The ROSAT-ESO Flux Limited X-ray Galaxy Cluster Survey (REFLEX II) I. Newly identified X-ray luminous clusters at z>=0.2

We report 19 intermediate redshift clusters newly detected in the ROSAT All-Sky survey that are spectroscopically confirmed. They form a part of 911 objects in the REFLEX II cluster catalogue with a limiting flux of 1.8\times10^12 erg/s/cm2 in the 0.1-2.4 keV ROSAT band at redshift z >= 0.2. In addition we report three clusters from the REFLEX III supplementary catalogue, which contains objects below the REFLEX II flux limit but satisfies the redshift constraint above. These clusters are spectroscopically followed-up by our ESO NTT-EFOSC2 campaigns for the redshift measurement. We describe our observing and data reduction methods. We show how X-ray properties such as spectral hardness ratio and source extent can be used as important diagnostics in selecting galaxy cluster candidates. Physical properties of the clusters are subsequently calculated from the X-ray observations. This sample contains the high mass and intermediate-redshift galaxy clusters for astrophysical and cosmological applications.Comment: Astronomy and Astrophysics (in press

Machiavellianism, relationship satisfaction, and romantic relationship quality

Machiavellianism is characterised by a manipulative interpersonal style, willingness to exploit others, and a preference for emotionally detached relationships. The present studies investigate the extent to which Machiavellianism influences relationship satisfaction and romantic relationship quality. In study 1, 194 heterosexual partnered women completed Machiavellianism and Relationship Satisfaction measures. Women with higher levels of Machiavellianism reported lower levels of relationship satisfaction. In study 2, 132 heterosexual partnered women completed Machiavellianism, Trust, Commitment, Control, and Emotional Abuse scales. Women with higher levels of Machiavellianism perceived their partners to be less dependable, reported less faith in their partners, and were less willing to persist with the relationship than those with low levels of Machiavellianism. With regards to negative behavior, Machiavellianism predicted each form of control and emotional abuse investigated, such that those with high levels of Machiavellianism were more likely to engage in controlling behaviors and emotional abuse. Findings have important implications for the prediction of romantic relationship quality and in particular for negative behavior such as control and abuse

Machiavellianism and schadenfreude in women's friendships

The present study investigated the relationship between Machiavellianism, envy, competition, and schadenfreude in women's same-sex friendships. Women (N = 133) completed an online questionnaire measuring Machiavellianism, envy, competition, and three author generated vignettes measuring expressed schadenfreude in relation to a same-sex friend. Women with higher levels of Machiavellianism expressed greater feelings of pleasure in response to their same-sex friend's misfortunes in a romantic relationship and their physical appearance but not in relation to academic abilities. Envy predicted feelings of schadenfreude in academic and romantic relationships whilst competition predicted feelings of schadenfreude in all three scenarios. Future research should explore how characteristics of the target and different forms of envy may influence responses to a friend's misfortune in individuals with higher levels of Machiavellianism

The Power Spectrum of Flux Limited X-Ray Galaxy Cluster Surveys

We compute the redshift space power spectrum of two X-ray cluster samples: the X-ray Brightest Abell Cluster Sample (XBACS) and the Brightest Cluster Sample (BCS) using the method developed by Feldman, Kaiser & Peacock. The power spectrums derived for these samples are in agreement with determinations of other optical and X-ray cluster samples. For XBACS we find the largest power spectrum amplitude expected given the high richness of this sample ($R \ge 2$). In the range 0.05 \uk < k < 0.4 \uk the power spectrum shows a power law behavior $P(k)\propto k^{n}$ with an index $n\simeq-1.2$. In a similar range 0.04 \uk < k < 0.3 \uk BCS power spectrum has a smaller amplitude with index $n\simeq-1.0$. We do not find significant evidence for a peak at k \simeq 0.05 \uk suggesting that claims such of feature detections in some cluster samples could relay on artificial inhomogeneities of the data. We compare our results with power spectrum predictions derived by Moscardini et al. within current cosmological models (LCDM and OCDM). For XBACS we find that both models underestimate the amplitude of the power spectrum but for BCS there is reasonably good agreement at k\gsim 0.03 \uk for both models.Comment: 9 pages (LateX, mn.sty), 9 figures, accepted for publication in MNRA

Missing baryons and the soft X-ray background

The X-ray background intensity around Lick count galaxies and rich clusters of galaxies is investigated in three ROSAT energy bands. It is found that the X-ray enhancements surrounding concentrations of galaxies exhibit significantly softer spectrum than the standard cluster emission and the average extragalactic background. The diffuse soft emission accompanying the galaxies is consistent with the thermal emission of the hot gas postulated first by the Cen & Ostriker hydrodynamic simulations. Our estimates of the gas temperature - although subject to large uncertainties - averaged over several Mpc scales are below 1 keV, which is substantially below the temperature of the intra-cluster gas, but consistent with temperatures predicted for the local intergalactic medium. It is pointed out that the planned ROSITA mission would be essential for our understanding of the diffuse thermal component of the background.Comment: AA accepted, 6 pages, incl. 4 figure

Small-sample corrections for score tests in Birnbaum-Saunders regressions

In this paper we deal with the issue of performing accurate small-sample inference in the Birnbaum-Saunders regression model, which can be useful for modeling lifetime or reliability data. We derive a Bartlett-type correction for the score test and numerically compare the corrected test with the usual score test, the likelihood ratio test and its Bartlett-corrected version. Our simulation results suggest that the corrected test we propose is more reliable than the other tests.Comment: To appear in the Communications in Statistics - Theory and Methods, http://www.informaworld.com/smpp/title~content=t71359723

Luminous superclusters: remnants from inflation

We derive the luminosity and multiplicity functions of superclusters compiled for the 2dF Galaxy Redshift Survey, the Sloan Digital Sky Survey (Data Release 4), and for three samples of simulated superclusters. We find for all supercluster samples Density Field (DF) clusters, which represent high-density peaks of the class of Abell clusters, and use median luminosities/masses of richness class 1 DF-clusters to calculate relative luminosity/mass functions. We show that the fraction of very luminous (massive) superclusters in real samples is more than tenfolds greater than in simulated samples. Superclusters are generated by large-scale density perturbations which evolve very slowly. The absence of very luminous superclusters in simulations can be explained either by non-proper treatment of large-scale perturbations, or by some yet unknown processes in the very early Universe.Comment: 6 pages, 3 Figures, submitted for Astronomy and Astrophysic