Abstract Details
| Name: Avni Paresh Parmar Affiliation: Pune University Conference ID: ASI2017_1307 Title : Exploring diffuse radio sources in low massive clusters and groups Authors and Co-Authors : Prof. Dwarakanath, Viral Parekh (Postdoc fellow) Raman Research Institute Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : Radio interferometry observations have shown the existence of diffuse large scale emission from the intracluster medium (ICM), suggesting that non-thermal components, magnetic fields and relativistic particles, are mixed with the hot ICM. One class of these diffuse radio sources is known as radio halos which are detected in a fraction of galaxy clusters. Formation of radio halo is still open debate. They are useful to probe relativistic particles, magnetic field, and whole cluster formation and evolution. In this presentation we will talk about the our ongoing project of systematic search of diffuse radio sources within the GLEAM (GaLactic and Extragalactic All-sky MWA survey) survey. GLEAM is a survey of the entire radio sky south of declination +25 deg at frequencies between 72 and 231 MHz, made with the MWA (Murchison Widefield Array), the low-frequency Square Kilometre Array (SKA1 LOW) precursor located in Western Australia. We used wide-band images (170-231 MHz, central frequency 200 MHz) which have rms of ~ 7mJy/beam and resolution of ~ 2'. In order to find the position of clusters into GLEAM data, we used a catalog of clusters of galaxies identified from Sloan Digital Sky Survey III (SDSS-III). There are total 132,684 clusters in redshift range 0.05≤z<0.8 with homogenised properties such as redshift, 0.1-2.4 keV band luminosity (L500), total mass (M500), etc. available for each cluster. In this work, we have visually inspected 784 wide-band radio images for nearby (z<0.1) clusters with different mass ranges to find diffuse radio sources such as relics, large halo or mini halo. Along with MWA data, we also utilised other radio survey data such as NVSS, SUMSS and TGSS. We also checked corresponding X-ray images to understand dynamical states of galaxy clusters. We have derived total of ~10 clusters which shows promising diffuse radio sources in MWA data. Currently, for some of these clusters we have obtained high resolution and sensitive GMRT low frequencies observations. We will show results of this analysis and discuss about occurrence of radio halos in nearby as well as distant clusters in frame work of low-frequency MWA observations.   |