VERITAS and Fermi-LAT Observations of TeV Gamma-Ray Sources Discovered by HAWC in the 2HWC Catalog

Abeysekara, A. U.; Archer, A.; Benbow, W.; Bird, R.; Brose, R.; Buchovecky, M.; Buckley, J. H.; Bugaev, V.; Chromey, A. J.; Connolly, M. P.; Cui, W.; Daniel, M. K.; Falcone, A.; Feng, Q.; Finley, J. P.; Fortson, L.; Furniss, A.; Hutten, M.; Hanna, D.; Hervet, O.; Holder, J.; Hughes, G.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kar, P.; Kertzman, M.; Kieda, D.; Krause, M.; Krennrich, F.; Kumar, S.; Lang, M. J.; Lin, T. T. Y.; Mcarthur, S.; Moriarty, P.; Mukherjee, R.; O'Brien, S.; Ong, R. A.; Otte, A. N.; Park, N.; Petrashyk, A.; Pohl, M.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Rulten, C.; Sadeh, I.; Santander, M.; Sembroski, G. H.; Shahinyan, K.; Sushch, I.; Tyler, J.; Wakely, S. P.; Weinstein, A.; Wells, R. M.; Wilcox, P.; Wilhelm, A.; Williams, D. A.; Williamson, T. J.; Zitzer, B.; Abdollahi, S.; Ajello, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Berenji, B.; Bissaldi, E.; Blandford, R. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bruel, P.; Buehler, R.; Cameron, R. A.; Caputo, R.; Caraveo, P. A.; Castro, D.; Cavazzuti, E.; Charles, E.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Costantin, D.; Cutini, S.; D'Ammando, F.; Palma, F. D.; Lalla, N. D.; Mauro, M. D.; Venere, L. D.; Dominguez, A.; Favuzzi, C.; Fegan, S. J.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Giroletti, M.; Green, D.; Grenier, I. A.; Guillemot, L.; Guiriec, S.; Hays, E.; Hewitt, J. W.; Horan, D.; Johannesson, G.; Kensei, S.; Kuss, M.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J. D.; Maldera, S.; Mazziotta, M. N.; Mcenery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Ojha, R.; Omodei, N.; Orienti, M.; Orlando, E.; Palatiello, M.; Paliya, V. S.; Paneque, D.; Perkins, J. S.; Persic, M.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Porter, T. A.; Principe, G.; Raino, S.; Rando, R.; Rani, B.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Sgro, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Thayer, J. B.; Thompson, D. J.; Torres, D. F.; Tosti, G.; Troja, E.; Valverde, J.; Vianello, G.; Vogel, M.; Wood, K.; Yassine, M.; Alfaro, R.; Alvarez, C.; Alvarez, J. D.; Arceo, R.; Arteaga-Velazquez, J. C.; Rojas, D. A.; Solares, H. A. A.; Becerril, A.; Belmont-Moreno, E.; Benzvi, S. Y.; Bernal, A.; Braun, J.; Brisbois, C.; Caballero-Mora, K. S.; Capistran, T.; Carraminana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Cotzomi, J.; De Leon, S. C.; Leon, C. D.; Fuente, E. D. L.; Dichiara, S.; Dingus, B. L.; Duvernois, M. A.; Diaz-Velez, J. C.; Engel, K.; Enriquez-Rivera, O.; Fiorino, D. W.; Fleischhack, H.; Fraija, N.; Garcia-Gonzalez, J. A.; Garfias, F.; Munoz, A. G.; Gonzalez, M. M.; Goodman, J. A.; Hampel-Arias, Z.; Harding, J. P.; Hernandez, S.; Hernandez-Almada, A.; Hona, B.; Hueyotl-Zahuantitla, F.; Hui, C. M.; Huntemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Lara, A.; Lauer, R. J.; Lee, W. H.; Lennarz, D.; Vargas, H. L.; Linnemann, J. T.; Longinotti, A. L.; Luis-Raya, G.; Luna-Garcia, R.; Lopez-Coto, R.; Malone, K.; Marinelli, S. S.; Martinez, O.; Martinez-Castellanos, I.; Martinez-Castro, J.; Martinez-Huerta, H.; Matthews, J. A.; Miranda-Romagnoli, P.; Moreno, E.; Mostafa, M.; Nayerhoda, A.; Nellen, L.; Newbold, M.; Nisa, M. U.; Noriega-Papaqui, R.; Pelayo, R.; Pretz, J.; Perez-Perez, E. G.; Ren, Z.; Rho, C. D.; Riviere, C.; Rosa-Gonzalez, D.; Rosenberg, M.; Ruiz-Velasco, E.; Salazar, H.; Greus, F. S.; Sandoval, A.; Schneider, M.; Arroyo, M. S.; Sinnis, G.; Smith, A. J.; Springer, R. W.; Surajbali, P.; Taboada, I.; Tibolla, O.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Villasenor, L.; Weisgarber, T.; Westerhoff, S.; Wisher, I. G.; Wood, J.; Yapici, T.; Yodh, G.; Zepeda, A.; Zhou, H.

doi:10.3847/1538-4357/aade4e

The High Altitude Water Cherenkov (HAWC) collaboration recently published their 2HWC catalog, listing 39 very high energy (VHE; >100 GeV) gamma-ray sources based on 507 days of observation. Among these, 19 sources are not associated with previously known teraelectronvolt (TeV) gamma-ray sources. We have studied 14 of these sources without known counterparts with VERITAS and Fermi-LAT. VERITAS detected weak gamma-ray emission in the 1 TeV-30 TeV band in the region of DA 495, a pulsar wind nebula coinciding with 2HWC J1953+294, confirming the discovery of the source by HAWC. We did not find any counterpart for the selected 14 new HAWC sources from our analysis of Fermi-LAT data for energies higher than 10 GeV. During the search, we detected gigaelectronvolt (GeV) gamma-ray emission coincident with a known TeV pulsar wind nebula, SNR G54.1+0.3 (VER J1930+188), and a 2HWC source, 2HWC J1930+188. The fluxes for isolated, steady sources in the 2HWC catalog are generally in good agreement with those measured by imaging atmospheric Cherenkov telescopes. However, the VERITAS fluxes for SNR G54.1+0.3, DA 495, and TeV J2032+4130 are lower than those measured by HAWC, and several new HAWC sources are not detected by VERITAS. This is likely due to a change in spectral shape, source extension, or the influence of diffuse emission in the source region.

VERITAS and Fermi-LAT Observations of TeV Gamma-Ray Sources Discovered by HAWC in the 2HWC Catalog / Abeysekara, A.U., Archer, A., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Buckley, J.H., Bugaev, V., Chromey, A.J., Connolly, M.P., Cui, W., Daniel, M.K., Falcone, A., Feng, Q., Finley, J.P., Fortson, L., Furniss, A., Hutten, M., Hanna, D., Hervet, O., et al.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - STAMPA. - 866:1(2018). [10.3847/1538-4357/aade4e]