Ultra-High-Energy Gamma-Ray Bubble around Microquasar V4641 Sgr
Abstract
Microquasars are laboratories for the study of jets of relativistic particles produced by accretion onto a spinning black hole. Microquasars are near enough to allow detailed imaging of spatial features across the multiwavelength spectrum. The recent extension of the spatial morphology of a microquasar, SS 433, to TeV gamma rays \cite{abeysekara2018very} localizes the acceleration of electrons at shocks in the jet far from the black hole \cite{hess2024ss433}. Here we report TeV gamma-ray emission from another microquasar, V4641~Sgr, which reveals particle acceleration at similar distances from the black hole as SS~433. Additionally, the gamma-ray spectrum of V4641 is among the hardest TeV spectra observed from any known gamma-ray source and is detected up to 200 TeV. Gamma rays are produced by particles, either electrons or hadrons, of higher energies. Because electrons lose energy more quickly the higher their energy, such a spectrum either very strongly constrains the electron production mechanism or points to the acceleration of high-energy hadrons. This observation suggests that large-scale jets from microquasars could be more common than previously expected and that microquasars could be a significant source of Galactic cosmic rays. high energy gamma-rays also provide unique constraints on the acceleration mechanisms of extra-Galactic cosmic rays postulated to be produced by the supermassive black holes and relativistic jets of quasars. The distance to quasars limits imaging studies due to insufficient angular resolution of gamma-rays and due to attenuation of the highest energy gamma-rays by the extragalactic background light.
Cite
@article{arxiv.2410.16117,
title = {Ultra-High-Energy Gamma-Ray Bubble around Microquasar V4641 Sgr},
author = {R. Alfaro and C. Alvarez and J. C. Arteaga-Velázquez and D. Avila Rojas and H. A. Ayala Solares and R. Babu and E. Belmont-Moreno and K. S. Caballero-Mora and T. Capistrán and A. Carramiñana and S. Casanova and U. Cotti and J. Cotzomi and S. Coutiño de León and E. De la Fuente and D. Depaoli and N. Di Lalla and R. Diaz Hernandez and B. L. Dingus and M. A. DuVernois and M. Durocher and J. C. Díaz-Vélez and K. Engel and C. Espinoza and K. L. Fan and K. Fang and N. Fraija and S. Fraija and J. A. García-González and F. Garfias and A. Gonzalez Muñoz and M. M. González and J. A. Goodman and S. Groetsch and J. P. Harding and I. Herzog and J. Hinton and D. Huang and F. Hueyotl-Zahuantitla and P. Hüntemeyer and A. Iriarte and V. Joshi and S. Kaufmann and D. Kieda and C. de León and J. Lee and H. León Vargas and J. T. Linnemann and A. L. Longinotti and G. Luis-Raya and K. Malone and O. Martinez and J. Martínez-Castro and J. A. Matthews and P. Miranda-Romagnoli and J. A. Morales-Soto and E. Moreno and M. Mostafá and A. Nayerhoda and L. Nellen and M. Newbold and M. U. Nisa and R. Noriega-Papaqui and L. Olivera-Nieto and N. Omodei and M. Osorio and Y. Pérez Araujo and E. G. Pérez-Pérez and C. D. Rho and D. Rosa-González and E. Ruiz-Velasco and H. Salazar and D. Salazar-Gallegos and A. Sandoval and M. Schneider and J. Serna-Franco and A. J. Smith and Y. Son and R. W. Springer and O. Tibolla and K. Tollefson and I. Torres and R. Torres-Escobedo and R. Turner and F. Ureña-Mena and E. Varela and L. Villaseñor and X. Wang and I. J. Watson and E. Willox and S. Yun-Cárcamo and H. Zhou},
journal= {arXiv preprint arXiv:2410.16117},
year = {2024}
}