1. Study of Long-term Spectral Evolution and X-Ray and γ-Ray Correlation of Blazars Seen by HAWC
- Author
-
R. Alfaro, C. Alvarez, A. Andrés, J.C. Arteaga-Velázquez, D. Avila Rojas, H.A. Ayala Solares, R. Babu, E. Belmont-Moreno, A. Bernal, K.S. Caballero-Mora, T. Capistrán, A. Carramiñana, F. Carreón, S. Casanova, U. Cotti, J. Cotzomi, S. Coutiño de León, E. De la Fuente, D. Depaoli, N. Di Lalla, R. Diaz Hernandez, B.L. Dingus, M.A. DuVernois, M. Durocher, J.C. Díaz-Vélez, K. Engel, C. Espinoza, K.L. Fan, N. Fraija, S. Fraija, J.A. García-González, F. Garfias, A. Gonzalez Muñoz, M.M. González, J.A. Goodman, S. Groetsch, J.P. Harding, S. Hernández-Cadena, I. Herzog, D. Huang, F. Hueyotl-Zahuantitla, A. Iriarte, V. Joshi, S. Kaufmann, D. Kieda, A. Lara, W.H. Lee, J. Lee, H. León Vargas, J.T. Linnemann, A.L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, I. Martinez-Castellanos, J. Martínez-Castro, J.A. Matthews, P. Miranda-Romagnoli, J.A. Montes, E. Moreno, M. Mostafá, A. Nayerhoda, L. Nellen, M.U. Nisa, R. Noriega-Papaqui, N. Omodei, M. Osorio, Y. Pérez Araujo, E.G. Pérez-Pérez, C.D. Rho, D. Rosa-González, E. Ruiz-Velasco, H. Salazar, D. Salazar-Gallegos, A. Sandoval, M. Schneider, J. Serna-Franco, A.J. Smith, Y. Son, R.W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Ureña-Mena, E. Varela, L. Villaseñor, X. Wang, I.J. Watson, K. Whitaker, E. Willox, S. Yun-Cárcamo, H. Zhou, C. de León, HAWC collaboration, Abraham D. Falcone, and Fredric Hancock
- Subjects
Active galactic nuclei ,High energy astrophysics ,Blazars ,Gamma-ray astronomy ,Gamma-ray detectors ,Gamma-ray observatories ,Astrophysics ,QB460-466 - Abstract
The HAWC Observatory collected 6 yr of extensive data, providing an ideal platform for long-term monitoring of blazars in the very high energy (VHE) band, without bias toward specific flux states. HAWC continuously monitors blazar activity at TeV energies, focusing on sources with a redshift of z ≤ 0.3, based on the Third Fermi-LAT Catalog of High-Energy sources. We specifically focused our analysis on Mrk 421 and Mrk 501, as they are the brightest blazars observed by the HAWC Observatory. With a data set of 2143 days, this work significantly extends the monitoring previously published, which was based on 511 days of observation. By utilizing HAWC data for the VHE γ -ray emission in the 300 GeV–100 TeV energy range, in conjunction with Swift-XRT data for the 0.3–10 keV X-ray emission, we aim to explore potential correlations between these two bands. For Mrk 501, we found evidence of a long-term correlation. Additionally, we identified a period in the light curve where the flux was very low for more than 2 yr. On the other hand, our analysis of Mrk 421 measured a strong linear correlation for quasi-simultaneous observations collected by HAWC and Swift-XRT. This result is consistent with a linear dependence and a multiple-zone synchrotron self-Compton model to explain the X-ray and γ -ray emission. Finally, as suggested by previous findings, we confirm a harder-when-brighter behavior in the spectral evolution of the flux properties for Mrk 421. These findings contribute to the understanding of blazar emissions and their underlying mechanisms.
- Published
- 2025
- Full Text
- View/download PDF