Статья

BLAZARS IN THE <i>FERMI</i> ERA: THE OVRO 40 m TELESCOPE MONITORING PROGRAM

Joseph L. RichardsCahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USAW. Max-MoerbeckCahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USAV. PavlidouCahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USAO. G. KingCahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USAT. J. PearsonCahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USAA. C. S. ReadheadCahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USAR. ReevesCahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USAM. C. ShepherdCahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USAM. A. StevensonCahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USAL. WeintraubCahill Laboratory of Astronomy and Astrophysics, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USALars FuhrmannMax-Planck-Institut-für-Radioastronomie, Auf dem Hügel 69, 53121 Bonn, GermanyE. AngelakisMax-Planck-Institut-für-Radioastronomie, Auf dem Hügel 69, 53121 Bonn, GermanyJ. A. ZensusMax-Planck-Institut-für-Radioastronomie, Auf dem Hügel 69, 53121 Bonn, GermanyStephen E. HealeyDepartment of Physics, Stanford University, Stanford, CA 94305, USARoger W. RomaniDepartment of Physics, Stanford University, Stanford, CA 94305, USAMichael S. ShawDepartment of Physics, Stanford University, Stanford, CA 94305, USAKeith GraingeAstrophysics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Ave, Cambridge CB3 0HE, UKM. BirkinshawH. H. Wills Physics Laboratory, University of Bristol, Tyndall Ave, Bristol BS8 1TL, UKKaty LancasterH. H. Wills Physics Laboratory, University of Bristol, Tyndall Ave, Bristol BS8 1TL, UKD. M. WorrallH. H. Wills Physics Laboratory, University of Bristol, Tyndall Ave, Bristol BS8 1TL, UKGregory B. TaylorDepartment of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, USAGarret CotterDepartment of Astrophysics, University of Oxford, Keble Road, Oxford, OX1 3RH, UKRicardo BustosDepartamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile

2011en

ABI

Аннотация

The Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope provides an unprecedented opportunity to study gamma-ray blazars. To capitalize on this opportunity, beginning in late 2007, about a year before the start of LAT science operations, we began a large-scale, fast-cadence 15GHz radio monitoring program with the 40 m telescope at the Owens Valley Radio Observatory. This program began with the 1158 northern (δ &gt; -20°) sources from the Candidate Gamma-ray Blazar Survey and now encompasses over 1500 sources, each observed twice per week with about 4mJy (minimum) and 3% (typical) uncertainty. Here, we describe this monitoring program and our methods, and present radio light curves from the first two years (2008 and 2009). As a first application, we combine these data with a novel measure of light curve variability amplitude, the intrinsic modulation index, through a likelihood analysis to examine the variability properties of subpopulations of our sample. We demonstrate that, with high significance (6σ), gamma-ray-loud blazars detected by the LAT during its first 11 months of operation vary with almost a factor of two greater amplitude than do the gamma-ray-quiet blazars in our sample. We also find a significant (3σ) difference between variability amplitude in BL Lacertae objects and flat-spectrum radio quasars (FSRQs), with the former exhibiting larger variability amplitudes. Finally, low-redshift (z &lt; 1) FSRQs are found to vary more strongly than high-redshift FSRQs, with 3σ significance. These findings represent an important step toward understanding why some blazars emit gamma-rays while others, with apparently similar properties, remain silent. © 2011. The American Astronomical Society. All rights reserved..

Перевод пока недоступен

Идентификаторы

DOI: 10.1088/0067-0049/194/2/29

Цитирования и источники

Цитирований: 5Использованных источников: 0

Показатели — AkademScholar