%0 Electronic Article
%A Adams, C. B.
%A Bangale, P.
%A Benbow, W.
%A Buckley, J. H.
%A Chen, Y.
%A Christiansen, J. L.
%A Chromey, A. J.
%A Godoy, M. Escobar
%A Feldman, S.
%A Feng, Q.
%A Foote, J.
%A Fortson, L.
%A Furniss, A.
%A Hanlon, W.
%A Hervet, O.
%A Hinrichs, C. E.
%A Holder, J.
%A Hughes, Z.
%A Humensky, T. B.
%A Jin, W.
%A Kaaret, P.
%A Kertzman, M.
%A Kherlakian, M.
%A Kieda, D.
%A Kleiner, Tobias Kai
%A Korzoun, N.
%A Kumar, S.
%A Lang, M. J.
%A Lundy, M.
%A Maier, G.
%A Millard, M. J.
%A Moriarty, P.
%A Mukherjee, R.
%A Ning, W.
%A Ong, R. A.
%A Pohl, M.
%A Pueschel, E.
%A Quinn, J.
%A Rabinowitz, P. L.
%A Ragan, K.
%A Reynolds, P. T.
%A Ribeiro, D.
%A Roache, E.
%A Sadeh, I.
%A Saha, L.
%A Sembroski, G. H.
%A Shang, R.
%A Tak, D.
%A Talluri, A. K.
%A Tucci, J. V.
%A Valverde, J.
%A Williams, D. A.
%A Wong, S. L.
%A Woo, J.
%A Alfaro, R.
%A Alvarez, C.
%A Arteaga-Velázquez, J. C.
%A Rojas, D. Avila
%A Babu, R.
%A Belmont-Moreno, E.
%A Bernal, A.
%A Caballero-Mora, K. S.
%A Carramiñana, A.
%A Casanova, S.
%A Cotti, U.
%A Cotzomi, J.
%A De la Fuente, E.
%A de León, C.
%A Depaoli, D.
%A Desiati, P.
%A Di Lalla, N.
%A Hernandez, R. Diaz
%A DuVernois, M. A.
%A Engel, K.
%A Ergin, T.
%A Espinoza, C.
%A Fan, K. L.
%A Fraija, N.
%A Fraija, S.
%A García-González, J. A.
%A Garfias, F.
%A Muñoz, A. Gonzalez
%A González, M. M.
%A Goodman, J. A.
%A Groetsch, S.
%A Harding, J. P.
%A Hernandez-Cadena, S.
%A Herzog, I.
%A Huang, D.
%A Hueyotl-Zahuantitla, F.
%A Hüntemeyer, P.
%A Iriarte, A.
%A Kaufmann, S.
%A Lara, A.
%A Lee, J.
%A León Vargas, H.
%A Longinotti, A. L.
%A Luis-Raya, G.
%A Malone, K.
%A Martinez, O.
%A Martínez-Castro, J.
%A Matthews, J. A.
%A Miranda-Romagnoli, P.
%A Morales-Soto, J. A.
%A Moreno, E.
%A Araya, M.
%A Mostafá, M.
%A Najafi, M.
%A Nayerhoda, A.
%A Nellen, L.
%A Omodei, N.
%A Ponce, E.
%A Pérez-Pérez, E. G.
%A Rho, C. D.
%A Rosa-González, D.
%A Roth, M.
%A Salazar, H.
%A Sandoval, A.
%A Schneider, M.
%A Serna-Franco, J.
%A Smith, A. J.
%A Son, Y.
%A Springer, R. W.
%A Tibolla, O.
%A Tollefson, K.
%A Torres, I.
%A Torres-Escobedo, R.
%A Turner, R.
%A Ureña-Mena, F.
%A Varela, E.
%A Villaseñor, L.
%A Wang, X.
%A Wang, Z.
%A Watson, I. J.
%A Wu, H.
%A Yu, S.
%A Yun-Cárcamo, S.
%A Zhou, H.
%A Martin, M.
%A Mori, Kaya
%A Hailey, Charles J.
%A Safi-Harb, Samar
%A Zhang, And Shuo
%T HAWC, VERITAS, Fermi-LAT and XMM-Newton follow-up observations of the unidentified ultra-high-energy gamma-ray source LHAASO J2108+5157
%N arXiv:2508.01934
%M PUBDB-2025-05506
%M arXiv:2508.01934
%D 2025
%Z 12 pages, 4 figures, submitted to The Astrophysical Journal
%X We report observations of the ultra-high-energy gamma-ray source LHAASO J2108+5157, utilizing VERITAS, HAWC, Fermi-LAT, and XMM-Newton. VERITAS has collected  ∼  40 hours of data that we used to set ULs to the emission above 200 GeV. The HAWC data, collected over  ∼ 2400 days, reveal emission between 3 and 146 TeV, with a significance of 7.5 σ, favoring an extended source model. The best-fit spectrum measured by HAWC is characterized by a simple power-law with a spectral index of 2.45±0.11<sub>stat</sub>. Fermi-LAT analysis finds a point source with a very soft spectrum in the LHAASO J2108+5157 region, consistent with the 4FGL-DR3 catalog results. The XMM-Newton analysis yields a null detection of the source in the 2 - 7 keV band. The broadband spectrum can be interpreted as a pulsar and a pulsar wind nebula system, where the GeV gamma-ray emission originates from an unidentified pulsar, and the X-ray and TeV emission is attributed to synchrotron radiation and inverse Compton scattering of electrons accelerated within a pulsar wind nebula. In this leptonic scenario, our X-ray upper limit provides a stringent constraint on the magnetic field, which is  <~1.5 μG.
%F PUB:(DE-HGF)25
%9 Preprint
%R 10.3204/PUBDB-2025-05506
%U https://bib-pubdb1.desy.de/record/642351