Tata Institute of Fundamental Research
National Centre for Radio Astrophysics
We present multifrequency observations with the Giant Metrewave Radio Telescope (GMRT) and the Very Large Array (VLA) of a sample of seventeen largely giant radio sources (GRSs). These observations have either helped clarify the radio... more
We present new radio observations at frequencies ranging from 240 to 4860 MHz of the well-known, double-double radio galaxy (DDRG), J1453+3308, using both the Giant Metrewave Radio Telescope (GMRT) and the Very Large Array (VLA). These... more
We present radio continuum observations with the VLA at 3.6 and 6 cm and with MERLIN at 18 cm of a sample of mildly active galaxies, including the archetypal starburst galaxies NGC 1808 and 253, both of which have a large number of... more
Giant radio sources (GRSs), defined to be those with a projected linear size greater than approximately 1 Mpc, are the largest single objects in the Universe, and are useful for probing a number of astrophysical questions. In this paper... more
We present multi-wavelength radio observations with the Very Large Array and narrow- and broad-band optical observations with the 2.5m telescope at the Las Campanas Observatory, of a well-defined sample of high-luminosity Fanaroff-Riley... more
As Compact Steep Spectrum radio sources have been shown to be more asymmetrical than larger sources of similar powers, there is a high probability that they interact with an asymmetric medium in the central regions of the host elliptical... more
We study the collimation of radio jets in the high-luminosity Fanaroff-Riley class II sources by examining the dependence of the sizes of hotspots and knots in the radio jets on the overall size of the objects for a sample of compact... more
We present total-intensity and linear-polarization observations made with the Very Large Array at $\lambda$20 and 6 cm of a representative sample of 42 radio galaxies and quasars selected from the Molonglo Complete Sample. The sources... more
The compact steep spectrum and gigahertz peaked spectrum sources are widely believed to be young radio sources, with ages <10^6 yr. If the activity in the nucleus is fuelled by the supply of gas, one might find evidence of this gas by... more
We present the results of 5-GHz observations with the VLA A-array of a sample of candidate Compact Steep Spectrum sources (CSSs) selected from the S4 survey. We also estimate the symmetry parameters of high-luminosity CSSs selected from... more
The role of radio polarimetry in the understanding of GPS and CSS sources is explored. After an initial discussion of what can be learned from polarimetry, the expectations of a simple evolutionary sequence of GPS/CSO to CSS to FR i/FR ii... more
Two Compact Steep-spectrum Sources (CSSs), 0548+165 and 1524−136, chosen from a list of CSSs with polarization percentages that decrease with decreasing frequency and high rotation measure values (RM > 450 rad m −2) on arcsecond scales,... more
We present radio observations of 19 candidate compact steep-spectrum (CSS) objects selected from a well-defined, complete sample of 52 B2 radio sources of intermediate strength. These observations were made with the VLA A-array at 4.835... more
We present radio observations at frequencies ranging from 240 to 8460 MHz of the radio galaxy 4C 29.30 (J0840+2949) using the Giant Metrewave Radio Telescope (GMRT), the Very Large Array (VLA) and the Effelsberg telescope. We report the... more
We present low-frequency, GMRT (Giant Metrewave Radio Telescope) observations at 333 and 617 MHz of the most-distant giant quasar, J1432+158, which is at a redshift of 1.005. The radio source has a total angular extent of 168 arcsec,... more
We report on the detection of a z abs = 0.3654 associated absorption-line system in the ultraviolet spectrum of the compact steep-spectrum source (CSS) quasar 3C 48. The absorbing material is blueshifted with respect to the quasar... more
We present low-frequency observations starting from ∼150 MHz with the Giant Metrewave Radio Telescope (GMRT), and high-frequency observations with the Very Large Array (VLA) of two large radio galaxies 3C46 and 3C452. These observations... more
Multifrequency observations with the Giant Metrewave Radio Telescope (GMRT) and the Very Large Array (VLA) are used to determine the spectral breaks in consecutive strips along the lobes of a sample of selected giant radio sources (GRSs)... more