Category Astronomy/Space

Age structure of the Milky Way’s halo

Using colors to identify the approximate ages of >130,000 stars in the Milky Way’s halo, Notre Dame astronomers have produced the clearest picture yet of how the galaxy formed more than 13.5 billion years ago. The chronographic (age) map supports a hierarchical model of galaxy formation. That model, developed by theoreticians over the past few decades, suggests that the Milky Way formed by merging and accretion of small mini-halos containing stars and gas, and that the oldest of the Milky Way’s stars are at the center of the galaxy and younger stars and galaxies merged with the Milky Way, drawn in by gravity over billions of years...

The unusual cluster Terzan. Credit: NASA/ESA/Hubble/F. Ferraro

A fossilised remnant of the early Milky Way harbouring stars of hugely different ages has been revealed. This stellar system resembles a globular cluster, but is like no other cluster known. It contains stars remarkably similar to the most ancient stars in the Milky Way and bridges the gap in understanding between our galaxy’s past and its present.

Terzan 5, 19 000 light-years from Earth, has been classified as a globular cluster for the 40-odd years since its detection. Now, an Italian-led team of astronomers have discovered that Terzan 5 is like no other globular cluster known...

Artist’s impression of dark matter clumps around a Milky Way-like galaxy. These clumps are invisible and can only be detected through their gravitational effect on visible matter. The clumps, also known as subhaloes, come in a range of sizes with the smallest one set by the mass of the yet to be discovered dark matter particle. The more massive the dark matter particle, the slower the dark matter moves, and the easier it is for regions in the early universe to collapse and form small subhaloes. In this work, a tidal stream from a disrupting globular cluster is used to probe their presence. Credit: V. Belokurov, D. Erkal, S.E. Koposov (IoA, Cambridge). Photo: Color image of M31 from Adam Evans. Dark matter clumps from Aquarius, Volker Springel (HITS)

The discovery of two massive holes punch...

The interior structure of Uranus is illustrated. Credit: MIPT Press office

The depths of Uranus, Neptune and their satellites may contain extraordinary compounds, such as Carbonic and Orthocarbonic acids (aka Hitler’s acid). These gas giants consist mainly of hydrogen, carbon and oxygen, which are the 3 cornerstones of organic chemistry. Using computer modeling, chemists from MIPT and Skoltech found at high pressures, typical for the interiors of such planets, exotic molecular and polymeric compounds are formed. “We have found that at a pressure of several million atmospheres unexpected compounds should form in their interiors. The cores of these planets may largely consist of these exotic materials,” says Prof. Artem Oganov.

A team led by Professor Oganov developed the world’s most univer...