30 GHz flux density measurements of the Caltech-Jodrell flat-spectrum sources with OCRA-p

TL;DR

This study measures 30-GHz flux densities of 293 flat-spectrum radio sources to analyze their spectral energy distributions and identify GPS sources, providing valuable data for understanding their astrophysical properties.

Contribution

It presents new 30-GHz flux density measurements for the CJF sample and identifies GPS sources and spectral characteristics, enhancing existing radio source data.

Findings

42 sources identified as GPS sources

17% of sources have rising spectra between 5 and 30 GHz

Data supports correlation of spectral properties with VLBI structures

Abstract

To measure the 30-GHz flux densities of the 293 sources in the Caltech-Jodrell Bank flat-spectrum (CJF) sample. The measurements are part of an ongoing programme to measure the spectral energy distributions of flat spectrum radio sources and to correlate them with the milliarcsecond structures from VLBI and other measured astrophysical properties. The 30-GHz data were obtained with a twin-beam differencing radiometer system mounted on the Torun 32-m telescope. The system has an angular resolution of 1.2 arcmin. Together with radio spectral data obtained from the literature, the 30-GHz data have enabled us to identify 42 of the CJF sources as Giga-hertz Peaked Spectrum (GPS) sources. Seventeen percent of the sources have rising spectra (alpha > 0) between 5 and 30 GHz.