Galaxy–galaxy lensing in the outskirts of CLASH clusters: constraints on local shear and testing mass–luminosity scaling relation

We present a selection of 24 candidate galaxy–galaxy lensing (GGL) identified from Hubble images in the outskirts of the massive galaxy clusters from the Cluster Lensing And Supernova survey with Hubble (CLASH) . These GGLs provide insights into the mass distributions at larger scales than the strong-lensing region in the cluster cores. We built parametric mass models for three of these GGLs showing simple lensing configurations, in order to assess the properties of their lens and its environment. We show that the local shear estimated from the GGLs traces the gravitational potential of the clusters at a radial distance of 1–2 arcmin, allowing us to derive their velocity dispersion. We also find a good agreement between the strength of the shear measured at the GGL positions through strong-lensing modelling and the value derived independently from a weak-lensing analysis of the background sources. Overall, we show the advantages of using single GGL events in the outskirts of clusters to robustly constrain the local shear, even when only photometric redshift estimates are known for the source. We argue that the mass–luminosity scaling relation of cluster members can be tested by modelling the GGLs found around them, and show that the mass parameters can vary up to ∼30 per cent between the cluster and GGL models assuming this scaling relation

A First Look at Spatially Resolved Balmer Decrements at 1.0<z<2.41.0<z<2.4 from JWST NIRISS Slitless Spectroscopy

We present the first results on the spatial distribution of dust attenuation at $1.0<z<2.4$ traced by the Balmer Decrement, H$\alpha$/H$\beta$, in emission-line galaxies using deep JWST NIRISS slitless spectroscopy from the CAnadian NIRISS Unbiased Cluster Survey (CANUCS). H$\alpha$ and H$\beta$ emission line maps of emission-line galaxies are extracted and stacked in bins of stellar mass for two grism redshift bins, $1.0<z_{grism}<1.7$ and $1.7<z_{grism}<2.4$. Surface brightness profiles for the Balmer Decrement are measured and radial profiles of the dust attenuation towards H$\alpha$, $A_{\mathrm{H}\alpha}$, are derived. In both redshift bins, the integrated Balmer Decrement increases with stellar mass. Lower mass ($7.6\leqslant$Log($M_{*}$/M$_{\odot}$)$<10.0$) galaxies have centrally concentrated, negative dust attenuation profiles whereas higher mass galaxies ($10.0\leqslant$Log($M_{*}$/M$_{\odot}$)$<11.1$) have flat dust attenuation profiles. The total dust obscuration is mild, with on average $0.07\pm0.07$ and $0.14\pm0.07$ mag in the low and high redshift bins respectively. We model the typical light profiles of star-forming galaxies at these redshifts and stellar masses with GALFIT and apply both uniform and radially varying dust attenuation corrections based on our integrated Balmer Decrements and radial dust attenuation profiles. If these galaxies were observed with typical JWST NIRSpec slit spectroscopy ($0.2\times0.5^{\prime\prime}$ shutters), on average, H$\alpha$ star formation rates (SFRs) measured after slit-loss corrections assuming uniform dust attenuation will overestimate the total SFR by $6\pm21 \%$ and $26\pm9 \%$ at $1.0\leqslant z < 1.7$ and $1.7\leqslant z < 2.4$ respectively.Comment: 7 pages, 5 figures, submitted to ApJ

Λ\LambdaCDM not dead yet: massive high-z Balmer break galaxies are less common than previously reported

Early JWST observations that targeted so-called double-break sources (attributed to Lyman and Balmer breaks at $z>7$), reported a previously unknown population of very massive, evolved high-redshift galaxies. This surprising discovery led to a flurry of attempts to explain these objects' unexpected existence including invoking alternatives to the standard $\Lambda$CDM cosmological paradigm. To test these early results, we adopted the same double-break candidate galaxy selection criteria to search for such objects in the JWST images of the CAnadian NIRISS Unbiased Cluster Survey (CANUCS), and found a sample of 19 sources over five independent CANUCS fields that cover a total effective area of $\sim60\,$arcmin$^2$ at $z\sim8$. However, (1) our SED fits do not yield exceptionally high stellar masses for our candidates, while (2) spectroscopy of five of the candidates shows that while all five are at high redshifts, their red colours are due to high-EW emission lines in star-forming galaxies rather than Balmer breaks in massive, evolved systems. Additionally, (3) field-to-field variance leads to differences of $\sim 1.5$ dex in the maximum stellar masses measured in the different fields, suggesting that the early single-field JWST observations may have suffered from cosmic variance and/or sample bias. Finally, (4) we show that the presence of even a single massive outlier can dominate conclusions from small samples such as those in early JWST observations. In conclusion, we find that the double-break sources in CANUCS are not sufficiently massive or numerous to warrant questioning the standard $\Lambda$CDM paradigm.Comment: V2: correction of display problem of Fig.1 in Chrome browser. Submitted to MNRAS, 10 pages (+4 in Appendix), 5 figures (+4), 1 table (+1

