ترغب بنشر مسار تعليمي؟ اضغط هنا

73 - Iu. Babyk , I. Vavilova 2013
We analyzed the luminosity-temperature-mass of gas (L_{X} - T - M_{g}) relation for sample of galaxy clusters that have been observed by the Chandra satellite. We used 21 high-redshift clusters (0.4 < z < 1.4). We assumed a power-law relation betwe en the X-ray luminosity of galaxy clusters and its temperature and redshift L_{X} ~ (1+z)^{A_{L_{X}T}}T^{beta_{L_{X}T}}. We obtained that for an Omega_{m} = 0.27 and Lambda = 0.73 universe, A_{L_{X}T} = 1.50 +/- 0.23, beta_{L_{X}T} = 2.55 +/- 0.07 (for 68% confidence level). Then, we found the evolution of M_{g} - T relation is small. We assumed a power-law relation in the form M_{g} ~ (1+z)^{A_{M_{g}T}}T^{beta_{M_{g}T}} also, and we obtained A_{M_{g}T} = -0.58 +/- 0.13 and beta_{M_{g}T} = 1.77 +/- 0.16. We also obtained the evolution in M_{g} - L_{X} relation, we can conclude that such relation has strong evolution for our cosmological parameters. We used M_{g} ~ (1+z)^{A_{M_{g}L_{X}}}L^{beta_{M_{g}L_{X}}} equation for assuming this relation and we found A_{M_{g}L_{X}} ~ -1.86 +/- 0.34 and beta_{M_{g}L_{X}} = 0.73 +/- 0.15 for Omega_{m} = 0.27 and Lambda = 0.73 universe. In overal, the clusters on big redshifts have much stronger evolution between correlations of luminosity, temperature and mass, then such correlations for clusters at small redshifts. We can conclude that such strong evolution in L_{X} - T - M_{g} correlations indicate that in the past the clusters have bigger temperature and higher luminosity.
We present results based on Chandra observations of a large sample of 129 hot galaxy clusters. We measure the concentration parameter c_200, the dark mass M_200 and the baryonic mass content in all the objects of our sample, providing the largest dat aset of mass parameters for galaxy clusters in the redshift range z = 0.01 - 1.4. We confirm a that a tight correlation between c_200 and M_200, c propto M^a_vir /(1+z)^b with a = -0.56 +/- 0.15 and b =0.80 +/- 0.25 (68 per cent confidence limits), is present, in good agreement with the predictions from numerical simulations and previous observations. Fitting the mass profile with a generalized NFW model, we got the inner slope alpha, with alpha = 0.94 +/- 0.13. Finally, we show that the inner slope of the density profile, alpha correlates with the baryonic mass content, M_b : namely alpha is decreasing with increasing baryonic mass content.
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا