Abstract Details
| Name: Surajit Paul Affiliation: SP Pune University Conference ID: ASI2019_464 Title : `Bullet' cluster event and its observed properties: A reality check in $\Lambda CDM$ model using cosmological simulations Authors and Co-Authors : Surajit Paul*, Prateek Gupta, Reju Sam John and Shubham Bhagat Abstract Type : Poster Abstract Category : Extragalactic Astronomy Abstract : The cluster 1E 0657$-$55.8, also known as the `Bullet cluster', is an extreme and rare merging event in the universe. Unlike the usual situation where baryons remain trapped inside the dark matter halos, multi-wavelength observations of `Bullet' cluster show an offset of gravitational potential and X-ray peak, indicating a clear separation of baryons from the dark matter (DM), which, by some researchers, thought to be a challenge to the $\Lambda$CDM cosmology. In the last decade, several attempts were made to simulate such systems to understand the underlying physics of this extreme event, but, mostly with artificial mergers. Here, we present a maiden attempt of numerical modelling of a 3D, realistic `Bullet' like event and possible observables (i.e. X-ray and radio emissions) in a full cosmological ($\Lambda$CDM) environment with dark matter plus baryons. We report a simulated `Bullet', a fine replica of the observed one with reproduction of reported extremities such as speed of 2700 km s$^{-1}$, supersonic bow shock of Mach $M>3$ and a clear evidence of temporal separation of dark matter and baryons found just within a (128 $Mpc\;h^{-1}$)$^3$ co-moving volume, assuring no challenge to $\Lambda$CDM cosmology from the `Bullet' event as of now. Further, we present a time evolution study of thermal (X-ray) and computed radio properties (non-thermal) of our simulated `Bullet' event to match the observational morphologies as well as to understand the full event, formed inside a filamentary cosmic structure using animated visualisation. |