Category Astronomy/Space

Mauro Sereno et al. Gravitational lensing detection of an extremely dense environment around a galaxy cluster, Nature Astronomy (2018). DOI: 10.1038/s41550-018-0508-y

A study published recently in the journal Nature Astronomy and which questions current models of structure formation in the universe is based on data obtained with the Gran Telescopio Canarias and among its authors is a team of researchers from the Instituto de Astrofísica de Canarias (IAC). The structure of the universe can be compared to that of a sponge, often referred to as the cosmic web. Matter is concentrated along filaments which cross over each other, forming zones where most matter accumulates, and others where there is very little. At the densest points, galaxies group together, forming clusters...

This artist’s conception shows a blazar – the core of an active galaxy powered by a supermassive black hole. Scientists using the VERITAS array have detected gamma rays from the blazar TXS 0506+056, which is also thought to be a source of neutrinos. Credit: M. Weiss/CfA

The VERITAS array has confirmed the detection of gamma rays from the vicinity of a supermassive black hole. While these detections are relatively common for VERITAS, this black hole is potentially the first known astrophysical source of high-energy cosmic neutrinos, a type of ghostly subatomic particle.

On September 22, 2017 the IceCube Neutrino Observatory, a cubic-kilometer neutrino telescope located at the South Pole, detected a high-energy neutrino of potential astrophysical origin...

Using two of the world’s most powerful space telescopes — NASA’s Hubble and ESA’s Gaia — astronomers have made the most precise measurements to date of the universe’s expansion rate. This is calculated by gauging the distances between nearby galaxies using special types of stars called Cepheid variables as cosmic yardsticks. By comparing their intrinsic brightness as measured by Hubble, with their apparent brightness as seen from Earth, scientists can calculate their distances. Gaia further refines this yardstick by geometrically measuring the distances to Cepheid variables within our Milky Way galaxy. This allowed astronomers to more precisely calibrate the distances to Cepheids that are seen in outside galaxies. Credit: NASA, ESA, and A. Feild (STScI)

Using the power and synergy of two s...

Artist’s impression of the active galactic nucleus. The supermassive black hole at the center of the accretion disk sends a narrow high-energy jet of matter into space, perpendicular to the disc. Credit: DESY, Science Communication Lab

Scientists trace a single neutrino back to a galaxy billions of light years away. Using an internationally organised astronomical dragnet, scientist have for the first time located a source of high-energy cosmic neutrinos, that travel billions of light years through the universe, flying unaffected through stars, planets and entire galaxies. The joint observation campaign was triggered by a single neutrino that had been recorded by the IceCube neutrino telescope at the South Pole, on 22 September 2017...