Radio Galaxies 

News: Researchers have successfully recreated the complex structure of the newly discovered Twin Radio Galaxies (TRGs), revealing insights that are transforming our understanding of the physics behind the jets emitted by these systems.

About Radio Galaxies

• Radio galaxies are galaxies that emit exceptionally strong radio waves, far brighter than typical galaxies.
• Their radio emission comes from giant lobes of plasma that extend far beyond the galaxy’s visible stars.
• Structure of Radio Galaxies: At the core of a radio galaxy lies an AGN powered by a supermassive black hole.
  • Gas falling into the black hole heats up and forms an accretion disk.
  • Some of this material is funneled into relativistic jets, which inflate the radio lobes.
• Key Features:
  • Radio lobes can span millions of light-years, making them among the largest structures in the universe.
  • They usually appear in pairs, positioned on opposite sides of the galaxy.
  • The radiation is produced by synchrotron emission, electrons moving near light speed in magnetic fields.
• Types of Radio Galaxies:
  • Broad-line radio galaxies: Broad-line radio galaxies show broad emission lines of elements such as hydrogen, oxygen, and silicon in their optical spectra.
    • These broad lines are produced by fast-moving gas located close to the active galactic nucleus (AGN).
  • Narrow-line radio galaxies: Narrow-line radio galaxies show only narrow emission lines, which indicate slower-moving or cooler gas in their environment.
    • The narrow lines suggest that the emitting gas is located farther away from the black hole compared to the gas in broad-line radio galaxies.
• Why They Matter
  • It reveals how supermassive black holes interact with their host galaxies.
  • It act as beacons detectable across vast cosmic distances.
  • It help astronomers study: Galaxy evolution, Intergalactic magnetic fields and High-energy particle physics.