The Sparkler: Evolved High-Redshift Globular Clusters Captured by JWST

Using data from JWST, we analyze the compact sources ("sparkles") located around a remarkable $z_{\rm spec}=1.378$ galaxy (the "Sparkler") that is strongly gravitationally lensed by the $z=0.39$ galaxy cluster SMACS J0723.3-7327. Several of these compact sources can be cross-identified in multiple images, making it clear that they are associated with the host galaxy. Combining data from JWST's {\em Near-Infrared Camera} (NIRCam) with archival data from the {\em Hubble Space Telescope} (HST), we perform 0.4-4.4$\mu$m photometry on these objects, finding several of them to be very red and consistent with the colors of quenched, old stellar systems. Morphological fits confirm that these red sources are spatially unresolved even in strongly magnified JWST/NIRCam images, while JWST/NIRISS spectra show [OIII]5007 emission in the body of the Sparkler but no indication of star formation in the red compact sparkles. The most natural interpretation of these compact red companions to the Sparkler is that they are evolved globular clusters seen at $z=1.378$. Applying \textsc{Dense Basis} SED-fitting to the sample, we infer formation redshifts of $z_{form} \sim 7-11$ for these globular cluster candidates, corresponding to ages of $\sim 3.9-4.1$ Gyr at the epoch of observation and a formation time just $\sim$0.5~Gyr after the Big Bang. If confirmed with additional spectroscopy, these red, compact "sparkles" represent the first evolved globular clusters found at high redshift, could be amongst the earliest observed objects to have quenched their star formation in the Universe, and may open a new window into understanding globular cluster formation. Data and code to reproduce our results will be made available at \faGithub\href{https://niriss.github.io/sparkler.html}{http://canucs-jwst.com/sparkler.html}.Comment: Submitted to ApJL. Comments are welcome. Data and code to reproduce our results will be made available at niriss.github.io/sparkler.htm

The first large catalogue of spectroscopic redshifts in Webb's First Deep Field, SMACS J0723.3−-7327

We present a spectroscopic redshift catalogue of the SMACS J0723.3$-$7327 field ("Webb's First Deep Field") obtained from JWST/NIRISS grism spectroscopy and supplemented with JWST/NIRSpec and VLT/MUSE redshifts. The catalogue contains a total of 190 sources with secure spectroscopic redshifts, including 156 NIRISS grism redshifts, 123 of which are for sources whose redshifts were previously unknown. These new grism redshifts are secured with two or more spectroscopic features (64 sources), or with a single spectral feature whose identity is secured from the object's nine-band photometric redshift (59 sources). These are complemented with 17 NIRSpec and 48 MUSE redshifts, including six new NIRSpec redshifts identified in this work. In addition to the $z_{\rm cl}=0.39$ cluster galaxy redshifts (for which we provide $\sim$40 new NIRISS absorption-line redshifts), we also find three prominent galaxy overdensities at higher redshifts - at $z=1.1$, $z=1.4$, and $z=2.0$ - that were until now not seen in the JWST/NIRSpec and VLT/MUSE data. The paper describes the characteristics of our spectroscopic redshift sample and the methodology we have employed to obtain it. Our redshift catalogue is made available to the community at https://niriss.github.io/smacs0723.Comment: 19 pages, 13 figures, 3 appendices. Accepted for publication in MNRA

Grid'5000: a large scale and highly reconfigurable grid experimental testbed

Large scale distributed systems such as Grids are difficult to study from theoretical models and simulators only. Most Grids deployed at large scale are production plat-forms that are inappropriate research tools because of their limited reconfiguration, control and monitoring capa-bilities. In this paper, we present Grid’5000, a 5000 CPU nation-wide infrastructure for research in Grid computing. Grid’5000 is designed to provide a scientific tool for com-puter scientists similar to the large-scale instruments used by physicists, astronomers, and biologists. We describe the motivations, design considerations, architec-ture, control, and monitoring infrastructure of this experi-mental platform. We present configuration examples and performance results for the reconfiguration subsystem

The endocannabinoid system controls food intake via olfactory processes

Comment in Sensory systems: the hungry sense. [Nat Rev Neurosci. 2014] Inhaling: endocannabinoids and food intake. [Nat Neurosci. 2014]; International audience; Hunger arouses sensory perception, eventually leading to an increase in food intake, but the underlying mechanisms remain poorly understood. We found that cannabinoid type-1 (CB1) receptors promote food intake in fasted mice by increasing odor detection. CB1 receptors were abundantly expressed on axon terminals of centrifugal cortical glutamatergic neurons that project to inhibitory granule cells of the main olfactory bulb (MOB). Local pharmacological and genetic manipulations revealed that endocannabinoids and exogenous cannabinoids increased odor detection and food intake in fasted mice by decreasing excitatory drive from olfactory cortex areas to the MOB. Consistently, cannabinoid agonists dampened in vivo optogenetically stimulated excitatory transmission in the same circuit. Our data indicate that cortical feedback projections to the MOB crucially regulate food intake via CB1 receptor signaling, linking the feeling of hunger to stronger odor processing. Thus, CB1 receptor-dependent control of cortical feedback projections in olfactory circuits couples internal states to perception and behavior

