Properties of gas and dark matter in X-ray galaxy clusters with Sunyaev Zel'dovich measurements
Morandi, Andrea <1979>
Subject
FIS/05 Astronomia e astrofisica
Description
I have studied entropy profiles obtained in a sample of 24 X-ray objects at high
redshift retrieved from the Chandra archive. I have discussed the scaling
properties of the entropy S, the correlation between metallicity Z and S, the
profiles of the temperature of the gas, Tgas, and performed a comparison between the
dark matter 'temperature' and Tgas in order to constrain the non-gravitational
processes which affect the thermal history of the gas. Furthermore I have studied
the scaling relations between the X-ray quantities and Sunyaev Zel'dovich
measurements. I have observed that X-ray laws are steeper than the relations
predicted from the adiabatic model. These deviations from expectations based on
self-similarity are usually interpreted in terms of feedback processes leading to
non-gravitational gas heating, and suggesting a scenario in which the ICM at higher
redshift has lower both X-ray luminosity and pressure in the central regions than
the expectations from self-similar model. I have also investigated a Bayesian X-ray
and Sunyaev Zel'dovich analysis, which allows to study the external regions of the
clusters well beyond the volumes resolved with X-ray observations (1/3-1/2 of the
virial radius), to measure the deprojected physical cluster properties, like
temperature, density, entropy, gas mass and total mass up to the virial radius.
Morandi, Andrea (2008) Properties of gas and dark matter in X-ray galaxy clusters with Sunyaev Zel'dovich measurements, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Astronomia , 20 Ciclo. DOI 10.6092/unibo/amsdottorato/633.