Properties of gas and dark matter in X-ray galaxy clusters with Sunyaev Zel'dovich measurements

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.

Grantor dc:publisher

Alma Mater Studiorum - Università di Bologna

Year dc:date

2008

Author dc:creator

• Morandi, Andrea <1979>

Contributors dc:contributor

• Moscardini, Lauro

• FIS/05 Astronomia e astrofisica

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

en

Identifier

urn:nbn:it:unibo-604

OAI identifier oai:identifier

oai:amsdottorato.cib.unibo.it:633