The origin of the LMC stellar bar: clues from the SFH of the bar and inner disk

We discuss the origin of the LMC stellar bar by comparing the star formation histories (SFH) obtained from deep color-magnitude diagrams (CMDs) in the bar and in a number of fields in different directions within the inner disk. The CMDs, reaching the oldest main sequence turnoffs in these very crowded fields, have been obtained with VIMOS on the VLT in service mode, under very good seeing conditions. We show that the SFHs of all fields share the same patterns, with consistent variations of the star formation rate as a function of time in all of them. We therefore conclude that no specific event of star formation can be identified with the formation of the LMC bar, which instead likely formed from a redistribution of disk material that occurred when the LMC disk became bar unstable, and shared a common SFH with the inner disk thereafter. The strong similarity between the SFH of the center and edge of the bar rules out significant spatial variations of the SFH across the bar, which are predicted by scenarios of classic bar formation through buckling mechanisms.Comment: MNRAS Letters, accepte

On the Presence of Thermal SZ Induced Signal in the First Year WMAP Temperature Maps

Using available optical and X-ray catalogues of clusters and superclusters of galaxies, we build templates of tSZ emission as they should be detected by the WMAP experiment. We compute the cross-correlation of our templates with WMAP temperature maps, and interpret our results separately for clusters and for superclusters of galaxies. For clusters of galaxies, we claim 2-5 $\sigma$ detections in our templates built from BCS Ebeling et al. (1998), NORAS (Boehringer et al. 2000) and de Grandi et al. (1999) catalogues. In these templates, the typical cluster temperature decrements in WMAP maps are around 15-35 $\mu$K in the RJ range (no beam deconvolution applied). Several tests probing the possible influence of foregrounds in our analyses demonstrate that our results are robust against galactic contamination. On supercluster scales, we detect a diffuse component in the V & W WMAP bands which cannot be generated by superclusters in our catalogues (Einasto et al. 1994, 1997), and which is not present in the clean map of Tegmark, de Oliveira-Costa & Hamilton (2003). Using this clean map, our analyses yield, for Einasto's supercluster catalogues, the following upper limit for the comptonization parameter associated to supercluster scales: y_{SC} < 2.18 \time s 10^{-8} at the 95% confidence limit.Comment: MNRAS accepted. New section and minor changes include

Limits on Hot Intracluster Gas Contributions to the Tenerife Temperature Anisotropy Map

We limit the contribution of the hot intracluster gas, by means of the Sunyaev-Zel'dovich effect, to the temperature anisotropies measured by the Tenerife experiment. The data is cross-correlated with maps generated from the ACO cluster catalogue, the ROSAT PSPC catalogue of clusters of galaxies, a catalogue of superclusters and the HEAO 1 A-1 map of X-ray sources. There is no evidence of contamination by such sources at an rms level of $\sim 8\mu$K at 99% confidence level at $5^o$ angular resolution. We place an upper limit on the mean Comptonization parameter of $y \le 1.5\times 10^{-6}$ at the same level of confidence. These limits are slightly more restrictive than those previously found by a similar analysis on the COBE/DMR data and indicate that most of the signal measured by Tenerife is cosmological.Comment: To be published in ApJ (main journal

On the Number Density of Sunyaev-Zel'dovich Clusters of Galaxies

If the mean properties of clusters of galaxies are well described by the entropy-driven model, the distortion induced by the cluster population on the blackbody spectrum of the Cosmic Microwave Background radiation is proportional to the total amount of intracluster gas while temperature anisotropies are dominated by the contribution of clusters of about 10^{14} solar masses. This result depends marginally on cluster parameters and it can be used to estimate the number density of clusters with enough hot gas to produce a detectable Sunyaev-Zel'dovich effect. Comparing different cosmological models, the relation depends mainly on the density parameter Omega_m. If the number density of clusters could be estimated by a different method, then this dependence could be used to constrain Omega_m.Comment: 8 pages, 3 figures, submitted to ApJ Letter

