126 research outputs found
The VIMOS Public Extragalactic Redshift Survey (VIPERS). Environmental effects shaping the galaxy stellar mass function
No full textO.C. acknowledges the support from grants ASI-INAF I/023/12/0 “Attività relative alla fase B2/C per la missione Euclid”. L.G. and B.R.G. acknowledge support of the European Research Council through the Darklight E.R.C. Advanced Research Grant (# 291521). O.L.F. acknowledges the support of the European Research Council through the EARLY ERC Advanced Research Grant (# 268107). A.P., K.M., and J.K. have been supported by the National Science Centre (grants UMO-2012/07/B/ST9/04425 and UMO-2013/09/D/ST9/04030), the Polish-Swiss Astro Project (co-financed by a grant from Switzerland through the Swiss Contribution to the enlarged European Union). R.T. acknowledges financial support from the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement n. 202686. E.B., F.M., and L.M. acknowledge the support from grants ASI-INAF I/023/12/0 and PRIN MIUR 2010-2011. LM also acknowledges financial support from PRIN INAF 2012. Y.M. acknowledges support from CNRS/INSU (Institut National des Sciences de l’Univers) and the Programme National Galaxies et Cosmologie (PNCG).We exploit the first public data release of VIPERS to investigate environmental effects in the evolution of galaxies between z ~ 0.5 and 0.9. The large number of spectroscopic redshifts (more than 50 000) over an area of about 10 deg2 provides a galaxy sample with high statistical power. The accurate redshift measurements (σz = 0.00047(1 + zspec)) allow us to robustly isolate galaxies living in the lowest and highest density environments (δ 4, respectively) as defined in terms of spatial 3D density contrast δ. We estimate the stellar mass function of galaxies residing in these two environments and constrain the high-mass end (ℳ ≳ 1011 ℳ⊙) with unprecedented precision. We find that the galaxy stellar mass function in the densest regions has a different shape than was measured at low densities, with an enhancement of massive galaxies and a hint of a flatter (less negative) slope at z< 0.8. We normalise each mass function to the comoving volume occupied by the corresponding environment and relate estimates from different redshift bins. We observe an evolution of the stellar mass function of VIPERS galaxies in high densities, while the low-density one is nearly constant. We compare these results to semi-analytical models and find consistent environmental signatures in the simulated stellar mass functions. We discuss how the halo mass function and fraction of central/satellite galaxies depend on the environments considered, making intrinsic and environmental properties of galaxies physically coupled, hence difficult to disentangle. The evolution of our low-density regions is described well by the formalism introduced by Peng et al. (2010, ApJ, 721, 193), and is consistent with the idea that galaxies become progressively passive because of internal physical processes. The same formalism could also describe the evolution of the mass function in the high density regions, but only if a significant contribution from dry mergers is considered.Peer reviewe
Nahal Ein Gev I : A Late Upper Palaeolithic Site by the Sea of Galilee, Israel
No full textThis paper presents the results of renewed excavations at the late Upper Palaeolithic site of Nahal Ein Gev 1 on the eastern margins of the Sea of Galilee. The lithic assemblage is characterised by a chunky flake technology produced using a hard hammer. The tool repertoire is heavily dominated by burins on Clactonian truncations and notches. Other tool classes are not especially standardised, and there is a small microlithic component. The results broadly conform to those of the previous excavations and corroborate that the described assemblage is indeed representative of the site as a whole. It seems almost certain that the previously described skeletal remains are indeed integral to the site, which appears to represent a foraging camp as indicated by the broad range offaunal remains. The assemblage is placed within the framework of the later Upper Palaeolithic "Atlitian " entity. It is concluded that the techno-typolog- ical configuration of this and comparable Atlitian assemblages bear little, if any, resemblance to Levantine Aurignacian industries.Sont présentés ici les résultats de fouilles qui furent reprises sur le gisement paléolithique supérieur tardif de Nahal Ein Gev l, situé sur la rive orientale du lac de Tibériade. L 'assemblage lithique est caractérisé par un débitage sommaire à éclats grossiers obtenu à l 'aide d'un percuteur dur. Parmi les outils prédominent les burins sur troncatures et encoches clactoniennes. Les autres classes d 'outils n 'apparaissent pas spécialement standardisées mais comportent une petite composante microlithique. Ces résultats recoupent largement ceux obtenus lors des fouilles antérieures et montrent bien que l 'assemblage décrit est représentatif de l 'ensemble du site. Il semble presque certain que les restes humains qui avaient été signalés appartiennent bien au site ; celui-ci devait être un camp de prédateurs comme l 'indique la grande variété des restes d 'animaux recueillis.
