Unveiling the Milky Way's Galactic Plane: New Images Reveal Stunning Detail

Strategic Insights -

The Milky Way galaxy is a complex and dynamic environment, observable in various ways, including visible light, radio waves, and charged particles. For decades, astronomers have used radio telescopes to explore our galaxy. A recent study published in Publications of the Astronomical Society of Australia has provided new insights into the structure of our galaxy's galactic plane by observing the entire sky with the Murchison Widefield Array.

Key Takeaways:

  • The Murchison Widefield Array, a radio telescope in the Australian outback, was used to observe the entire southern hemisphere sky for the GaLactic and Extragalactic All-sky MWA (or GLEAM) survey, covering a broad range of radio wave frequencies.
  • The wide frequency coverage of GLEAM gave astronomers the first "radio colour" map of the sky, including the galaxy itself, revealing the diffuse glow of the galactic disk and thousands of distant galaxies.
  • The GLEAM-eXtended survey (GLEAM-X) observed the sky with higher resolution and sensitivity, resulting in a higher-resolution mosaic of the galaxy.
  • A new imaging technique called image domain gridding was used to combine thousands of GLEAM and GLEAM-X observations, forming a huge mosaic of the galaxy.
  • The mosaic covers 95% of the Milky Way visible from the southern hemisphere, spanning radio frequencies from 72 to 231 MHz.
  • The broad frequency range allows astronomers to see different sources with their "radio colour," depending on whether the radio waves are produced by cosmic magnetic fields or by hot gas.
  • The new radio portrait of the Milky Way is the most sensitive, widest-area map at these low frequencies to date.
  • The power of this image will be surpassed when the new SKA-Low telescope is complete and operational, which is still a few years away.

Statistics:

  • The Murchison Widefield Array has 4,096 antennas spread over several square kilometers.
  • The GLEAM survey was conducted between 2013 and 2015.
  • The GLEAM-eXtended survey was conducted in 2018.
  • The mosaic covers 95% of the Milky Way visible from the southern hemisphere.
  • The radio frequencies covered by the mosaic range from 72 to 231 MHz.
  • The mosaic covers the entire southern hemisphere sky.

Sources:

  • Publications of the Astronomical Society of Australia
  • Natasha Hurley-Walker receives funding from the Australian Research Council
  • Silvia Mantovanini does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment
  • New images reveal the Milky Way's stunning galactic plane in more detail than ever before -- https://theconversation.com/new-images-reveal-the-milky-ways-stunning-galactic-plane-in-more-detail-than-ever-before-264688