Category Astronomy/Space

Hubble Maps Giant Halo around Andromeda Galaxy

This illustration shows the location of the 43 quasars scientists used to probe Andromeda’s gaseous halo. These quasars—the very distant, brilliant cores of active galaxies powered by black holes—are scattered far behind the halo, allowing scientists to probe multiple regions. Looking through the immense halo at the quasars’ light, the team observed how this light is absorbed by the halo and how that absorption changes in different regions. By tracing the absorption of light coming from the background quasars, scientists are able to probe the halo’s material.
Credits: NASA, ESA, and E. Wheatley (STScI)

In a landmark study, scientists using NASA’s Hubble Space Telescope have mapped the immense envelope of gas, called a halo, surrounding the Andromeda galaxy, our nearest large g...

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New observations of Black Hole devouring a Star Reveal Rapid Disk Formation

tde-simulation-450.jpg
This image from a computer simulation shows the rapid formation of an accretion disk during the disruption of a star by a supermassive black hole. (Image credit: Jamie Law-Smith and Enrico Ramirez-Ruiz)

When a star passes too close to a supermassive black hole, tidal forces tear it apart, producing a bright flare of radiation as material from the star falls into the black hole. Astronomers study the light from these “tidal disruption events” (TDEs) for clues to the feeding behavior of the supermassive black holes lurking at the centers of galaxies.

New TDE observations led by astronomers at UC Santa Cruz now provide clear evidence that debris from the star forms a rotating disk, ie an accretion disk, around the black hole...

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Galactic Bar Paradox Resolved in Cosmic Dance

Snapshots from a Milky Way galaxy simulation. The bar in the centre and the spiral arms are thought to rotate at different speeds. If they are disconnected the bar shows its true and smaller structure (left). Every time they meet, the bar appears longer and its rotation slower (right).
Credit T. Hilmi / University of Surrey
Licence type Attribution (CC BY 4.0)

New light has been shed on a mysterious and long-standing conundrum at the very heart of our galaxy. The new work offers a potential solution to the so-called ‘Galactic bar paradox’, whereby different observations produce contradictory estimates of the motion of the central regions of the Milky Way. The results are published in Monthly Notices of the Royal Astronomical Society.

The majority of spiral galaxies, like our home the ...

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Ancient Star explosions revealed in Deep-sea Sediments

A mystery surrounding the space around our solar system is unfolding thanks to evidence of supernovae found in deep-sea sediments.

Professor Anton Wallner, a nuclear physicist at ANU, led the study which shows Earth has been travelling for the last 33,000 years through a cloud of faintly radioactive dust.

“These clouds could be remnants of previous supernova explosions, a powerful and super bright explosion of a star,” Professor Wallner said.

Professor Wallner conducted the research at the ANU Heavy Ion Accelerator Facility (HIAF). He also holds joint positions at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Technical University Dresden (TUD) in Germany.

The researchers searched through several deep-sea sediments from two different locations that date back 33,000 years using the...

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