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| Paper: |
Decametric AGNs: FIRST and NVSS Maps and Radio Spectra |
| Volume: |
284, AGN Surveys, IAU Colloquium 184 |
| Page: |
306 |
| Authors: |
Verkhodanova, Natalia V.; Verkhodanov, Oleg V.; Andernach, Heinz |
| Abstract: |
We describe a method of plotting continuous spectra for radio sources on the basis of entries of various source catalogues in comparatively large error boxes around a given sky position. Sources from the UTR-2 catalogue (Braude et al., 1978-1994), observed at decametric wavelengths (10?25 MHz) with an antenna beam of about 40', were cross-identified with entries from other radio catalogues at higher frequencies. Using the CATS database we extracted all sources within 40' around UTR positions to find candidate identifications. The spectrum for each source was fitted with a set of curves using the least squares method to find the best fit. We preferentially selected radio counterparts whose radio spectrum extrapolated to low frequencies matched the UTR decametric flux densities, and whose coordinates were close to the gravity center of UTR positions. Identifications with objects from optical, X-ray and infrared catalogues, as well as a subsample of UTR sources with ultra-steep spectrum are presented. NVSS and FIRST images of identified objects are discussed. |
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