Ultra-high-energy gamma-ray bubble around microquasar V4641 Sgr

The High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory has provided new insights into the microquasar V4641 Sagittarii (V4641 Sgr), a binary system composed of a massive star and a black hole. The observations made by the HAWC Collaboration, published in Nature, mark the first detection of very high energy (VHE) gamma rays from this source, revealing previously unknown particle acceleration processes in the system. V4641 Sgr is known for its dramatic outbursts, during which relativistic jets are launched, making it a key object of study for understanding jet formation and black hole accretion mechanisms. The VHE gamma-ray emission detected by HAWC provides critical information about the extreme conditions near the black hole, supporting models of jet-powered particle acceleration and shedding light on the complex interactions between the jets and surrounding material. These findings have broad implications for the study of microquasars and their role as sources of cosmic rays, offering a new perspective on high-energy phenomena in such systems.