Speaker
Description
We present two new radio continuum images obtained with Apertif at 1.4 GHz. The images, produced with a direction-dependent
calibration pipeline, cover 136 square degrees of the Lockman Hole and 24 square degrees of the ELAIS-N fields, with an average
resolution of 17×12′′ and residual noise of 33 μJy/beam. With the improved depth of the images we found in total 63692 radio
sources, many of which are detected for the first time at this frequency. With the addition of the previously published Apertif catalog
for the Boötes field, we cross-match with the LOFAR deep-fields value-added catalogs at 150 MHz, resulting in a homogeneous
sample of 10196 common sources with spectral index estimates, one of the largest to date. We analyze and discuss the correlations
between spectral index, redshift, linear sources size, and radio luminosity, taking into account biases of flux-density-limited surveys.
Our results suggest that the observed correlation between spectral index and redshift of active galactic nuclei can be attributed to the
Malmquist bias reflecting an intrinsic relation between radio luminosity and the spectral index. We also find correlation between
spectral index and linear source size with more compact sources having steeper spectra.
| Talk category | NOVA Network 1 |
|---|---|
| Preference for a talk or poster | Talk |
