Conveners
X-Ray and Gamma-Ray Binaries
- Christo Venter
A discrete jet component (blob) ejection and its subsequent deceleration were observed in the 2019/2020 outburst of the low-mass X-ray binary MAXI J1348–630. A first kinematic analysis of the deceleration due to an abrupt transition from an evacuated cavity to the interstellar medium suggested a kinetic energy exceeding $10^{46}$ erg, surpassing estimates of the available total ejection...
Gamma-ray binaries produce multi-wavelength, non-thermal emission that peaks at energies >1 MeV. It is largely understood that the high energy emission in these systems are produced in a termination shock formed between the stellar wind and/or circumstellar disc of the O/Be companion and the relativistic pulsar wind from a young, rapidly rotating, neutron star compact object. The gamma-ray...
Gamma-ray binaries are a rare class of high-mass binary systems that produce non-thermal emission peaking in the gamma-ray regime (in a $\nu F_\nu$ distribution). The system PSR B1259–63/LS 2883 consists of a young pulsar in a 3.4-year orbit around an O9.5 Ve star. It was the first binary system discovered to host a pulsar orbiting a non-degenerate companion. The pulsed radio emission is...
Context. Gamma-ray binaries are a rare subclass of high-mass binary systems composed of a compact object (either a neutron star or a black hole) and an O- or B-type stellar companion. These systems exhibit broadband non-thermal emission that peaks in the gamma-ray regime and serve as ideal laboratories for studying relativistic particle acceleration, wind–wind interactions, and extreme...
Magnetically controlled accreting white dwarf binaries, which includes polars and intermediate polars, provide unique laboratories for high-energy particle acceleration in compact stellar systems. Their strong magnetic fields, rapid accretion flows, and dynamic magnetospheres enable distinct acceleration channels. In polars, which rotate synchronously with strong magnetic locking, unipolar...
The Large High Altitude Air Shower Observatory (LHAASO) has recently reported five Galactic microquasars as Ultra-High-Energy (UHE) gamma-ray emitters (>100 TeV), an unexpected result that challenges conventional models of Galactic particle acceleration. Among these sources, the microquasar V4641 Sgr exhibits gamma-ray emission up to ~0.8 PeV, as well as the hardest UHE spectrum. The...
