Trouble for cluster parameter estimation from blind SZ surveys?

(Abriged version) The Sunyaev-Zel'dovich (SZ) effect of galaxy clusters is a tool to measure three quantities: Compton parameter, electron temperature, and cluster peculiar velocity. However, a major problem is non-removed contamination by astrophysical sources that emit in the SZ frequencies. This includes interstellar dust emission, infra-red (IR) galaxies, and radio sources in addition to primary Cosmic Microwave Background (CMB) anisotropies. The three former contaminations induce systematic shifts in the three SZ parameters. In this study, we carefully estimated, both for a large beam experiment (namely Planck Surveyor) and a small beam experiment (ACT-like), the systematic errors that result if a fraction of the expected levels of emission from dust, IR galaxies, and radio sources remains non-removed. ...Comment: Accepted version (09/03/2005) in press in A&A. Modified content and title, SPT section remove

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Galaxy Formation in WDM Cosmology

We investigate for the first time the effects of a Warm Dark Matter (WDM) power spectrum on the statistical properties of galaxies using a semi-analytic model of galaxy formation. The WDM spectrum we adopt as a reference case is suppressed - compared to the standard Cold Dark Matter (CDM) case - below a cut-off scale ~ 1 Mpc corresponding (for thermal relic WDM particles) to a mass m_X=0.75 keV. This ensures consistency with present bounds provided by the microwave background WMAP data and by the comparison of hydrodynamical N-body simulations with observed Lyman-{\alpha} forest. We run our fiducial semi-analytic model with such a WDM spectrum to derive galaxy luminosity functions (in B, UV, and K bands) and the stellar mass distributions over a wide range of cosmic epochs, to compare with recent observations and with the results in the CDM case. The predicted color distribution of galaxies in the WDM model is also checked against the data. When compared with the standard CDM case, the luminosity and stellar mass distributions we obtain assuming a WDM spectrum are characterized by: i) a flattening of the faint end slope and ii) a sharpening of the cutoff at the bright end for z \lesssim 0.8. We discuss how the former result is directly related to the smaller number of low-mass haloes collapsing in the WDM scenario, while the latter is related to the smaller number of satellite galaxies accumulating in massive haloes at low redshift, thus suppressing the accretion of small lumps on the central, massive galaxies. These results shows how a adopting a WDM power spectrum may contribute to solve two major problems of CDM galaxy formation scenarios, namely, the excess of predicted faint (low mass) galaxies at low and - most of all - high redshifts, and the excess of bright (massive) galaxies at low redshifts.Comment: 13 pages, 6 figures; accepted for publication in MNRAS. Added new reference

Determination of Gender in the Pearl Oyster Pinctada margaritifera

The pearl industry in French Polynesia is based on exploitation of natural stocks of the black-lip pearl oyster (Pinctada margaritifera); it generates an annual turnover of 90 million euros. Improvements in pearl quality need genetic studies to improve the populations. This pearl oyster is a protandric species, where the sex-ratio normally is biased towards males. There is an increasing interest in gender control to find the mechanisms to augment female proportions for management purposes. This review summarizes information on exogenous and endogenous factors regulating gender in this and other bivalves and concludes that P. margaritifera is a protandric hermaphrodite, developing as a male during the first two years and without evidence of an effect from abiotic and biotic factors on gender during this phase. Later, pearl oysters progressively change to females, reaching a sex ratio close to 1:1 in specimens >8 years; at this stage, gender is apparently influenced by environmental parameters, but particularly by stress. Future research should seek to accurately determine the effect of temperature and food on sex ratios. Studies should be performed to characterize genes responsible for expression of gender. The use of hormones is a path that might be explored to influence the gender of pearl oysters