Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E > 100 GeV) γ-ray sources. In this work, we present the analysis results of a sample of 114 undetected objects. The observations constitute a total live-time of ∼570 hr. The sample includes several unidentified Fermi-Large Area Telescope (LAT) sources (located at high Galactic latitude) as well as all the sources from the second Fermi-LAT catalog that are contained within the field of view of the VERITAS observations. We have also performed optical spectroscopy measurements in order to estimate the redshift of some of these blazars that do not have spectroscopic distance estimates. We present new optical spectra from the Kast instrument on the Shane telescope at the Lick observatory for 18 blazars included in this work, which allowed for the successful measurement or constraint on the redshift of four of them. For each of the blazars included in our sample, we provide the flux upper limit in the VERITAS energy band. We also study the properties of the significance distributions and we present the result of a stacked analysis of the data set, which shows a 4σ excess. © 2016. The American Astronomical Society. All rights reserved..
Documento: | Artículo |
Título: | UPPER LIMITS from FIVE YEARS of BLAZAR OBSERVATIONS with the VERITAS CHERENKOV TELESCOPES |
Autor: | Archambault, S.; Archer, A.; Benbow, W.; Bird, R.; Biteau, J.; Buchovecky, M.; Buckley, J.H.; Bugaev, V.; Byrum, K.; Cerruti, M.; Chen, X.; Ciupik, L.; Connolly, M.P.; Cui, W.; Eisch, J.D.; Errando, M.; Falcone, A.; Feng, Q.; Finley, J.P.; Fleischhack, H.; Fortin, P.; Fortson, L.; Furniss, A.; Gillanders, G.H.; Griffin, S.; Grube, J.; Gyuk, G.; Hütten, M.; Håkansson, N.; Hanna, D.; Holder, J.; Humensky, T.B.; Johnson, C.A.; Kaaret, P.; Kar, P.; Kelley-Hoskins, N.; Kertzman, M.; Kieda, D.; Krause, M.; Krennrich, F.; Kumar, S.; Lang, M.J.; Maier, G.; McArthur, S.; McCann, A.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nguyen, T.; Nieto, D.; O'Faoláin De Bhróithe, A.; Ong, R.A.; Otte, A.N.; Park, N.; Perkins, J.S.; Pichel, A.; Pohl, M.; Popkow, A.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P.T.; Richards, G.T.; Roache, E.; Rovero, A.C.; Santander, M.; Sembroski, G.H.; Shahinyan, K.; Smith, A.W.; Staszak, D.; Telezhinsky, I.; Tucci, J.V.; Tyler, J.; Vincent, S.; Wakely, S.P.; Weiner, O.M.; Weinstein, A.; Williams, D.A.; Zitzer, B.; Fumagalli, M.; Prochaska, J.X. |
Filiación: | Physics Department, McGill University, Montreal, QC H3A 2T8, Canada Department of Physics, Washington University, St. Louis, MO 63130, United States Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645, United States School of Physics, University College Dublin, Belfield, Dublin 4, Ireland Santa Cruz Institute for Particle Physics, University of California, Department of Physics, Santa Cruz, CA 95064, United States Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, United States Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States Institute of Physics and Astronomy, University of Potsdam, Potsdam-Golm, D-14476, Germany DESY, Platanenallee 6, Zeuthen, D-15738, Germany Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605, United States School of Physics, National University of Ireland Galway, University Road, Galway, Ireland Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907, United States Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, United States Department of Physics and Astronomy, Barnard College, Columbia UniversityNY 10027, United States Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802, United States School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, United States Department of Physics, California State University - East Bay, Hayward, CA 94542, United States Department of Physics and Astronomy, Bartol Research Institute, University of Delaware, Newark, DE 19716, United States Physics Department, Columbia University, New York, NY 10027, United States Department of Physics and Astronomy, University of Iowa, Van Allen Hall, Iowa City, IA 52242, United States Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, United States Department of Physics and Astronomy, DePauw University, Greencastle, IN 46135-0037, United States School of Physics and Center for Relativistic Astrophysics, Georgia Institute of Technology, 837 State Street NW, Atlanta, GA 30332-0430, United States Enrico Fermi Institute, University of Chicago, Chicago, IL 60637, United States N.A.S.A./Goddard Space-Flight Center, Greenbelt, CODE, MD 20771, United States Instituto de Astronomia y Fisica Del Espacio, Casilla de Correo 67 - Sucursal 28, Ciudad Autónoma de Buenos Aires, C1428ZAA, Argentina Department of Physical Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland University of Maryland, College Park/NASA GSFC, College Park, MD 20742, United States Institute for Computational Cosmology, Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham, DH1 3LE, United Kingdom Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, United States |
Palabras clave: | BL Lacertae objects: general; galaxies: active; gamma rays: galaxies; radiation mechanisms: non-thermal |
Año: | 2016 |
Volumen: | 151 |
Número: | 6 |
DOI: | http://dx.doi.org/10.3847/0004-6256/151/6/142 |
Título revista: | Astronomical Journal |
Título revista abreviado: | Astron. J. |
ISSN: | 00046256 |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046256_v151_n6_p_Archambault |