Mass profiles and concentration-dark matter relation in X-ray luminous galaxy clusters - Astrophysics > Cosmology and Nongalactic AstrophysicsReportar como inadecuado




Mass profiles and concentration-dark matter relation in X-ray luminous galaxy clusters - Astrophysics > Cosmology and Nongalactic Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: Abriged Assuming that the hydrostatic equilibrium holds between theintracluster medium and the gravitational potential, we constrain the NFWprofiles in a sample of 44 X-ray luminous galaxy clusters observed withXMM-Newton in the redshift range 0.1-0.3. We evaluate several systematicuncertainties that affect our reconstruction of the X-ray masses. We measurethe concentration c200, the dark mass M200 and the gas mass fraction withinR500 in all the objects of our sample, providing the largest dataset of massparameters for galaxy clusters in this redshift range. We confirm that a tightcorrelation between c200 and M200 is present and in good agreement with thepredictions from numerical simulations and previous observations. When weconsider a subsample of relaxed clusters that host a Low-Entropy-Core LEC, wemeasure a flatter c-M relation with a total scatter that is lower by 40 percent. From the distribution of the estimates of c200 and M200, with associatedstatistical 15-25% and systematic 5-15% errors, we use the predicted valuesfrom semi-analytic prescriptions calibrated through N-body numerical runs andmeasure sigma 8*Omega m^0.60+-0.03= 0.45+-0.01 at 2 sigma level, statisticalonly for the subsample of the clusters where the mass reconstruction has beenobtained more robustly, and sigma 8*Omega m^0.56+-0.04 = 0.39+-0.02 for thesubsample of the 11 more relaxed LEC objects. With the further constraint fromthe fgas distribution in our sample, we break the degeneracy in thesigma 8-Omega m plane and obtain the best-fit values sigma 8~1.0+-0.20.75+-0.18 when the subsample of the more relaxed objects is considered andOmega m = 0.26+-0.01.



Autor: S. Ettori, F. Gastaldello, A. Leccardi, S. Molendi, M. Rossetti, D. Buote, M. Meneghetti

Fuente: https://arxiv.org/







Documentos relacionados