Year: 2002
Type: article
Abstract: We analyzed the luminosity-temperature ( L - T ) relation for two samples of galaxy clusters that have been observed by the ASCA satellite. We used 32 high-redshift clusters (0.3 < z < 0.6), 53 low-redshift clusters ( z < 0.3), and also the combination of the low- and high-redshift data sets. This is one of two surveys to use only ASCA data and has the largest number of high-redshift clusters. We assumed a power-law relation between the bolometric luminosity of the galaxy cluster and its integrated temperature (uncorrected for cooling flows) and redshift [ L bol, 44 = CT α (1 + z ) A ]. We found that for an Ω M = 1.0, Ω Λ = 0.0 universe, A = 1.134 ± 1.66, α = 2.815 ± 0.42, and log C = -1.167 ± 0.25, and for an Ω M = 0.3, Ω Λ = 0.7 universe, A = 2.052 ± 1.63, α = 2.822 ± 0.43, and log C = -1.126 ± 0.26 (all errors at 68% confidence for one and two interesting parameters). We found the dispersion at constant kT in this relation to be Δ log L = 0.282 for Ω M = 1.0, Ω Λ = 0.0, and Δ log L = 0.283 for Ω M = 0.3, Ω Λ = 0.7. The results for the combined data set and those found using the low- and high-redshift clusters are consistent and independent of cosmology, with previous estimates of L ∼ T 3 found by other authors. The observed weak or zero evolution agrees with the predictions of models that produce L ∼ T 3 incorporating an initial source of nongravitational energy before cluster collapse.
Source: The Astronomical Journal
DOI: 10.1086/344162
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2070356459