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Archive for the ‘cosmology’ category: Page 298

Sep 24, 2019

China’s Taiji-1 on a gravity wave mission

Posted by in categories: cosmology, physics

CAS has announced the research program “Taiji” that will study gravitational waves from the merging of binary black holes and other celestial bodies.

Unlike the LIGO research conducted from a ground-based observatory, Taiji will conduct space-based detection on the gravitational waves with lower frequencies to observe celestial bodies with greater mass or located farther away in the universe, said Wu Yueliang, chief scientist of the Taiji program and an academician of CAS.

However, the gravitational wave signals from those celestial bodies are extremely weak, posing great challenges for detection. Scientists need to break through the limit of current precise measurement and control technology, Wu said.

Sep 23, 2019

Theory proposes that LIGO/Virgo black holes originate from a first order phase transition

Posted by in categories: cosmology, particle physics

A few years ago, the LIGO/Virgo collaboration detected gravitational waves arising from a binary black hole merger using the two detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO). This eventually led to the observation of black holes with masses that are roughly 30 times the mass of the sun. Since then, researchers worldwide have been investigating these black holes, specifically examining whether they could be of primordial origin, meaning that they were produced in the early universe before stars and galaxies were formed.

Hooman Davoudiasl, a at the Brookhaven National Laboratory in New York, has recently introduced a new theory suggesting that the black holes observed by the LIGO/Virgo collaboration originate from a first order quark confinement phase transition. In his paper, published in Physical Review Letters, Davoudiasl implemented this idea using a light scalar that could turn out to be a good dark matter candidate.

Recent detections by the LIGO/Virgo collaboration suggest that there are several black holes that have similar masses (approximately 30 solar masses). This suggests that there might be a population of black holes that are characterized by a typical mass value.

Sep 23, 2019

Physicists invent a new way to search for dark matter using lasers

Posted by in categories: cosmology, physics

Japanese physicists devise technology to discover axion dark matter.

Sep 22, 2019

The 2nd-fastest pulsar, now with gamma rays

Posted by in categories: cosmology, physics

Supernova explosions can crush ordinary stars into neutron stars, composed of exotic, extremely dense matter. Neutron stars are on the order of about 12 miles (20 km) across in contrast to hundreds of thousands of miles across for stars like our sun. Yet they contain mass on the order of 1.4 times that of our sun. Neutron stars have strong magnetic fields. They emit powerful blasts of radiation along their magnetic field lines. If, as a neutron star spins, its beams of radiation periodically point towards Earth, we see the star as a pulsing radio or gamma-ray source. Then the neutron star is also called a pulsar, often compared to a cosmic lighthouse. Modern astronomers know of pulsars spinning with mind-boggling rapidity. The second-fastest one – called PSR J0952-0607 – spins some 707 times a second! Scientists at the Max Planck Institute for Gravitational Physics in Hanover, Germany announced on September 19, 2019, that this pulsar, J0952-0607 – formerly seen only at the radio end of the spectrum – now has been found to pulse also in gamma rays.

J0952-0607 – the number relates to the object’s position in the sky – was first discovered in 2017. It was originally seen to pulse in radio waves, but not gamma rays. The international team that studied it in detail – and recently published new work about it in the peer-reviewed Astrophysical Journal – said in a statement:

The pulsar rotates 707 times in a single second and is therefore the fastest spinning in our galaxy outside the dense stellar environments of globular clusters.

Sep 21, 2019

Is the Multiverse real?

Posted by in category: cosmology

Do we live in the multiverse?

Sep 19, 2019

What came before the Big Bang? A trip through cosmology, multiverses, fifth dimensions and a big bounce

Posted by in categories: cosmology, particle physics

Where were you before you were conceived?

The question itself has no meaning: there was no “you” to be anywhere at all.

Asking questions like “what happened before the Big Bang?” is similarly meaningless.

Continue reading “What came before the Big Bang? A trip through cosmology, multiverses, fifth dimensions and a big bounce” »

Sep 19, 2019

A Huge Experiment Has ‘Weighed’ the Tiny Neutrino, a Particle That Passes Right Through Matter

Posted by in categories: cosmology, evolution, particle physics

An experiment nearly two decades in the making has finally unveiled its measurements of the mass of the universe’s most abundant matter particle: the neutrino.

The neutrino could be the weirdest subatomic particle; though abundant, it requires some of the most sensitive detectors to observe. Scientists have been working for decades to figure out whether neutrinos have mass and if so, what that mass is. The Karlsruhe Tritium Neutrino (KATRIN) experiment in Germany has now revealed its first result constraining the maximum limit of that mass. The work has implications for our understanding of the entire cosmos, since these particles formed shortly after the Big Bang and helped shape the way structure formed in the early universe.

“You don’t get a lot of chances to measure a cosmological parameter that shaped the evolution of the universe in the laboratory,” Diana Parno, an assistant research professor at Carnegie Mellon University who works on the experiment, told Gizmodo.

Sep 19, 2019

Astronomers Found Goliath Pulsar That Can Collapse Forming A Black Hole

Posted by in category: cosmology

Researcher say this massive high speed Neutron star is at the edge to become a black hole.

Sep 17, 2019

Researchers discover massive neutron star that tests the limits of physics

Posted by in categories: cosmology, physics

Astronomers have detected the most massive neutron star ever, and it almost shouldn’t even exist.

Neutron stars are the smallest in the universe, with a diameter comparable to the size of a city like Chicago or Atlanta. They are the leftover remnants of supernovae. But they are incredibly dense, with masses bigger than that of our sun. So think of the sun, compressed into a major city.

In the case of the newly detected neutron star, dubbed J0740+6620, it’s 333,000 times the mass of the Earth and 2.17 times the mass of the sun. But the star is only about 15 miles across. It’s 4,600 light-years from Earth.

Sep 17, 2019

Like wine in a glass

Posted by in category: cosmology

Like wine in a glass, huge clouds of hot gas are sloshing back and forth in a cluster of galaxies about 480 million light years from Earth! Sloshing motions, like those seen here in Abell 2052, redistribute elements forged in supernova explosions such as iron and oxygen!

Want to learn more? https://s.si.edu/2mkQuwt