Abstract Details
| Name: Sravani Vaddi Affiliation: NCRA-TIFR Conference ID: ASI2018_1211 Title : HST COS Spectroscopy of Cooling Flow Filaments in A2597 and Zw3146 Authors and Co-Authors : Grant Tremblay (Yale University, USA) Chris O'Dea (University of Manitoba, Department of Physics and Astronomy, Manitoba, Canada) Stefi Baum (University of Manitoba, Department of Physics and Astronomy, Manitoba, Canada) Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : Heating by AGN through outflows has gained fundamental importance in the study of large-scale structure and galaxy formation and is often invoked to quench the radiative cooling of the hot intracluster medium (ICM) onto the brightest cluster galaxy (BCG). However, in cool-core clusters where the ICM cooling rate is shorter than the age of the cluster, AGN heating does not completely offset radiative losses and significant additional ionization mechanism is necessary to explain the observed temperature and line ratios of the filamentary emission line nebulae around the cool core BCGs. In an effort to find the source of this mysterious ionization, we have obtained deep FUV spectroscopy using the HST cosmic origins spectrograph of the filaments of two cool-core galaxy clusters A2597 and ZW3146. Spectral diagnostics in the FUV are capable of discriminating between various heating models (stellar photoionization, thermal conduction, cosmic ray heating and shock heating). Using photoionization codes MAPPINGS and CLOUDY, different ionizing sources have been simulated and consists of single and hybrid models. We notice that shock heating is more efficient than individual models of AGN/stellar photoionization/Bremmstrahlung or hybrid AGN-Stellar photoionization model in explaining the high ionization state of the BCG. |