New Galactic Microblazar Discovered: Black Hole Jets Point Toward Earth
- Astronomers have discovered a new galactic microblazar named IRAS 18293−0941 located approximately 12,000 light-years from Earth.
- The system pairs a massive star with a black hole in a tight 11.4-day orbital period.
- Researchers analyzed the microblazar using data from the MeerKAT radio observatory in South Africa and the European VLBI Network (EVN).
Astronomers have discovered a new galactic microblazar named IRAS 18293−0941 located approximately 12,000 light-years from Earth. Announced in a study published on the preprint server arXiv and accepted in the journal Astronomy and Astrophysics, the international research team led by Josep Martí found that the binary system produces twin particle jets streaming outward at nearly three-quarters the speed of light.
Inside the Binary System IRAS 18293−0941
The system pairs a massive star with a black hole in a tight 11.4-day orbital period. Due to this proximity, stellar material streams toward the black hole to form an accretion disk. Before crossing the event horizon, a fraction of this infalling matter is accelerated outward into focused particle jets moving at roughly 0.75 times the speed of light. Earth happens to sit directly in the path of one of these relativistic jets. This orientation triggers the relativistic Doppler effect, or beaming, which brightly illuminates the emission and shifts it toward the blue end of the spectrum via Doppler blue-shifting. Because these stellar-mass systems mirror the geometry of giant blazars found in galactic cores, researchers classify them as microblazars.
Radio Observations Reveal a 100-Light-Year Bubble
Researchers analyzed the microblazar using data from the MeerKAT radio observatory in South Africa and the European VLBI Network (EVN). The EVN combines antennas separated by thousands of kilometers across South Africa, Great Britain, the Netherlands, and Spain to map radio sources with high precision. MeerKAT observations uncovered an expansive radio bubble measuring roughly 100 light-years in diameter. While the jet pointing toward Earth appears as a compact, bright spot on radio images, the unseen counter-jet travels in the opposite direction. Where this counter-jet collides with surrounding interstellar gas, it generates a shock wave that heats the material and creates a luminous hot spot.
Connection to Ultra-High-Energy Gamma Rays
The research team connects the counter-jet’s impact point to LHAASO J1831–1007u∗, a previously known gamma-ray source originally cataloged by China’s LHAASO observatory. Photons from this high-energy source reach extreme energy levels of up to 100 teraelectronvolts. The findings suggest that galactic microblazars like IRAS 18293−0941 can act as potential accelerators for ultra-high-energy particles within the Milky Way.