Tomography of the Reionization Epoch with Multifrequency CMB Observations

We study the constraints that future multifrequency Cosmic Microwave Background (CMB) experiments will be able to set on the metal enrichment history of the Inter Galactic Medium at the epoch of reionisation. We forecast the signal to noise ratio for the detection of the signal introduced in the CMB by resonant scattering off metals at the end of the Dark Ages. We take into account systematics associated to inter-channel calibration, PSF reconstruction errors and innacurate foreground removal. We develop an algorithm to optimally extract the signal generated by metals during reionisation and to remove accurately the contamination due to the thermal Sunyaev-Zel'dovich effect. Although demanding levels of foreground characterisation and control of systematics are required, they are very distinct from those encountered in HI-21cm studies and CMB polarization, and this fact encourages the study of resonant scattering off metals as an alternative way of conducting tomography of the reionisation epoch. An ACT-like experiment with optimistic assumtions on systematic effects, and looking at clean regions of the sky, can detect changes of 3%-12% (95% c.l.) of the OIII abundance (with respect its solar value) in the redshift range $z\in$ [12,22], for reionization redshift $z_{\rm re}>10$. However, for $z_{\rm re} <10$, it can only set upper limits on NII abundance increments of $\sim$ 60% its solar value in the redshift range $z\in$ [5.5,9], (95% c.l.). These constraints assume that inter-channel calibration is accurate down to one part in $10^{4}$, which constitutes the most critical technical requirement of this method, but still achievable with current technology.Comment: 10 pages, 2 figures, submitted to Astrophysical Journal. Comments are welcom

Evidence of the missing baryons from the kinematic Sunyaev-Zeldovich effect in Planck data

Under the terms of the Creative Commons Attribution license.-- et al.We estimate the amount of the missing baryons detected by the Planck measurements of the cosmic microwave background in the direction of central galaxies (CGs) identified in the Sloan galaxy survey. The peculiar motion of the gas inside and around the CGs unveils values of the Thomson optical depth τT in the range 0.2-2×10-4, indicating that the regions probed around CGs contain roughly half of the total amount of baryons in the Universe at the epoch where the CGs are found. If baryons follow dark matter, the measured τT's are compatible with the detection of all of the baryons existing inside and around the CGs.C. H.-M. acknowledges the support of Ramón y Cajal Fellowship No. RyC-2011-08262, Marie Curie Career Integration Grant No. 294183, and Spanish Ministerio de Economía y Competitividad Project No. AYA2012-30789. Y.-Z. M thanks ERC for its support through Starting Grant No. 307209.Peer Reviewe

The galaxy cluster Ysz-Lx and Ysz-M relations from the WMAP 5-yr data

We use multifrequency matched filters to estimate, in the WMAP 5-year data, the Sunyaev-Zel'dovich (SZ) fluxes of 893 ROSAT NORAS/REFLEX clusters spanning the luminosity range Lx,[0.1-2.4]keV = 2 10^{41} - 3.5 10^{45} erg s^{-1}. The filters are spatially optimised by using the universal pressure profile recently obtained from combining XMM-Newton observations of the REXCESS sample and numerical simulations. Although the clusters are individually only marginally detected, we are able to firmly measure the SZ signal (>10 sigma) when averaging the data in luminosity/mass bins. The comparison between the bin-averaged SZ signal versus luminosity and X-ray model predictions shows excellent agreement, implying that there is no deficit in SZ signal strength relative to expectations from the X-ray properties of clusters. Using the individual cluster SZ flux measurements, we directly constrain the Y500-Lx and Y500-M500 relations, where Y500 is the Compton y-parameter integrated over a sphere of radius r500. The Y500-M500 relation, derived for the first time in such a wide mass range, has a normalisation Y*500=[1.60 pm 0.19] 10^{-3} arcmin^2 at M500=3 10^{14} h^{1} Msun, in excellent agreement with the X-ray prediction of 1.54 10^{-3} arcmin^2, and a mass exponent of alpha=1.79 pm 0.17, consistent with the self-similar expectation of 5/3. Constraints on the redshift exponent are weak due to the limited redshift range of the sample, although they are compatible with self-similar evolution.Comment: Version accepted for publication in Astronomy and Astrophysic

