Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/44987
Title: Radio detections towards unidentified variable EGRET sources
Author: Paredes i Poy, Josep Maria
Martí Ribas, Josep
Ishwara-Chandra, C. H.
Torres, Diego F.
Romero, Gustavo E.
Combi, J. A.
Bosch i Ramon, Valentí
Muñoz-Arjonilla, A. J.
Sánchez-Sutil, J. R.
Keywords: Quàsars
Radiofonts
Radioastronomia
Astronomia de raigs gamma
Telescopis espacials
Quasars
Radio sources (Astronomy)
Radio astronomy
Gamma ray astronomy
Space telescopes
Issue Date: 2008
Publisher: Springer Verlag
Abstract: A considerable fraction of the -ray sources discovered with the Energetic Gamma-Ray Experiment Telescope (EGRET) remain unidentified. The EGRET sources that have been properly identified are either pulsars or variable sources at both radio and gamma-ray wavelengths. Most of the variable sources are strong radio blazars. However, some low galactic-latitude EGRET sources, with highly variable -ray emission, lack any evident counterpart according to the radio data available until now. Aims. The primary goal of this paper is to identify and characterise the potential radio counterparts of four highly variable -ray sources in the galactic plane through mapping the radio surroundings of the EGRET confidence contours and determining the variable radio sources in the field whenever possible. Methods. We have carried out a radio exploration of the fields of the selected EGRET sources using the Giant Metrewave Radio Telescope (GMRT) interferometer at 21 cm wavelength, with pointings being separated by months. Results. We detected a total of 151 radio sources. Among them, we identified a few radio sources whose flux density has apparently changed on timescales of months. Despite the limitations of our search, their possible variability makes these objects a top-priority target for multiwavelength studies of the potential counterparts of highly variable, unidentified gamma-ray sources.
Note: Versió postprint del document publicat a: http://dx.doi.org/10.1051/0004-6361:20078299
It is part of: Astronomy and Astrophysics, 2008, vol. 482, num. 1, p. 247-253
Related resource: http://dx.doi.org/10.1051/0004-6361:20078299
URI: http://hdl.handle.net/2445/44987
ISSN: 0004-6361
Appears in Collections:Articles publicats en revistes (Física Quàntica i Astrofísica)

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