We present a study of the stellar populations of galaxies in the cluster RX J0152.7À1357 at a redshift of 0.83. The study is based on new high signal-to-noise ratio spectroscopy of 29 cluster members covering the wavelength range 5000-10000 8, as well as r 0 i 0 z 0 photometry of the cluster. We use scaling relations between the central velocity dispersions of the galaxies and their luminosities, Balmer line strengths, and various metal line strengths to parameterize the differences between the members of RX J0152.7À1357 and our low-redshift comparison sample. The luminosities of the RX J0152.7À1357 galaxies and the strengths of the higher order Balmer lines H and H (for non-emission-line galaxies) appear to be in agreement with pure passive evolution of the stellar populations with a formation redshift z form % 4. However, the strengths of the D4000 indices and the metal indices do not support this interpretation. Compared with our low-redshift comparison sample, the metal indices (C4668, Fe4383, CN3883, G4300, and CN 2 ) show that at least half of the non-emission-line galaxies in RX J0152.7À1357 have an -element abundance ratio =Fe ½ of 0.2 dex higher, and about half of the galaxies have significantly lower metal content. X-ray data have previously shown that RX J0152.7À1357 is in the process of merging from two subclumps. We find that differences in stellar populations of the galaxies are associated with the location of the galaxies relative to the X-ray emission. The galaxies with weak C4668 and G4300, as well as galaxies for which weak [O ii] emission indicates a very recent star formation episode involving about 1% of the mass, are located in areas of low X-ray luminosity, on the outskirts of the two subclumps. It is possible that these galaxies are experiencing the effect of the cluster merger as (short) episodes of star formation, while the galaxies in the cores of the subclumps are unaffected by the merger. The spectroscopy of the RX J0152.7À1357 galaxies shows for the first time galaxies in a rich cluster at intermediate redshift that cannot evolve passively into the present-day galaxy population in rich clusters. Additional physical processes may be at work, and we speculate that merging with infalling (disk) galaxies in which stars have formed over an extended period might produce the required reduction in =Fe ½ . However, the merging could not be accompanied by star formation involving a substantial mass fraction. We note that our conclusions, in part, rely on stellar population models for which the predictions of the indices in the rest-frame blue have not yet been tested extensively.

We present the fundamental plane (FP) for 38 early-type galaxies in the two rich galaxy clusters RX J0152.7Ϫ1357 ( ) and RX J1226.9ϩ3332 ( ), reaching a limiting magnitude of in z p 0.83 z p 0.89 M p Ϫ19.8B the rest frame of the clusters. While the zero-point offset of the FP for these high-redshift clusters relative to our low-redshift sample is consistent with passive evolution with a formation redshift of , the FP for z ≈ 3.2 form the high-redshift clusters is not only shifted as expected for a mass-independent but rotated relative to the z form low-redshift sample. Expressed as a relation between the galaxy masses and the mass-to-light ratios, the FP is significantly steeper for the high-redshift clusters than for our low-redshift sample. We interpret this as a mass dependency of the star formation history, as has been suggested by other recent studies. The low-mass galaxies ( ) have experienced star formation as recently as (1.5 Gyr prior to their look-back time), while 10.3 10 M z ≈ 1.35, galaxies with masses larger than had their last major star formation episode at .11.310 M z 1 4.5 , Subject headings: galaxies: clusters: individual (RX J0152.7Ϫ1357, RX J1226.9ϩ3332) -galaxies: evolution -galaxies: stellar contentThe fundamental plane (FP) for elliptical (E) and lenticular (S0) galaxies is a key scaling relation, which relates the effective radii, the mean surface brightnesses, and the velocity dispersions in a relation that is linear in logarithmic space (e.g., Dressler et al. 1987;Djorgovski & Davis 1987;Jørgensen et al. 1996. The FP can be interpreted as a relation between the galaxy masses and their mass-to-light ratios ( ). For low-redshift cluster galaxies, the FP has very M/L low internal scatter (e.g., JFK1996). It is therefore a powerful tool for studying the evolution of the as a function of M/L redshift (e.g., Jørgensen et al. 1999;Kelson et al. 2000;van de Ven et al. 2003;Gebhardt et al. 2003;Wuyts et al. 2004;Treu et al. 2005;Ziegler et al. 2005). These authors all find that the FP at is consistent with the passive evoz p 0.2-1.0 lution of the stellar populations of the galaxies, generally with a formation redshift . Most previous studies of the FP z 1 2 form at cover fairly small samples of galaxies in each z p 0.2-1.0 cluster and are limited to a narrow range in luminosities, and therefore masses, making it very difficult to detect possible differences in the FP slope. A few recent studies indicated a steepening of the FP slope for galaxies (di Serego Ali- little for the two choices of profiles. In the following we use the parameters from -fits for consistency with our low-red-1/4 r shift comparison data. None of the main conclusions of this Letter would change had we chosen to use the Sérsic fits. Masses of the galaxies are derived as .Our Coma Cluster sample serves as the low-redshift reference sample (Jørgensen 1999). We have obtained new B-band photometry of this sample with the McDonald Observatory 0.8 m telescope and the Primary Focus Camera (Claver 1995). The data were r...

We present the results of a search for galaxy clusters in Subaru-XMM Deep Field. We reach a depth for a total cluster flux in the 0.5-2 keV band of 2x10^{-15} ergs cm^{-2} s^{-1} over one of the widest XMM-Newton contiguous raster surveys, covering an area of 1.3 square degrees. Cluster candidates are identified through a wavelet detection of extended X-ray emission. The red sequence technique allows us to identify 57 cluster candidates. We report on the progress with the cluster spectroscopic follow-up and derive their properties based on the X-ray luminosity and cluster scaling relations. In addition, 3 sources are identified as X-ray counterparts of radio lobes, and in 3 further sources, X-ray counterpart of radio lobes provides a significant fraction of the total flux of the source. In the area covered by NIR data, our identification success rate achieves 86%. We detect a number of radio galaxies within our groups and for a luminosity-limited sample of radio galaxies we compute halo occupation statistics using a marked cluster mass function. We compare the cluster detection statistics in the SXDF with the predictions of concordance cosmology and current knowledge of the X-ray cluster properties, concluding that a reduction of concordance sigma_8 value by 5% is required in order to match the prediction of the model and the data. This conclusion still needs verification through the completion of cluster follow-up.Comment: 15 pages, MNRAS sub

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CPAP produces a more rapid clinical and symptomatic improvement in patients with acute pulmonary oedema, particularly within the first hour. CPAP is a useful adjunctive treatment in the early management of acute heart failure.