Photometric redshift estimations in large multi-wavelength surveys and application to galaxy cluster property studies

The redshift is an observable quantity which is linked to both the distances that separate us from extragalactic sources and to the Universe’s cosmology. To constrain the nature of the dark universe (i.e., dark energy and dark matter) large cosmological surveys, such as the Euclid survey, require measuring redshifts for billions of galaxies. Such kind of mission must rely on photometric redshifts, which in return must have the best precision and accuracy possible. I this thesis, I worked on the validation and the improvements of the photometric redshift measurement methods planned for Euclid mission. I also explored novel methods to extract the photometry in large survey images, and to combine the data of different surveys in a configuration close to the expected Euclid one. Moreover, I investigated the possibility to use such kind of data to study the evolution of galaxies in dense environments

Blaise Pascal, Pensées de M. Pascal sur la religion et sur quelques autres sujets, qui ont esté trouvées aprés sa mort parmy ses papiers

Munie d’un achevé d’imprimer daté du 2 janvier 1670, l’édition originale des Pensées commença d’être diffusée une quinzaine de jours plus tard environ&nbsp;: le 21 janvier 1670, Gilbert de Choiseul du Plessis-Praslin, évêque de Comminges, l’un des prélats auxquels le livre avait été soumis pour approbation en 1669, écrivait à Florin Périer pour accuser réception du livre et remercier les éditeurs d’avoir pris en compte les «&nbsp;changements qui [lui avaient] paru nécessaires&nbsp;». L’exemplaire ici présenté est relié aux armes de Pierre-Daniel Huet (1630-1721) et est rendu très précieux par les notes de lecture qu’il y a laissées&nbsp;: éminent savant de l’Europe de son temps, doté d’une très vaste culture littéraire, historique et philosophique, Huet a marqué les passages qui l’ont le plus retenu par de nombreux soulignements dans le texte ou à sa marge, et développé aussi sa pensée dans des notes qui vont de brefs renvois bibliographiques à d’autres lectures jusqu’à des remarques critiques longues de plusieurs lignes. Au-delà des faits historiques qu’il oppose ponctuellement à Pascal en puisant à son immense érudition, Huet, allant droit au cœur du projet apologétique des Pensées , s’intéresse surtout au mode d’affirmation propre à la foi chrétienne&nbsp;: de là l’attention qu’il prête aux passages relatifs aux prophéties bibliques comme preuves scripturaires et à la question générale des rapports de la foi et de la raison. Sa lecture exprime un point de vue fidéiste très affirmé&nbsp;: Huet relève chez Pascal toutes les formules d’humiliation de la raison qui soulignent l’impuissance de celle-ci à établir une vérité en matière de foi. La conviction d’une disjonction radicale de la foi et de la raison l’amène aussi à instruire une critique de l’argument du pari, dans lequel il décèle un reste de rationalisme&nbsp;: l’argumentation pascalienne soumet à juste titre la raison à la foi, mais elle «&nbsp;suppose que cette soumission même doit dépendre de la raison&nbsp;; et il me semble au contraire que de soumettre la raison à la foi, est plutôt l’ouvrage de la foi que de la raison&nbsp;», note-t-il p.&nbsp;48, face à l’un des fragments de la liasse «&nbsp;Soumission et usage de la raison&nbsp;» (S. 205). Pour Huet, toute affirmation de l’existence de Dieu dans laquelle la raison aurait quelque part, fût-elle réduite à parier faute de pouvoir démontrer, revient à nier son absolue transcendance. Huet a inscrit la date du 23 février 1670 à la fin du volume. Elle se rapporte à l’acquisition du livre et non à sa lecture, qui, par l’unité d’écriture de l’annotation, paraît avoir été faite d’une traite et non par étapes successives. Or on relève parmi les notes une référence au second tome de la Recherche de la vérité de Malebranche, paru en 1675. Aussi la lecture de Huet est-elle sans doute contemporaine de la préparation de sa Demonstratio evangelica (1679), ouvrage qui partage avec les Pensées un même dessein d’apologie du christianisme mais, s’appuyant sur une histoire comparée des religions, le conduit selon des voies très différentes.téléchargeabl

Biblia. A.T. Números. Francés

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2012-2013Sign.: ã8, ê1, A-Z8, 2A-2F8, 2G