A Galactic microblazar as a potential accelerator of ultra-high-energy particles

Martí, Josep; Luque-Escamilla, Pedro L.; Marcote, Benito; Abaroa, Leandro; Aguasca-Cabot, Arnau; Combi, Jorge A.; Romero, Gustavo E.; Paredes, Josep M.; García, Federico; Fogantini, Federico; Saavedra, Enzo A.; del Ser, Daniel; van den Eijnden, Jakob
Referencia bibliográfica

Astronomy and Astrophysics

Fecha de publicación:
10
2026
Número de autores
13
Número de autores del IAC
1
Número de citas
0
Número de citas referidas
0
Descripción
Context. Persistent jets from X-ray binaries that are aligned very close to the line of sight could be considered Galactic equivalents of blazars, or `microblazars'. They are also expected to power gamma-ray sources. Aims. We intend to assess a serious candidate apparently fulfilling many of the requirements to be considered a genuine member of this class: IRAS 18293-0941. Methods. We carried out an intense, multi-wavelength observational and theoretical study on our proposed candidate source. Results. With photometric and spectroscopic properties typical of a binary star, this system exhibits clear collimated and one-sided radio emission matching the effects of relativistic motion along a reduced ejection angle. Only fast variability is not observed; it is possibly smoothed by a dense circumstellar envelope. A physical scenario is consistently modelled that also gives credibility to its likely connection with LHAASO J1831-1007u*, an ultra-high-energy source in its immediate vicinity. Conclusions. Our reported identification not only helps fill a gap in Galactic taxonomy, it also potentially strengthens the role of the microblazar and microquasar families in our understanding of the most energetic Milky Way phenomena.