A representation of two competing black hole models: lamp-post and extended. The black dot is the black hole, blue is its accretion disk, and red is the corona.
Credit: Fumiya Imazato, Hiroshima University

X-ray polarimetry resolves shape of matter around Cygnus X-1 black hole. In an international collaboration between Japan and Sweden, scientists clarified how gravity affects the shape of matter near the black hole in binary system Cygnus X-1. Their findings, which were published in Nature Astronomy this month, may help scientists further understand the physics of strong gravity and the evolution of black holes and galaxies.

Near the center of the constellation of Cygnus is a star orbiting the first black hole discovered in the universe...

Salmonella bacteria cause about 1.2 million illnesses a year, but a new Stanford study identified a molecule that offers natural protection against the pathogen.
Kateryna Kon/Shutterstock

Researchers at the Stanford University School of Medicine have identified a molecule that serves as natural protection against one of the most common intestinal pathogens. Propionate, a byproduct of metabolism by a group of bacteria called the Bacteroides, inhibits the growth of Salmonella in the intestinal tract of mice, according to the researchers. The finding may help to explain why some people are better able to fight infection by Salmonella and other intestinal pathogens and lead to the development of better treatment strategies.

The researchers determined that propionate doesn’t trigger the immune r...

A phonon laser formed by coupled optical resonators. Mechanical vibrations in resonator (blue) could be enhanced when the frequency difference of two optical supermodes matches with the frequency mechanical vibrations.
Credit: Micro/Nano Photonics Lab

New laser uses light to create sound. A team of international researchers led by engineers at Washington University in St. Louis has seen the light and now has a lasing system that produces “good vibrations.” They developed a lasing system already adept at producing tiny light packets called photons into a tunable system that also makes little bits of mechanical energy called phonons – the energy products of oscillation, or vibration...

Artist impression of the “reverse shock” echoing back though the jets of the gamma-ray burst (GRB 161219B).
Credit: NRAO/AUI/NSF, S. Dagnello

ALMA creates its first-ever movie of cosmic explosion. In the blink of an eye, a massive star more than 2 billion light-years away lost a million-year-long fight against gravity and collapsed, triggering a supernova and forming a black hole at its center. This newborn black hole belched a fleeting yet astonishingly intense flash of gamma rays known as a gamma-ray burst (GRB) toward Earth, where it was detected by NASA’s Neil Gehrels Swift Observatory on 19 December 2016.

While the gamma rays from the burst disappeared from view a scant seven seconds later, longer wavelengths of light from the explosion – including X-ray, visible light, and radio – con...