We report on the VERITAS discovery of very high energy (VHE) gamma-ray emission above 200GeV from the high-frequency-peaked BL Lac (HBL) object RXJ0648.7+1516 (GBJ0648+1516), associated with 1FGLJ0648.8+1516. The photon spectrum above 200GeV is fitted by a power law dN/dE = F 0(E/E 0)-Γ with a photon index Γ of 4.4 ± 0.8stat± 0.3syst and a flux normalization F 0 of (2.3± 0.5stat± 1.2sys) × 10-11TeV-1cm-2 s-1 with E 0 = 300GeV. No VHE variability is detected during VERITAS observations of RXJ0648.7+1516 between 2010 March 4 and April 15. Following the VHE discovery, the optical identification and spectroscopic redshift were obtained using the Shane 3 m Telescope at the Lick Observatory, showing the unidentified object to be a BL Lac type with a redshift of z = 0.179. Broadband multiwavelength observations contemporaneous with the VERITAS exposure period can be used to subclassify the blazar as an HBL object, including data from the MDM observatory, Swift-UVOT, and X-Ray Telescope, and continuous monitoring at photon energies above 1GeV from the Fermi Large Area Telescope (LAT). We find that in the absence of undetected, high-energy rapid variability, the one-zone synchrotron self-Compton (SSC) model overproduces the high-energy gamma-ray emission measured by the Fermi-LAT over 2.3 years. The spectral energy distribution can be parameterized satisfactorily with an external-Compton or lepto-hadronic model, which have two and six additional free parameters, respectively, compared to the one-zone SSC model. © 2011. The American Astronomical Society. All rights reserved.

Aliu, E., Aune, T., Beilicke, M., Benbow, W., Bottcher, M., Bouvier, A., et al. (2011). Multiwavelength observations of the previously unidentified blazar RX J0648.7+1516. THE ASTROPHYSICAL JOURNAL, 742(2) [10.1088/0004-637X/742/2/127].

Multiwavelength observations of the previously unidentified blazar RX J0648.7+1516

Fumagalli M.;
2011

Abstract

We report on the VERITAS discovery of very high energy (VHE) gamma-ray emission above 200GeV from the high-frequency-peaked BL Lac (HBL) object RXJ0648.7+1516 (GBJ0648+1516), associated with 1FGLJ0648.8+1516. The photon spectrum above 200GeV is fitted by a power law dN/dE = F 0(E/E 0)-Γ with a photon index Γ of 4.4 ± 0.8stat± 0.3syst and a flux normalization F 0 of (2.3± 0.5stat± 1.2sys) × 10-11TeV-1cm-2 s-1 with E 0 = 300GeV. No VHE variability is detected during VERITAS observations of RXJ0648.7+1516 between 2010 March 4 and April 15. Following the VHE discovery, the optical identification and spectroscopic redshift were obtained using the Shane 3 m Telescope at the Lick Observatory, showing the unidentified object to be a BL Lac type with a redshift of z = 0.179. Broadband multiwavelength observations contemporaneous with the VERITAS exposure period can be used to subclassify the blazar as an HBL object, including data from the MDM observatory, Swift-UVOT, and X-Ray Telescope, and continuous monitoring at photon energies above 1GeV from the Fermi Large Area Telescope (LAT). We find that in the absence of undetected, high-energy rapid variability, the one-zone synchrotron self-Compton (SSC) model overproduces the high-energy gamma-ray emission measured by the Fermi-LAT over 2.3 years. The spectral energy distribution can be parameterized satisfactorily with an external-Compton or lepto-hadronic model, which have two and six additional free parameters, respectively, compared to the one-zone SSC model. © 2011. The American Astronomical Society. All rights reserved.
Si
Articolo in rivista - Articolo scientifico
Scientifica
gamma rays: galaxies;
English
Aliu, E., Aune, T., Beilicke, M., Benbow, W., Bottcher, M., Bouvier, A., et al. (2011). Multiwavelength observations of the previously unidentified blazar RX J0648.7+1516. THE ASTROPHYSICAL JOURNAL, 742(2) [10.1088/0004-637X/742/2/127].
Aliu, E; Aune, T; Beilicke, M; Benbow, W; Bottcher, M; Bouvier, A; Bradbury, S; Buckley, J; Bugaev, V; Cannon, A; Cesarini, A; Ciupik, L; Connolly, M; Cui, W; Decerprit, G; Dickherber, R; Duke, C; Errando, M; Falcone, A; Feng, Q; Finnegan, G; Fortson, L; Furniss, A; Galante, N; Gall, D; Gillanders, G; Godambe, S; Griffin, S; Grube, J; Gyuk, G; Hanna, D; Hivick, B; Holder, J; Huan, H; Hughes, G; Hui, C; Humensky, T; Kaaret, P; Karlsson, N; Kertzman, M; Kieda, D; Krawczynski, H; Krennrich, F; Maier, G; Majumdar, P; Mcarthur, S; Mccann, A; Moriarty, P; Mukherjee, R; Nelson, T; Ong, R; Orr, M; Otte, A; Park, N; Perkins, J; Pichel, A; Pohl, M; Prokoph, H; Quinn, J; Ragan, K; Reyes, L; Reynolds, P; Roache, E; Rose, H; Ruppel, J; Saxon, D; Sembroski, G; Skole, C; Smith, A; Staszak, D; Teisic, G; Theiling, M; Thibadeau, S; Tsurusaki, K; Tyler, J; Varlotta, A; Vassiliev, V; Wakely, S; Weekes, T; Weinstein, A; Williams, D; Zitzer, B; Ciprini, S; Fumagalli, M; Kaplan, K; Paneque, D; Prochaska, J
File in questo prodotto:
File Dimensione Formato  
1110.5949.pdf

accesso aperto

Tipologia di allegato: Author’s Accepted Manuscript, AAM (Post-print)
Dimensione 324.76 kB
Formato Adobe PDF
324.76 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/10281/297846
Citazioni
  • Scopus 28
  • ???jsp.display-item.citation.isi??? 28
Social impact