Extended TeV Halos May Commonly Exist around Middle-Aged Pulsars
Abstract
Extended gamma-ray emission around isolated pulsars at TeV energies, also known as TeV halos, have been found around a handful of middle-aged pulsars. The halos are significantly more extended than their pulsar wind nebulae but much smaller than the particle diffusion length in the interstellar medium. The origin of TeV halos is unknown. Interpretations invoke either local effects related to the environment of a pulsar or generic particle transport behaviors. The latter scenario predicts that TeV halos would be a universal phenomena for all pulsars. We searched for extended gamma-ray emission around 36 isolated middle-aged pulsars identified by radio and gamma-ray facilities using 2321 days of data from the High-Altitude Water Cherenkov (HAWC) Observatory. Through a stacking analysis comparing TeV flux models against a background-only hypothesis, we identified TeV halo-like emission at a significance level of . Our results imply that extended TeV gamma-ray halos may commonly exist around middle-aged pulsars. This reveals a previously unknown feature about pulsars and opens a new window to identify the pulsar population that is invisible to radio, x-ray, and GeV gamma-ray observations due to magnetospheric configurations.
Cite
@article{arxiv.2505.00175,
title = {Extended TeV Halos May Commonly Exist around Middle-Aged Pulsars},
author = {A. Albert and 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 A. Bernal 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 P. Desiati and N. Di Lalla and R. Diaz Hernandez and B. L. Dingus and M. A. DuVernois and J. C. Díaz-Vélez and K. Engel and C. Espinoza and K. L. Fan and N. Fraija and J. A. García-González and F. Garfias and H. Goksu and M. M. González and J. A. Goodman and S. Groetsch and J. P. Harding and S. Hernández-Cadena and I. Herzog and D. Huang and F. Hueyotl-Zahuantitla and A. Iriarte and S. Kaufmann and D. Kieda 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. MartínezCastro and J. A. Matthews and P. Miranda-Romagnoli and J. A. Morales-Soto and E. Moreno and M. Mostafá and M. Najafi and A. Nayerhoda and L. Nellen and M. U. Nisa and N. Omodei 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 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 E. Willox and H. Zhou and C. de León},
journal= {arXiv preprint arXiv:2505.00175},
year = {2025}
}
Comments
12 pages, 6 figures, published as Editor's suggestion in Phys. Rev. Lett., April 30, 2025