dark matter tagged posts

This artist’s impression shows the spiral galaxy NGC 4921 based on observations made by the Hubble Space Telescope. Credit: ICRAR, NASA, ESA, the Hubble Heritage Team. STScI/AURA

It’s the big astrophysical whodunnit. Across the Universe, galaxies are being killed and the question scientists want answered is, what’s killing them? New research published today by a global team of researchers, based at the International Centre for Radio Astronomy Research (ICRAR), seeks to answer that question. The study reveals that ram-pressure stripping is more prevalent than previously thought, driving gas from galaxies and sending them to an early death by depriving them of the material to make new stars.

The study of 11,000 galaxies shows their gas – the lifeblood for star formation – is being violently ...

An overview of the NA64 experimental set-up at CERN. NA64 hunts down dark photons, hypothetic dark matter particles. Credit: Maximilien Brice/CERN

One of the biggest puzzles in physics is that 85% of the matter in our universe is “dark”: it does not interact with the photons of the conventional electromagnetic force and is therefore invisible to our eyes and telescopes. Although the composition and origin of dark matter are a mystery, we know it exists because astronomers observe its gravitational pull on ordinary visible matter such as stars and galaxies.

Some theories suggest that, in addition to gravity, dark matter particles could interact with visible matter through a new force, which has so far escaped detection...

This image shows the galaxy cluster Abell 1689, with the mass distribution of the dark matter in the gravitational lens overlaid (in purple). The mass in this lens is made up partly of normal (baryonic) matter and partly of dark matter. Credit: NASA, ESA, E. Jullo (JPL/LAM), P. Natarajan (Yale) and J-P. Kneib (LAM).

Currently, one of the strongest candidates for dark matter is weakly interacting massive particles, or WIMPS, although so far this hypothetical particle has not yet been directly detected. Now in a new study, physicists have proposed that dark matter is not a WIMP, and further, it is not any particle that is so far known or theorized to exist...

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...