Conclusion

In this thesis work, we have used our observations to define good calibrators for GMRT at 610 MHz and 235 MHz. Out of the 150 observed sources we could identify $\sim$ 102 sources as good calibrators at 610 MHz based on the criteria established. Although we could not find more number of calibrators at 235 MHz, we can still use quite a few number of the sources as calibrators at that frequency, since the distribution of the flux density over the baselines of the GMRT for 235 MHz is now known. In Appendix A & B we have summarized the detailed information on each source which has been observed for this project.

This project was the first attempt for identifying calibrators for GMRT at low radio frequencies. The procedure which has been established for data reduction can be used for data analysis of more such observations.

From the observations of the sources at low radio frequencies and the spectra of the sources, we could study their behaviour and structure at these frequencies.