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Date and Time of the Query: 2019-04-20 T21:09:49 PDT
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For refcode 1993A&AS..100..263O:
Retrieve 422 NED objects in this reference.
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Copyright by European Southern Observatory (ESO). Reproduced by permission
1993A&AS..100..263O Optical positions and 327 MHz flux-densities of UGC galaxies in selected Westerbork fields C. Oly and F.P. Israel Sterrewacht Leiden, Postbus 9513,2300 RA Leiden, The Netherlands Received October 2; accepted November 14, 1992 Abstract. - We present accurate optical positions of 421 UGC galaxies which we used to search thirty 92 cm (326 MHz) WSRT fields observed for other purposes for emission from these galaxies. Good 92 cm flux- densities were obtained for 140 galaxies, marginal flux-densities for 71 galaxies and upper limits for 210 galaxies. Thus, we detected half of all UGC galaxies in the observed fields. For 35 galaxies we have determined spectral indices in the decimeter wavelength range. The mean spectral index for spiral galaxies ({alpha} = 0.72 +/- 0.03) is very similar to that of elliptical galaxies ({alpha} = 0.64 +/- 0.10). The four multiple systems in the sample have a much flatter spectral index ({alpha} = - 0.21 +/- 0.07) which suggests the presence of a significant thermal component in their total radio emission. The monochromatic radio luminosity of the detected galaxies is sharply peaked between L_92_ = 10^22^ and 10^23^ W Hz^-1^. Comparison with IRAS results show that about half of the galaxies detected at radio wavelengths are detected in the far-infrared (i.e. a quarter of all galaxies). Virtually no E/S0 galaxies were seen. The correlation of 100 micron emission with optical brightness is significantly better than the correlation of radio with optical brightness for the spiral galaxies in the sample. Both relations are approximately linear. Almost all galaxies brighter than m_p_ = 14.0 mag were detected both in the radio and the infrared. The data suggest that some spiral galaxies are anomalously weak in the infrared as compared with their radio brightness, but this needs confirmation. Key words: galaxies: general - radio - infrared
Retrieve 422 NED objects in this reference.
Please click here for ADS abstract

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