Abstract
LS I +61 303 is one of only a few high-mass X-ray binaries currently detected at high significance in very high energy gamma-rays. The system was observed over several orbital cycles ( between 2006 September and 2007 February) with the VERITAS array of imaging air Cerenkov telescopes. A signal of gamma-rays with energies above 300 GeV is found with a statistical significance of 8.4 standard deviations. The detected flux is measured to be strongly variable; the maximum flux is found during most orbital cycles at apastron. The energy spectrum for the period of maximum emission can be characterized by a power law with a photon index of Gamma = 2.40 + - 0.16(stat) + - 0.2(sys) and a flux above 300 GeV corresponding to 15% - 20% of the flux from the Crab Nebula.
| Original language | English (Ireland) |
|---|---|
| Number of pages | 6 |
| Journal | Astrophysical Journal |
| Volume | 679 |
| Publication status | Published - 1 Jun 2008 |
Authors (Note for portal: view the doc link for the full list of authors)
- Authors
- Acciari, VA,Beilicke, M,Blaylock, G,Bradbury, SM,Buckley, JH,Bugaev, V,Butt, Y,Byrum, KL,Celik, O,Cesarini, A,Ciupik, L,Chow, YCK,Cogan, P,Colin, P,Cui, W,Daniel, MK,Duke, C,Ergin, T,Falcone, AD,Fegan, SJ,Finley, JP,Fortin, P,Fortson, LF,Gall, D,Gibbs, K,Gillanders, GH,Grube, J,Guenette, R,Hanna, D,Hays, E,Holder, J,Horan, D,Hughes, SB,Hui, CM,Humensky, TB,Kaaret, P,Kieda, DB,Kildea, J,Konopelko, A,Krawczynski, H,Krennrich, F,Lang, MJ,LeBohec, S,Lee, K,Maier, G,McCann, A,McCutcheon, M,Millis, J,Moriarty, P,Mukherjee, R,Nagai, T,Ong, RA,Pandel, D,Perkins, JS,Pizlo, F,Pohl, M,Quinn, J,Ragan, K,Reynolds, PT,Rose, HJ,Schroedter, M,Sembroski, GH,Smith, AW,Steele, D,Swordy, SP,Toner, JA,Valcarcel, L,Vassiliev, VV,Wagner, R,Wakely, SP,Ward, JE,Weekes, TC,Weinstein, A,White, RJ,Williams, DA,Wisse