Abstract Details
| Name: Abhirup Datta Affiliation: Indian Institute of Techonology Indore Conference ID: ASI2017_1311 Title : Understanding Merger Activities in Galaxy Clusters Using High Fidelity X-ray Temperature Maps and Radio Observations Authors and Co-Authors : Prof. Jack Burns Dr. Eric Hallman Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary Sciences, University of Colorado Boulder, Boulder, CO-80309, USA Abstract Type : Oral Abstract Category : Extragalactic astronomy Abstract : In the hierarchical structure formation framework, clusters of galaxies are the largest virialized objects in the universe and are ideal laboratories to study astrophysical plasma processes. Clusters are assembled through large and small merger activities which are among the most energetic events in the universe. During mergers cosmological shocks are driven into the intracluster medium (ICM). These shocks heat the ICM which is then detected in the soft X-ray regime through its thermal emission. In addition, these shocks accelerate non-thermal electrons and protons to relativistic speeds. The relativistic electrons have relatively short lifetimes (108 years) and emit synchrotron radiation which is then detected at the radio wavelengths. Steep spectrum radio relics and halos are now recognized as clear signposts of recent mergers. Direct evidence for cluster mergers has also been found from the disturbed X-ray surface brightness of the ICM. X-ray temperatures are very sensitive probes of recent merger or accretion events from the large-scale cosmic web. The understanding of the cluster mergers can be enhanced by combining the X-ray (high fidelity temperature maps) and radio (spectral index maps) observations. In this talk, we present our recent work on two galaxy clusters: Abell 3667 (non cool-core cluster with a cold front and hosting a double radio-relic) and Abell 85 (cool-core cluster hosting a single radio-relic). The high-fidelity X-ray temperature maps allowed us to study the X-ray shocks in the cluster using a new two-dimensional shock-finding algorithm. We will also present some new results from Abell 2744. High fidelity X-ray observations along with high dynamic range spectral index maps from upcoming telescopes like SKA (Square Kilometer Array) hold key to understand the shocks in galaxy cluster mergers. |