Brilho superficial em raio-x de aglomerados de galáxias, opacidade cósmica e limites no parâmetro de densidade de matéria.

Abstract

X-ray surface brightness of galaxy clusters, cosmic opacity and limits on the matter density parameter. In recent years, many tests have been proposed to verify the existence of some cosmic opacity sources in astronomical observations. The idea has been to use observational data that depend on the hypothesis of cosmic transparency with others that are independent. This was the main focus this work. Was used two samples of gas mass fraction measurements of galaxy clusters obtained from their X-ray surface brightness, which are affected by a possible presence of opacity source, and recent data of the cosmic expansion rate, H(z), which are independent of a such presence. Was concluded that a transparent universe is allowed with a high degree of statistical confidence in the X-ray region of the electromagnetic spectrum, but more restrictive analyzes still need to be performed with future data. The results this work are in full agreement with previous studies which used other astronomical data, such as observations of type Ia supernovae and gamma ray bursts.