First results with the ORPHEUS dark matter detector

The ORPHEUS dark matter detector is operating at our underground laboratory in Bern (70 m.w.e.). The detector relies on measuring the magnetic flux variation produced by weakly interacting massive particles (WIMPs) as they heat micron-sized superheated superconducting tin granules (SSG) and induce superconducting-to-normal phase transitions. In an initial phase, 0.45 kg of tin granules in a segmented detector volume have been used. In this paper a general description of the experimental set-up, overall performance of the detector, and first results are presented.Comment: 20 pages, Latex, submitted to Astropart. Phy

The Sunyaev-Zel'dovich effects from a cosmological hydrodynamical simulation: large-scale properties and correlation with the soft X-ray signal

Using the results of a cosmological hydrodynamical simulation of the concordance LambdaCDM model, we study the global properties of the Sunyaev-Zel'dovich (SZ) effects, both considering the thermal (tSZ) and the kinetic (kSZ) component. The simulation follows gravitation and gas dynamics and includes also several physical processes that affect the baryonic component, like a simple reionization scenario, radiative cooling, star formation and supernova feedback. Starting from the outputs of the simulation we create mock maps of the SZ signals due to the large structures of the Universe integrated in the range 0 < z < 6. We predict that the Compton y-parameter has an average value of (1.19 +/- 0.32) 10^-6 and is lognormally distributed in the sky; half of the whole signal comes from z < 1 and about 10 per cent from z > 2. The Doppler b-parameter shows approximately a normal distribution with vanishing mean value and a standard deviation of 1.6 10^-6, with a significant contribution from high-redshift (z > 3) gas. We find that the tSZ effect is expected to dominate the primary CMB anisotropies for l >~ 3000 in the Rayleigh-Jeans limit, while interestingly the kSZ effect dominates at all frequencies at very high multipoles (l >~ 7 10^4). We also analyse the cross-correlation between the two SZ effects and the soft (0.5-2 keV) X-ray emission from the intergalactic medium and we obtain a strong correlation between the three signals, especially between X-ray emission and tSZ effect (r_l ~ 0.8-0.9) at all angular scales.Comment: 12 pages, 15 figures. Accepted for publication in MNRAS. Minor changes, added reference

Euclid space mission: a cosmological challenge for the next 15 years

Euclid is the next ESA mission devoted to cosmology. It aims at observing most of the extragalactic sky, studying both gravitational lensing and clustering over $\sim$15,000 square degrees. The mission is expected to be launched in year 2020 and to last six years. The sheer amount of data of different kinds, the variety of (un)known systematic effects and the complexity of measures require efforts both in sophisticated simulations and techniques of data analysis. We review the mission main characteristics, some aspects of the the survey and highlight some of the areas of interest to this meetingComment: to appear in Proceedings IAU Symposium No. 306, 2014, "Statistical Challenges in 21st Century Cosmology", A.F. Heavens, J.-L. Starck & A. Krone-Martins, ed

Blood Flow and Glucose Metabolism in Stage IV Breast Cancer: Heterogeneity of Response During Chemotherapy

Objective: The purpose of the study was to compare early changes in blood flow (BF) and glucose metabolism (MRglu) in metastatic breast cancer lesions of patients treated with chemotherapy. Methods: Eleven women with stage IV cancer and lesions in breast, lymph nodes, liver, and bone were scanned before treatment and after the first course of chemotherapy. BF, distribution volume of water (Vd), MRglu/BF ratio, MRgluand its corresponding rate constants K1and k3were compared per tumor lesion before and during therapy. Results: At baseline, mean BF and MRgluvaried among different tumor lesions, but mean Vdwas comparable in all lesions. After one course of chemotherapy, mean MRgludecreased in all lesions. Mean BF decreased in breast and node lesions and increased in bone lesions. Vddecreased in breast and nodes, but did not change in bone lesions. The MRglu/BF ratio decreased in breast and bone lesions and increased in node lesions. In patients with multiple tumor lesions BF and MRgluresponse could be very heterogeneous, even within similar types of metastases. BF and MRgluincreased in lesions of patients who experienced early disease progression or showed no response during clinical follow-up. Conclusion: BF and MRgluchanges separately give unique information on different aspects of tumor response to chemotherapy. Changes in BF and MRgluparameters can be remarkably heterogeneous in patients with multiple lesions

Feedback and the Formation of Dwarf Galaxy Stellar Halos

Stellar population studies show that low mass galaxies in all environments exhibit stellar halos that are older and more spherically distributed than the main body of the galaxy. In some cases, there is a significant intermediate age component that extends beyond the young disk. We examine a suite of Smoothed Particle Hydrodynamic (SPH) simulations and find that elevated early star formation activity combined with supernova feedback can produce an extended stellar distribution that resembles these halos for model galaxies ranging from $v_{200}$ = 15 km s$^{-1}$ to 35 km s$^{-1}$, without the need for accretion of subhalos.Comment: 15 pages, 15 figures, accepted MNRA

Planck intermediate results. III. The relation between galaxy cluster mass and Sunyaev-Zeldovich signal

We examine the relation between the galaxy cluster mass M and Sunyaev-Zeldovich (SZ) effect signal D_A^2 Y for a sample of 19 objects for which weak lensing (WL) mass measurements obtained from Subaru Telescope data are available in the literature. Hydrostatic X-ray masses are derived from XMM-Newton archive data and the SZ effect signal is measured from Planck all-sky survey data. We find an M_WL-D_A^2 Y relation that is consistent in slope and normalisation with previous determinations using weak lensing masses; however, there is a normalisation offset with respect to previous measures based on hydrostatic X-ray mass-proxy relations. We verify that our SZ effect measurements are in excellent agreement with previous determinations from Planck data. For the present sample, the hydrostatic X-ray masses at R_500 are on average ~ 20 per cent larger than the corresponding weak lensing masses, at odds with expectations. We show that the mass discrepancy is driven by a difference in mass concentration as measured by the two methods, and, for the present sample, the mass discrepancy and difference in mass concentration is especially large for disturbed systems. The mass discrepancy is also linked to the offset in centres used by the X-ray and weak lensing analyses, which again is most important in disturbed systems. We outline several approaches that are needed to help achieve convergence in cluster mass measurement with X-ray and weak lensing observations.Comment: 19 pages, 9 figures, matches accepted versio