A multifrequency study of the large radio galaxies 3C46 and 3C452

Abstract

We present low-frequency observations starting from ∼150 MHz with the Giant Metrewave Radio Telescope, and high-frequency observations with the Very Large Array of two large radio galaxies 3C46 and 3C452. These observations were made with the objectives of estimating their spectral ages and examining any evidence of diffuse extended emission at low radio frequencies due to an earlier cycle of activity. While no evidence of extended emission due to an earlier cycle of activity has been found, the spectral ages have been estimated to be ∼15 and 27 Myr for the oldest relativistic plasma seen in the regions close to the cores for 3C46 and 3C452, respectively. The spectra in the vicinity of the hotspots are consistent with a straight spectrum with injection spectral indices of ∼1.0 and 0.78, respectively, somewhat steeper than theoretical expectations.