We present low-frequency observations with the Giant Metrewave Radio
Telescope (GMRT) of a sample of giant radio sources (GRSs), and high-frequency
observations of three of these sources with the Very Large Array (VLA). From
multifrequency observations of the lobes we estimate the magnetic field
strengths using three different approaches, and show that these differ at most
by a factor of ∼3. For these large radio sources the inverse-Compton
losses usually dominate over synchrotron losses when estimates of the classical
minimum energy magnetic field are used, consistent with earlier studies.
However, this is often not true if the magnetic fields are close to the values
estimated using the formalism of Beck & Krause. We also examine the spectral
indices of the cores and any evidence of recurrent activity in these sources.
We probe the environment using the symmetry parameters of these sources and
suggest that their environments are often asymmetric on scales of ∼1 Mpc,
consistent with earlier studies.Comment: 14 pages, 5 figures, 6 tables, one appendix; accepted for publication
in MNRA