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J/A+A/482/247       Radio detections of 3G sources           (Paredes+, 2008)

Radio detections towards unidentified variable EGRET sources. Paredes J.M., Marti J., Ishwara-Chandra C.H., Torres D.F., Romero G.E., Combi J.A., Bosch-Ramon V., Munoz-Arjonilla A.J., Sanchez-Sutil J.R. <Astron. Astrophys. 482, 247 (2008)> =2008A&A...482..247P
ADC_Keywords: Gamma rays ; Radio sources ; Morphology Keywords: radio continuum: stars - gamma rays: observations - X-rays: binaries Abstract: A considerable fraction of the gamma-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 gamma-ray emission, lack any evident counterpart according to the radio data available until now. The primary goal of this paper is to identify and characterise the potential radio counterparts of four highly variable gamma-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. 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. Description: This table contains information about all radio sources detected with the Giant Metrewave Radio Telescope (GMRT) of the National Centre for Radio Astrophysics (NCRA) in Khodad (India) towards unidentified variable EGRET sources. The observations were carried out at 1.4 GHz (21 cm wavelength) during February 23 and April 19, 2005. The observed fields, each about one square deg, were those corresponding to the EGRET sources 3EG J1735-1500, 3EG J1746-1001, 3EG J1810-1032 and 3EG J1904-1124. Values given were determined by fitting sources with elliptical Gaussians. Uncertainties first quoted for the peak and integrated flux density are based on the formal errors of the fit and allow the reliability of the detection to be judged. However, they do not contain the error contribution due to primary beam correction as a function of angular distance to the phase centre. An estimate of the combined error, including primary beam correction, is separately given. A variability index has been also computed but no value is shown when an unrealiable result is suspected (see paper for details). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table4.dat 115 151 List of GMRT sources detected
See also: J/ApJS/123/79 : Third EGRET catalog (3EG) (Hartman+, 1999) Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 16 A16 --- Name GMRT source name 18- 19 A2 --- Flag Flag (1) 21- 22 I2 h RAh Right ascension (J2000) 24- 25 I2 min RAm Right ascension (J2000) 27- 32 F6.3 s RAs Right ascension (J2000) 34- 38 F5.3 s e_RAs Error in right ascension 40 A1 --- DE- Declination sign (J2000) 41- 42 I2 deg DEd Declination (J2000) 44- 45 I2 arcmin DEm Declination (J2000) 47- 51 F5.2 arcsec DEs Declination (J2000) 53- 56 F4.2 arcsec e_DEs Error in declination 58- 62 F5.1 mJy Speak Peak flux density at 21cm (in mJy/beam) 64- 66 F3.1 mJy e_Speak Error in peak flux density (in mJy/beam) 69- 73 F5.1 mJy Sint Integrated flux density at 21cm 75- 77 F3.1 mJy e_Sint Error in integrated flux density 79- 83 F5.2 arcsec a Apparent angular size (major axis) 85- 88 F4.2 arcsec b Apparent angular size (minor axis) 90- 94 F5.1 deg PA Position angle of major axis 96- 99 F4.1 arcmin Theta Angular distance to phase centre 101-105 F5.1 mJy ceSpeak Combined error in peak flux density (in mJy/beam) 107-111 F5.1 mJy ceSint Combined error in integrated flux density 113-115 F3.1 --- Var ? Variability index (2)
Note (1): Flag as follows: D = Component of an apparent double source (separation less than 45") MD = Marginally resolved double source T = Component of an apparent triple source V = Candidate variable radio source * = Extended component of a radio galaxy western lobe Note (2): No value given when an unreliable result is suspected.
Acknowledgements: Josep Marti Ribas, jmarti(at)ujaen.es
(End) Patricia Vannier [CDS] 05-Mar-2008
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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