We present new X-ray temperatures and improved X-ray luminosity estimates for 15 new and archival XMM-Newton observations of galaxy clusters at intermediate redshift with mass and luminosities near the galaxy group/cluster division ( \mathrm { M } _ { 2500 } < 2.4 \times 10 ^ { 14 } h _ { 70 } ^ { -1 } \mathrm { M } _ { \odot } , \mathrm { L } < 2 \times 10 ^ { 44 } \mathrm { erg } \mathrm { s } ^ { -1 } , 0.3 < \mathrm { z } < 0.6 ) .
These clusters have weak-lensing mass measurements based on Hubble Space Telescope observations of clusters representative of an X-ray selected sample ( the ROSAT 160SD survey ) .
The angular resolution of XMM-Newton allows us to disentangle the emission of these galaxy clusters from nearby point sources , which significantly contaminated previous X-ray luminosity estimates for six of the fifteen clusters .
We extend cluster scaling relations between X-ray luminosity , temperature , and weak-lensing mass for low-mass , X-ray-selected clusters out to redshift \sim 0.45 .
These relations are important for cosmology and the astrophysics of feedback in galaxy groups and clusters .
Our joint analysis with a sample of 50 clusters in a similar redshift range but with larger masses ( \mathrm { M } _ { 500 } < 21.9 \times 10 ^ { 14 } \mathrm { M } _ { \odot } , 0.15 \leq \mathrm { z } \leq 0.55 ) from the Canadian Cluster Comparison Project finds that within \mathrm { r } _ { 2500 } , \mathrm { M } \propto \mathrm { L } ^ { 0.44 \pm 0.05 } , \mathrm { T } \propto \mathrm { L } ^ { 0.23 \pm 0.02 } , and \mathrm { M } \propto \mathrm { T } ^ { 1.9 \pm 0.2 } .
The estimated intrinsic scatter in the M-L relation for the combined sample is reduced to \sigma _ { \log ( M|L ) } = 0.10 , from \sigma _ { \log ( M|L ) } = 0.26 with the original ROSAT measurements .
We also find an intrinsic scatter for the T-L relation , \sigma _ { \log ( T|L ) } = 0.07 \pm 0.01.