrao team is observing 45 of the most stable millisecond pulsars in the Milky Way.

They have not quite detected the signal that would confirm the background of the gravitational wave.

But they have detected something – a “normal noise” signal, which Shannon explained, varies from pulsar to pulsar, but exhibits similar characteristics each time. Simon said that these deviations led to changes of a few hundred nanoseconds over 13 years.

There are other things that can produce this signal. For example, a pulsar timing array needs to be analyzed from a frame of reference that is not fast, which means that any data needs to be transposed to the center of the solar system rather than the Earth, which Known as barrientre.

If the barrientre is not calculated correctly – it is a tricky thing, because it is the center of mass of all moving objects in the solar system – then you may get an incorrect signal. Last year, the NANOGrav team announced that they counted the solar system barrientre within 100 meters (328 ft).

There is still a chance that this discrepancy may be the source of the signal they find, and more work needs to be done to work it out.

Because if the signal is actually from some resonant gravitational wave humming, it would be a very big thing, because the source of these background gravitational waves is likely to have supermassive black holes (SMBHs).

Since gravitational waves show us phenomena that we cannot detect electromagnetically – such as black hole collisions – it can help solve such condooms as the ultimate parsec problem, which suggests that supremacives Black holes may not be able to merge, and help us better understand galactic growth and development.

Further down the road, we may also be able to detect the gravitational waves generated just after the Big Bang, giving us a unique window into the early universe.

Obviously, we have to do a lot before we get to that point.

“This is a possible first step towards detecting the Nanohartz frequency gravitational wave,” Shannon said. “I will warn the public and scientists not to give more information about the results. In the next year or two I think the evidence will come out as to the nature of the signal.”

Other teams are also working on using pulsar timing arrays to detect gravitational waves. Ozagra Parkes is part of the Pulsar Timing Array, which will soon release an analysis of its 14-year dataset. The European Pulsar Timing Array is also difficult to operate. The result of NANOGrav will only increase the excitement and anticipation that something will be found there.

“It’s incredibly exciting to see such a strong signal from our data, but the most exciting things for me are the next steps,” Simon told ScienceArt.

“While we still have to move forward to get a definitive identity, which is only the first step. In addition, we have the opportunity to pinpoint the source of the GWB, and furthermore, we realize that they are about us Can tell. Universe. “

The team’s research has been published in The Astrophysical Journal Letters.

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