Japanese physicists devise technology to discover axion dark matter.
Category: cosmology – Page 363
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.
Is the Multiverse real?
Posted in cosmology
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.
Confused? You see, the birth of the Universe is not just the birth of subatomic particles and energy, it is also the beginning of time and space.
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.
Researcher say this massive high speed Neutron star is at the edge to become a black hole.
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.
Like wine in a glass
Posted in 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
Field notes from space-time | We’re only just grasping how cosmic black holes and Einstein’s theories relate – and that deepens our sense of wonder, says Chanda Prescod-Weinstein.
A new study of gravitational waves from merging black holes agrees with the predictions of the general theory of relativity.