Published 03:35 IST, December 11th 2020
Giant X-Ray Bubbles discovered trapped in Milky Way's halo above and below galactic plane
A large hourglass-shaped X-Ray structure that scientists dubbed as the 'eROSITA bubbles' was discovered trapped with energies higher than the Fermi bubbles.
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Astronomers have detected giant bubbles of X-radiations in the halo of the Milky Way trapped above and below the Galactic Plane. The bubbles are so humungous in size that the structures practically engulfed the previously discovered game rays Fermi bubbles. In a new survey of the sky, a team of astrophysicists from the Max Planck Institute for Extraterrestrial Physics in Germany discovered the mammoth hot gas structures in the galactic discs from the eROSITA X-ray telescope on-board the Spektrum Roentgen Gamma (SRG) observatory.
The large scale X-ray bubbles were produced due to the shock waves generated by past energetic activity in the center of the Galaxy, researchers said in a report published on December 9. A large hourglass-shaped structure that the scientists dubbed as the "eROSITA bubbles" was discovered trapped with energies higher than the Fermi bubbles below the plane of the Milky Way occupying most of the southern sky.
According to the scientists, a similar kind of structure known as the "North polar spur" was down to have existed in the Northern sky, which was formed due to a supernova explosion. "Spectral and angular resolution, eROSITA has been able to map the entire X-ray sky to unprecedented depth, revealing the southern bubble unambiguously," Michael Freyberg, a senior scientist working on the SRG observatory telescope explained in the report. He added, that the structure comprised a medium energy band (0.6-1.0 keV), was as huge as the entire Milky Way and was measured across several kiloparsecs (or up 50,000 light-years).
"eROSITA bubbles show striking morphological similarities to the well-known ‘Fermi bubbles’ detected at in gamma-rays by the Fermi telescope," scientists informed.
'Cosmic cycle' of matter
Peter Predehl, the first author of the study published in Nature noted that the bubbles had sharp boundaries like Fermi bubbles due to shocks caused by the massive injection of energy, which now clarified the morphology of such structures.
"This discovery will help astronomers to understand the cosmic cycle of matter in and around the Milky Way, and other galaxies," he said. The vast ordinary baryonic matter that resides in the tenuous haloes of the galaxies with temperatures of millions of degrees has been a subject of research for scientists.
With eROSITA bubbles discovery, scientists could establish that these hot gas envelopes were formed due to a burst of star formation or by an outburst from the supermassive black hole with active galactic nuclei (AGN) at the Galactic center.
[Gamma-ray bubbles, or Fermi Bubbles that extend 50,000 light-years. Credit: NASA]
[Schematic view of the eROSITA (yellow) and Fermi bubbles (purple). Credit: Max Planck Institute for Extraterrestrial Physics]
"Scientists have been looking for the gigantic fingerprints of such past violent activity around many galaxies in the past," Andrea Merloni, eROSITA Principal Investigator explained. The eROSITA bubbles now provide strong support for large-scale interactions between the Galaxy core and the halo around it, he added.
03:35 IST, December 11th 2020