Scaling relations for galaxy clusters: properties and evolution

Well-calibrated scaling relations between the observable properties and the total masses of clusters of galaxies are important for understanding the physical processes that give rise to these relations. They are also a critical ingredient for studies that aim to constrain cosmological parameters using galaxy clusters. For this reason much effort has been spent during the last decade to better understand and interpret relations of the properties of the intra-cluster medium. Improved X-ray data have expanded the mass range down to galaxy groups, whereas SZ surveys have openened a new observational window on the intracluster medium. In addition,continued progress in the performance of cosmological simulations has allowed a better understanding of the physical processes and selection effects affecting the observed scaling relations. Here we review the recent literature on various scaling relations, focussing on the latest observational measurements and the progress in our understanding of the deviations from self similarity.Comment: 38 pages. Review paper. Accepted for publication in Space Science Reviews (eds: S. Ettori, M. Meneghetti). This is a product of the work done by an international team at the International Space Science Institute (ISSI) in Bern on "Astrophysics and Cosmology with Galaxy Clusters: the X-ray and Lensing View

Intrinsic galaxy shapes and alignments II: Modelling the intrinsic alignment contamination of weak lensing surveys

Intrinsic galaxy alignments constitute the major astrophysical systematic of forthcoming weak gravitational lensing surveys but also yield unique insights into galaxy formation and evolution. We build analytic models for the distribution of galaxy shapes based on halo properties extracted from the Millennium Simulation, differentiating between early- and late-type galaxies as well as central galaxies and satellites. The resulting ellipticity correlations are investigated for their physical properties and compared to a suite of current observations. The best-faring model is then used to predict the intrinsic alignment contamination of planned weak lensing surveys. We find that late-type galaxy models generally have weak intrinsic ellipticity correlations, marginally increasing towards smaller galaxy separation and higher redshift. The signal for early-type models at fixed halo mass strongly increases by three orders of magnitude over two decades in galaxy separation, and by one order of magnitude from z=0 to z=2. The intrinsic alignment strength also depends strongly on halo mass, but not on galaxy luminosity at fixed mass, or galaxy number density in the environment. We identify models that are in good agreement with all observational data, except that all models over-predict alignments of faint early-type galaxies. The best model yields an intrinsic alignment contamination of a Euclid-like survey between 0.5-10% at z>0.6 and on angular scales larger than a few arcminutes. Cutting 20% of red foreground galaxies using observer-frame colours can suppress this contamination by up to a factor of two.Comment: 23 pages, 14 figures; minor changes to match version published in MNRA

Quality of Life After Axillary or Groin Sentinel Lymph Node Biopsy, With or Without Completion Lymph Node Dissection, in Patients With Cutaneous Melanoma

The aim of this study was to asses quality of life (QoL) after axillary or inguinal sentinel lymph node biopsy (SLNB) with or without completion lymph node dissection (CLND) in patients with cutaneous melanoma by comparing patients to a norm group of the general population and by comparing QoL between four patient groups depending on surgical procedure and location, i.e., patients receiving an axillary or groin SLNB, or an axillary or groin CLND.Between 1995 and 2003, a total of 242 axillary and inguinal SLNBs were performed. Of the 127 patients eligible for the study, 116 patients participated (91%). QoL was measured by the 30-item European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), the McGill Pain Questionnaire and the Groningen Activity Restriction Scale.Median age at diagnosis was 50 (range, 18-77) years; median Breslow thickness 2.0 (range, 1-13) mm; median follow-up 56 (range, 4-94) months. SLNB only was performed in 89 patients (77%): 48 in the groin and 41 in the axilla. CLND was performed in 27 patients (23%): 13 in the axilla and 14 in the groin. More postoperative complications (13 vs. 5; P &lt;0.001) and lymphedema (10 vs. 8; P &lt;0.001) occurred in the CLND group than in the SLNB group. The total group of patients reported better physical (P &lt;0.001), role (P &lt;0.001), emotional (P &lt;0.001), and social functioning (P = 0.049), global QoL (P &lt;0.001), and less fatigue (P &lt;0.001) and pain (P &lt;0.001) than a German norm group. Analysis of variance revealed significant differences in role functioning (P = 0.02) and tendencies toward physical problems (P = 0.051) and fatigue (P = 0.051) between the four groups. Post hoc Bonferroni tests showed that the axillary CLND group had more problems than the axillary and inguinal SLNB groups. Kruskal-Wallis tests showed that the axillary CLND group reported most pain.QoL in melanoma survivors after axillary or inguinal SLNB with or without CLND was better than that in a norm group. Patients who underwent CLND in the axilla after SLNB reported most problems.</p