Global Antifungal Profile Optimization of Chlorophenyl Derivatives against Botrytis cinerea and Colletotrichum gloeosporioides

Twenty-two aromatic derivatives bearing a chlorine atom and a different chain in the para or meta position were prepared and evaluated for their in vitro antifungal activity against the phytopathogenic fungi Botrytis cinerea and Colletotrichum gloeosporioides. The results showed that maximum inhibition of the growth of these fungi was exhibited for enantiomers S and R of 1-(40-chlorophenyl)- 2-phenylethanol (3 and 4). Furthermore, their antifungal activity showed a clear structure-activity relationship (SAR) trend confirming the importance of the benzyl hydroxyl group in the inhibitory mechanism of the compounds studied. Additionally, a multiobjective optimization study of the global antifungal profile of chlorophenyl derivatives was conducted in order to establish a rational strategy for the filtering of new fungicide candidates from combinatorial libraries. The MOOPDESIRE methodology was used for this purpose providing reliable ranking models that can be used later

El Paleolítico Medio en el territorio valenciano y la variabilidad tecno-económica de la Cova del Bolomor

En el presente artículo se exponen las principales características de las industrias líticas del Paleolítico Medio en el territorio valenciano. Se hace especial hincapié en la variabilidad tecno-económica observada en la secuencia estratigráfica de la Cova del Bolomor. Con dicho análisis se pretende contribuir al establecimiento de los rasgos evolutivos de las industrias asociadas a los grupos de neandertales. En este sentido, el estudio pone de manifiesto que en estas sociedades se produjo, en los momentos finales, cierto progreso tecnológico, en un contexto arqueológico en el que es difícil precisar si hubo, o no, influencia externa o aculturación por parte de las poblaciones de cromañones en el territorio valenciano.En el present article s'exposen les principals característiques de les indústries lítiques del Paleolític Mitjà en el territori valencià. Es posa especial atenció a la variabilitat tecno-econòmica observada en la seqüència estratigràfica de la Cova del Bolomor. Amb aquesta anàlisi es pretén contribuir a l'establiment dels trets evolutius de les indústries associades als grups de neandertals. En aquest sentit, l'estudi posa de manifest que en aquestes societats es va produir, en els moments finals, un cert progrés tecnològic, en un context arqueològic en el qual és difícil precisar si va haver-hi, o no, influència externa o aculturació per part de les poblacions de cromanyons en el territori valencià.Dans l'article ci-dessous, s'exposent les principales caractéristiques des industries lithiques du Paléolithique Moyen dans le territoire valencien. On veut mettre en relief la variabilité techno-économique observée dans la séquence stratigraphique de la Cova del Bolomor. Avec cette analyse, on cherche à établir les traits évolutifs des industries associées aux groupes néandertaliens. Dans ce sens, l'étude met en relief que ces sociétés ont probablement connu, dans un dernier temps, un certain progrès technologique, dans un contexte archéologique où il est difficile de préciser s'il y a eu ou pas une influence externe ou une acculturation venue des populations cromagnones dans la région de Valence.In this paper main characteristics of the Middle Palaeolithic lithic industries from the territory of Valencia are presented. Particular attention is paid to the techno-economical variability of the archaeological record in Cova del Bolomor. This study aims to discuss the evolutionary features of Neanderthal industries; our analysis shows that there was some technological progress at the end of the Middle Palaeolithic, in an archaeological context in which it is uncertain whether or not there was external influence or acculturation from Cro-Magnon populations in the valencian territory