51. Evidence of 200 TeV photons from HAWC J1825-134
- Author
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R. Noriega-Papaqui, J. R. Angeles Camacho, Gerd J. Kunde, Luis Villaseñor, C. Brisbois, K. Tollefson, J. T. Linnemann, Catalina Espinoza, D. Garcia, F. Serna, Nicola Omodei, A. Iriarte, H. A. Ayala Solares, Lukas Nellen, I. Torres, E. Belmont-Moreno, Gwenael Giacinti, A. Sandoval, B. Hona, Segev BenZvi, J. C. Díaz-Vélez, Vincent Marandon, H. Fleischhack, Michael Schneider, J. Lundeen, Mehr Nisa, K. Engel, Vardan Baghmanyan, F. Salesa Greus, Nissim Fraija, K. P. Arunbabu, A. L. Longinotti, M. Mostafá, J. A. Goodman, M. Durocher, A. Jardin-Blicq, C. De León, Andrea Albert, M. Newbold, U. Cotti, Brenda Dingus, J. P. Harding, J. Martínez-Castro, Alejandro Lara, A. Peisker, E. Moreno, Amid Nayerhoda, Daniel Rosa-Gonzalez, Michael DuVernois, A. Carramiñana, Y. Pérez Araujo, H. León Vargas, R. Diaz Hernandez, E. Willox, P. Miranda-Romagnoli, John Matthews, A. Galván-Gámez, E. De la Fuente, D. Avila Rojas, Oscar Martinez, G. Luis-Raya, Sabrina Casanova, V. Joshi, J.C. Arteaga-Velázquez, P. Hüntemeyer, W. H. Lee, Ke Fang, R. Torres-Escobedo, T. Capistrán, J. Cotzomi, F. Ureña-Mena, F. Garfias, Maria Magdalena González, Hongyan Zhou, Filiberto Hueyotl-Zahuantitla, Ruben Alfaro, C. D. Rho, R. W. Springer, H. Salazar, C. Alvarez, D. Huang, K. Malone, E. G. Pérez-Pérez, and Jose Andres Garcia-Gonzalez
- Subjects
Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Photon ,010504 meteorology & atmospheric sciences ,Proton ,Molecular cloud ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Cosmic ray ,Astrophysics ,Radiation ,7. Clean energy ,01 natural sciences ,Galaxy ,13. Climate action ,Space and Planetary Science ,Observatory ,0103 physical sciences ,Physics::Accelerator Physics ,Astrophysics - High Energy Astrophysical Phenomena ,010303 astronomy & astrophysics ,Cherenkov radiation ,0105 earth and related environmental sciences - Abstract
The Earth is bombarded by ultra-relativistic particles, known as cosmic rays (CRs). CRs with energies up to a few PeV (=10$^{15}$ eV), the knee in the particle spectrum, are believed to have a Galactic origin. One or more factories of PeV CRs, or PeVatrons, must thus be active within our Galaxy. The direct detection of PeV protons from their sources is not possible since they are deflected in the Galactic magnetic fields. Hundred TeV $\gamma$-rays from decaying $\pi^0$, produced when PeV CRs collide with the ambient gas, can provide the decisive evidence of proton acceleration up to the knee. Here we report the discovery by the High Altitude Water Cherenkov (HAWC) observatory of the $\gamma$-ray source, HAWC~J1825-134, whose energy spectrum extends well beyond 200 TeV without a break or cutoff. The source is found to be coincident with a giant molecular cloud. The ambient gas density is as high as 700 protons/cm$^3$. While the nature of this extreme accelerator remains unclear, CRs accelerated to energies of several PeV colliding with the ambient gas likely produce the observed radiation., Comment: Accepted for publication in ApJL
- Published
- 2020