dark matter tagged posts

Top: Gamma rays (magenta lines) coming from a bright source like NGC 1275 in the Perseus galaxy cluster should form a particular type of spectrum (right). Bottom: Gamma rays convert into hypothetical axion-like particles (green dashes) and back again when they encounter magnetic fields (gray curves). The resulting gamma-ray spectrum ((lower curve at right) would show unusual steps and gaps not seen in Fermi data, which means a range of these particles cannot make up a portion of dark matter. Credits: SLAC National Accelerator Laboratory/Chris Smith

Dark matter, the mysterious substance that constitutes most of the material universe, remains as elusive as ever...

Binary black holes recently discovered by the Ligo-Virgo collaboration could be primordial entities that formed just after the Big Bang. Primordial black hole binaries were discussed extensively in the 1990s. However, interest in them waned when observations implied that their number was limited

New scenario from Japan offers clues about the early universe. Binary black holes recently discovered by the LIGO-Virgo collaboration could be primordial entities that formed just after the Big Bang. If further data support this observation, it could mark the first confirmed finding of a primordial black hole, guiding theories about the beginnings of the universe.

In February, the LIGO-Virgo collaboration announced the first successful detection of gravitational waves...

The Milky Way. Credit: NASA

It is a galactic challenge, to be sure, but Gwendolyn Eadie is getting closer to an accurate answer to a question that has defined her early career in astrophysics: what is the mass of the Milky Way? The short answer, so far, is 7 X 1011 solar masses. In terms that are easier to comprehend, that’s about the mass of our Sun, multiplied by 700 billion. The Sun, for the record, has a mass of 2 nonillion (that’s 2 followed by 30 zeroes) kilograms, or 330,000 times the mass of Earth.

“And our galaxy isn’t even the biggest galaxy,” Eadie says.
Measuring the mass of our home galaxy, or any galaxy, is particularly difficult. A galaxy includes not only stars, planets, moons, gases, dust and other objects and material, but also a big helping of dark matter.

Eadie, a PhD c...

Slices of collapsing gas within dark matter halos on three different spacial scales: from 10,0000 to 10 light years across. The colors represent the gas density, from low density (blue color) to much larger density (red color). The gas on the smallest spatial scales is going to form a supermassive black hole. Credit: Isaac Shlosman, University of Kentucky

Often containing more than a billion times the mass than our Sun, supermassive black holes have perplexed humans for decades. But new research by astrophysicist Isaac Shlosman and collaborators will help to understand the physical processes, providing details of how supermassive black holes formed 13 billion years ago...