Dans le cadre du Paléolithique supérieur tardif l'assemblage appartient à l 'entité Atlitienne comme le montrent aussi bien la technologie que la typologie alors qu 'ils n 'offrent peu, si ce n 'est aucune, ressemblance avec les industries de l'Aurignacien levantin.Belfer-Cohen Anna, Davidzon Angela, Goring-Morris A. N., Lieberman Daniel E., Spiers M. Nahal Ein Gev I : A Late Upper Palaeolithic Site by the Sea of Galilee, Israel. In: Paléorient, 2004, vol. 30, n°1. pp. 25-45
Galaxy evolution in the VIMOS public extragalactic redshift survey (VIPERS)
No full textIn this work I present the first measurements of the galaxy stellar mass function (GSMF) from the first public release of the VIPERS catalogue, containing ∼55,000 objects.
First, I present the survey design, its scientific goal, the redshift measurements and validation. Then, I provide details about the estimate of galaxy stellar masses, star formation rates, and other physical quantities. I derive the GSMF of different galaxy types (e.g. active and passive galaxies) and as a function of the environment (defined through the local galaxy density contrast). These estimates represent new observational evidence useful to characterise the mechanism of galaxy evolution
Uma viagem experimental: A criação de uma obra de dramaturgia histórica com apoio da inteligência artificial
No full textThis essay explores the hopeful, though often frustrating, aspects of using artificial intelligence (AI) technology as a tool in service of the writer to co-create original texts. To do so, we carried out an experiment that aimed to achieve the manuscript of the first ten pages of a historical play, starting from a blank page, which I completed and titled Caracol. Through my exploration process, I navigated and tested the AI, seeking to define its possible role as a useful collaborator in the creative process. After much trial and error, I concluded that AI is a helpful asset that will be added to my tools, but with restricted and limited power. The AI proved its worth as a good coach and editor, and as a technology capable of working by following my guidelines on archival materials in order to create historical fiction, in this case, of dramatic nature. The following essay examines its potential and value in shaping original works despite its multiple shortcomings and its detractors.Este ensayo explora los aspectos esperanzadores, aunque a menudo frustrantes, del uso de la inteligencia artificial (IA) como una herramienta al servicio del escritor para co-crear y construir textos originales. Para ello, realizamos un experimento que tuvo como meta producir el manuscrito de las diez primeras páginas de una obra de dramaturgia histórica, partiendo de la página en blanco, la misma que concluí y terminé titulando Caracol. A través de mi proceso de exploración, navegué y probé las funciones de la IA, buscando definir su posible papel como colaborador útil dentro del proceso creativo. Después de mucho ensayo y error, pude concluir que la IA es un apoyo que se sumará a mis herramientas, pero con un poder restringido y acotado. Esta demostró poder funcionar a manera de un buen entrenador y editor, así como ser una tecnología capaz de trabajar con base en mis lineamientos sobre los materiales de archivo a fin de crear una ficción histórica que, en este caso, fue dramatúrgica. El siguiente ensayo examina su potencialidad y valor para dar forma a obras originales a pesar de sus múltiples carencias y de sus detractores.Este ensaio explora os aspectos esperançosos, embora muitas vezes frustrantes, de usar a tecnologia da inteligência artificial (IA) como uma ferramenta a serviço do escritor para co-criar e construir textos originais. O experimento teve como objetivo alcançar um manuscrito das dez primeiras páginas de uma peça histórica partindo de uma página em branco, a mesma que concluí e terminei intitulando Caracol. Através do meu processo de exploração, naveguei e testei a IA procurando definir seu possível papel como um colaborador útil do processo criativo. Depois de muito ensaio e erro, concluí que a IA é um apoio que se somará às minhas ferramentas com poder restritivo e limitado. No entanto, ela provou ser uma boa treinadora e editora, uma tecnologia capaz de trabalhar seguindo minhas orientações sobre materiais de arquivo a fim de criar uma ficção histórica, no meu caso dramatúrgica. O ensaio seguinte examina seu potencial e valor para dar forma a obras originais apesar de suas múltiplas carências e de seus detratores
Phenotypic Heterogeneity among <i>GBA</i> p.R202X Carriers in Lewy Body Spectrum Disorders
