Results 41 to 50 of about 638,354 (389)

Point Sources of GeV Gamma Rays [PDF]

The Astrophysical Journal, 1997
A catalog of c-ray sources based on photons with energies greater than 1 GeV has been developed from observations taken by the EGRET instrument of the Compton Gamma Ray Observatory. The data are taken from the 4.5 yr of observation available in the public data archives. We emphasize sources that are detected using the entire database, without regard
R. C. Lamb, D. J. Macomb, D. J. Macomb
openaire   +4 more sources

Radio Counterparts of Gamma-Ray Sources in the Cygnus Region [PDF]

The Astrophysical Journal Supplement Series, 2021
Abstract The view of the gamma-ray universe is being continuously expanded by space high-energy (HE) and ground-based very-high-energy (VHE) observatories. Yet, the angular resolution limitation still precludes a straightforward identification of these gamma-ray emitting sources.
N. L. Isequilla, Paula Benaglia, Marcelo E. Colazo, Josep M. Paredes, Huib Intema, Huib Intema, C. H. Ishwara-Chandra   +6 more
openaire   +7 more sources

A correlation between hard gamma-ray sources and cosmic voids along the line of sight [PDF]

, 2014
We estimate the galaxy density along lines of sight to hard extragalactic gamma-ray sources by correlating source positions on the sky with a void catalog based on the Sloan Digital Sky Survey (SDSS).
A. Furniss, P. Sutter, J. Primack, A. Domínguez   +3 more
semanticscholar   +1 more source

CATACLYSMIC VARIABLES AND GAMMA-RAY SOURCES [PDF]

EAS Publications Series, 2013
The cataclysmic variables are associated with high energy events and probably many of them could be potential gamma-ray sources. Up to now Fermi-LAT detected 3 gamma-ray transients, which belong to CVs and related objects: V407 Cyg, N Sco 2012 and N Mon 2012 = V959 Mon. We present the first multicolour observations of the slow classical nova V959 Mon.
Sergey Yu. Shugarov, Sergey Yu. Shugarov, Drahomir Chochol, E. P. Pavlenko, Viktor Malanushenko   +4 more
openaire   +2 more sources

A Search for Blazar-Like Radio-Loud Narrow-Line Seyfert 1 Galaxies

Galaxies, 2017
We report the results of an observational program to investigate the gamma-ray and optical variability properties of the vRL NLSY1 galaxies listed in the Yuan et al. sample. We have identified 17 members of the Yuan et al. sample possibly associated with
Hugh R. Miller, Jeremy D. Maune, Joseph R. Eggen, Clay S. Turner, Elizabeth C. Ferrara, Diana O. Gudkova, Amy M. Battles   +6 more
doaj   +1 more source

Second AGILE catalogue of gamma-ray sources [PDF]

Astronomy & Astrophysics, 2019
Aims. We present the second AGILE–GRID catalogue (2AGL) ofγ-ray sources in the energy range 100 MeV–10 GeV.Methods. With respect to previous AGILE–GRID catalogues, the current 2AGL catalogue is based on the first 2.3 years of science data from the AGILE mission (the so-called pointing mode) and incorporates more data and several analysis improvements ...
A. Pellizzoni, L. Baroncelli, Francesco Longo, A. Giuliani, Alessio Aboudan, Fulvio Gianotti, Maura Pilia, A. Rappoldi, M. Trifoglio, M. Tavani, Fabrizio Lucarelli, Fabrizio Lucarelli, G. Piano, N. Parmiggiani, A. Argan, M. Giusti, S. Vercellone, A. W. Chen, C. Pittori, C. Pittori, Louis Antonelli, Andrea Bulgarelli, Paolo Giommi, P. W. Cattaneo, M. Cardillo, I. Donnarumma, I. Donnarumma, Alessio Trois, F. Verrecchia, F. Verrecchia, Valentina Fioretti, Andrea Zoli   +31 more
openaire   +5 more sources

BLAZARS AS ULTRA-HIGH-ENERGY COSMIC-RAY SOURCES: IMPLICATIONS FOR TeV GAMMA-RAY OBSERVATIONS [PDF]

, 2011
The spectra of BL Lac objects and Fanaroff–Riley I radio galaxies are commonly explained by the one-zone leptonic synchrotron self-Compton (SSC) model. Spectral modeling of correlated multiwavelength data gives the comoving magnetic field strength, the ...
K. Murase, C. Dermer, H. Takami, G. Migliori   +3 more
semanticscholar   +1 more source

A stacking method to study the gamma-ray emission of source samples based on the co-adding of Fermi LAT count maps [PDF]

, 2012
We present a stacking method that makes use of co-added maps of gamma-ray counts produced from data taken with the Fermi Large Area Telescope. Sources with low integrated gamma-ray fluxes that are not detected individually may become detectable when ...
Farnier, C., Huber, B., Manalaysay, A., Straumann, U., Walter, R.   +4 more
core   +1 more source

NEW ASSOCIATIONS OF GAMMA-RAY SOURCES FROM THE FERMI SECOND SOURCE CATALOG [PDF]

, 2014
We present the results of an all-sky radio survey between 5 and 9 GHz of sky areas surrounding all unassociated γ-ray objects listed in the Fermi Large Area Telescope Second Source Catalog (2FGL).
F. Schinzel, L. Petrov, G. Taylor, E. Mahony, P. Edwards, Y. Kovalev   +5 more
semanticscholar   +1 more source

Near-infrared and gamma-ray monitoring of TANAMI gamma-ray bright sources [PDF]

Astronomy & Astrophysics, 2013
Spectral energy distribution and its variability are basic tools for understanding the physical processes operating in active galactic nuclei (AGN). In this paper we report the results of a one-year near infra red (NIR) and optical monitoring of a sample of 22 AGN known to be gamma-ray emitters, aimed at discovering correlations between optical and ...
Roberto Nesci, Roberto Nesci, Gino Tosti, Tapio Pursimo, Roopesh Ojha, Roopesh Ojha, Matthias Kadler   +6 more
openaire   +5 more sources