anglo-australian telescope Archives

October 4, 2024October 4, 2024 by Matt Williams

The GALAH Fourth Data Release Provides Vital Data on One Million Stars in the Milky Way.

Day and night at the Anglo Australian Telescope. Half right image taken in the late afternoon, the Moon is up. Half left image taken just some few minutes before the beginning of the morning twilight of the same night. Credit: Dr Ángel R. López-Sánchez/Australian Astronomical Optics/Macquarie University/ASTRO 3D

For the past ten years, Australia’s ARC Centre of Excellence in All Sky Astrophysics in 3 Dimensions (ASTRO 3D) has been investigating star formation, chemical enrichment, migration, and mergers in the Milky Way with the Anglo-Australian Telescope (AAT). Their work is part of the GALactic Archaeology with HERMES (GALAH) project, an international collaboration of more than 100 scientists from institutes and universities worldwide. These observations have led to the highest spectral resolution multi-dimensional datasets for over a million stars in the Milky Way.

Previous GALAH data releases have led to many significant discoveries about the evolution of the Milky Way, the existence of exoplanets, hidden star clusters, and many more. In the fourth data release (DR4), the GALAH team released the chemical fingerprints (spectra) for almost 1 million stars. This data is the pinnacle of the 10-year project and was released during the 50th anniversary celebration of the AAT. According to the study that accompanied the release, the data will inform decades of research into the formation and evolution of our galaxy.

August 8, 2020August 8, 2020 by Matt Williams

A Globular Cluster was Completely Dismantled and Turned Into a Ring Around the Milky Way

Artist’s impression of the thin stream of stars torn from the Phoenix globular cluster, wrapping around our Milky Way (left). For the study, the astronomers targeted bright Red Giant stars, to measure the chemical composition of the disrupted Phoenix globular cluster (artist’s impression on right). Credit: James Josephides (Swinburne Astronomy Productions) and the S5 Collaboration.

According to predominant theories of galaxy formation, the earliest galaxies in the Universe were born from the merger of globular clusters, which were in turn created by the first stars coming together. Today, these spherical clusters of stars are found orbiting around the a galactic core of every observable galaxy and are a boon for astronomers seeking to study galaxy formation and some of the oldest stars in the Universe.

Interestingly enough, it appears that some of these globular clusters may not have survived the merger process. According to a new study by an international team of astronomers, a cluster was torn apart by our very own galaxy about two billion years ago. This is evidenced by the presence of a metal-poor debris ring that they observed wrapped around the entire Milky Way, a remnant from this ancient collision.

March 11, 2014December 23, 2015 by Elizabeth Howell

This Video Is The Closest You’ll Get To Experiencing Warp Drive

A simulation of the "cosmic web" believed to connect galaxies. A galaxy can move into and out of this web throughout its lifetime. A void is visible in the center of the image, a spot where researchers found galaxy "tendrils." Credit: Cunnama, Power, Newton and Cui (ICRAR).

Engage! This video shows some results of the the Galaxy and Mass Assembly catalogue, including the real positions of galaxies. The simulated flythrough, with galactic bodies whizzing by, appears like the view from the Starship Enterprise going at high speed.

Unlike that science fiction series, however, the data you’re seeing has charted information in it (although the galaxies have been biggified for our “viewing pleasure.”)

It’s all part of new research showing that galaxies in “vast empty regions” of the Universe are “aligned into delicate strings,” stated the International Centre for Radio Astronomy Research.

“The spaces in the cosmic web are thought to be staggeringly empty,” stated Mehmet Alpaslan, a Ph.D. candidate at St Andrews University, Scotland who led the research. “They might contain just one or two galaxies, as opposed to the hundreds that are found in big clusters.”

His team discovered faint galaxies lined up in areas of space believed to hold practically nothing. The work is part of an emerging set of research looking at voids in the “cosmic web”, or the filaments that are believed to hold galaxies together across great distances.

Alpaslan’s team used a galaxy census — the biggest ever — of the skies in the south created with observations of Australia’s Anglo-Australian Telescope. The arrangement of galaxies in these voids was surprising to researchers.

“We found small strings composed of just a few galaxies penetrating into the voids, a completely new type of structure that we’ve called ‘tendrils’,” stated Alpaslan.

It will be interesting to see what further research reveals. As the press release accompanying this news states, “These aren’t the voids you’re looking for.”

Alpaslan’s study will be published in the Monthly Notices of the Royal Astronomical Society. You can read the research in preprint version on Arxiv.

Source: International Centre for Radio Astronomy Research