| Abstract : | Galaxy clusters are the massive (as high as ~10^15 M_sun) gravitationally bound objects in the Universe. Many massive clusters (> 5x10^14 M_sun) have been studied in radio bands which have provided ample evidence for the presence of relativistic electrons and magnetic fields (non-thermal components) in their intra-cluster medium. However, poor clusters (<5x10^14 M_sun) have not been studied much in radio bands and the status of the non-thermal content in such systems remains largely unknown. The limitations in the sensitivity of telescopes at low radio frequencies and the absence of a theoretical estimate for favourable detection of diffuse radio emission from these objects have so far discouraged their systematic studies. Fortunately, the commissioning of the uGMRT and the LoFAR telescopes with unprecedented sensitivity in recent times have opened up the possibilities of their detection. In this changed scenario, we thus aim to search for the diffuse radio emission from the systematically chosen poor clusters starting with the objects in the transitional mass range (10^14 ~ M < 5x10^14). For this survey project, we select a sample of 36 galaxy clusters from low-redshift (z~0.1) in this mass (M) range from the largest available Planck Sunyaev-Zeldovich cluster list, roughly in the GMRT exclusive declination range, adhering to the maximum possible mass completeness and are unbiased towards cluster mergers. In the first phase of this uGMRT Low MAss Cluster Survey (GLOMACS-I), we observed 13 low-mass clusters with the uGMRT at band 3. Interestingly, we detect diffuse radio emissions from most of them. In this talk, I will present all new interesting results from the first phase GLOMAC survey which includes spectacular discoveries of diffuse emission connected to cluster halo, many steep and ultra-steep spectrum sources, new radio relics and most intriguingly a relic in the core region of a cluster and many more. |