No full textWe describe the clinical and neuropathologic features of patients with Lewy body spectrum disorder (LBSD) carrying a nonsense variant, c.604C>T; p.R202X, in the glucocerebrosidase 1 (GBA) gene. While this GBA variant is causative for Gaucher’s disease, the pathogenic role of this mutation in LBSD is unclear. Detailed neuropathologic evaluation was performed for one index case and a structured literature review of other GBA p.R202X carriers was conducted. Through the systematic literature search, we identified three additional reported subjects carrying the same GBA mutation, including one Parkinson’s disease (PD) patient with early disease onset, one case with neuropathologically-verified LBSD, and one unaffected relative of a Gaucher’s disease patient. Among the affected subjects carrying the GBA p.R202X, all males were diagnosed with Lewy body dementia, while the two females presented as PD. The clinical penetrance of GBA p.R202X in LBSD patients and families argues strongly for a pathogenic role for this variant, although presenting with a striking phenotypic heterogeneity of clinical and pathological features
Pearsonites, a new Paleogene planktonic foraminiferal genus for the Broedermanni lineage
No full textThe new genus Pearsonites with P. broedermanni as type species is herein formalized to accommodate the early to middle Eocene globorotaliform taxa of the broedermanni lineage with a wall texture bearing muricae. Our analysis of specimens from the Pacific Ocean reveals a substantial similarity in wall structure with the genus Acarinina. In particular, the development and organization of the muricae, the hourglass shape of the pores, and the morphological features suggest that Pearsonites nov. gen. evolved from Acarinina in the late Paleocene. Herein we group three species previously considered morphologically and evolutionarily related to the Paleocene genus Igorina Davidzon, 1976, within Pearsonites nov. gen.: P. broedermanni (Cushman & Bermudez, 1949), P. lodoensis (Mallory, 1959), and P. anapetes (Blow, 1979). Species assigned to Pearsonites nov. gen. are relatively common in the stratigraphic interval from the late Paleocene (Zone P5) to the middle Eocene (Zone E9)
Hubble Frontier Field Clusters and Their Parallel Fields:Photometric and Photometric Redshift Catalogs
No full textWe present a multiband analysis of the six Hubble Frontier Field clusters and their parallel fields, producing catalogs with measurements of source photometry and photometric redshifts. We release these catalogs to the public along with maps of intracluster light and models for the brightest galaxies in each field. This rich data set covers a wavelength range from 0.2 to 8 mu m, utilizing data from the Hubble Space Telescope, Keck Observatories, Very Large Telescope array, and Spitzer Space Telescope. We validate our products by injecting into our fields and recovering a population of synthetic objects with similar characteristics to those in real extragalactic surveys. The photometric catalogs contain a total of over 32,000 entries, with 50% completeness at a threshold of mag(AB) similar to 29.1 for unblended sources and mag(AB) similar to 29 for blended ones, in the IR-weighted detection band. Photometric redshifts were obtained by means of template fitting and have an average outlier fraction of 10.3% and scatter sigma = 0.067 when compared to spectroscopic estimates. The software we devised, after being tested in the present work, will be applied to new data sets from ongoing and future surveys.</p
COSMOS2020: Manifold Learning to Estimate Physical Parameters in Large Galaxy Surveys
No full textInternational audienceWe present a novel method to estimate galaxy physical properties from spectral energy distributions (SEDs), alternate to template fitting techniques and based on self-organizing maps (SOM) to learn the high-dimensional manifold of a photometric galaxy catalog. The method has been previously tested with hydrodynamical simulations in Davidzon et al. (2019) while here is applied to real data for the first time. It is crucial for its implementation to build the SOM with a high quality, panchromatic data set, which we elect to be the "COSMOS2020" galaxy catalog. After the training and calibration steps with COSMOS2020, other galaxies can be processed through SOM to obtain an estimate of their stellar mass and star formation rate (SFR). Both quantities result to be in good agreement with independent measurements derived from more extended photometric baseline, and also their combination (i.e., the SFR vs. stellar mass diagram) shows a main sequence of star forming galaxies consistent with previous studies. We discuss the advantages of this method compared to traditional SED fitting, highlighting the impact of having, instead of the usual synthetic templates, a collection of empirical SEDs built by the SOM in a "data-driven" way. Such an approach also allows, even for extremely large data sets, an efficient visual inspection to identify photometric errors or peculiar galaxy types. Considering in addition the computational speed of this new estimator, we argue that it will play a valuable role in the analysis of oncoming large-area surveys like Euclid or the Legacy Survey of Space and Time at the Vera Cooper Rubin Telescope
Recensioni
No full textMassimo Piattelli Palmarini, Le scienze cognitive classiche: un panorama di Daniela MarioArthur L. Costa, Bena Kallick, Habits of Mind: A developmental series, Association Supervision for Curriculum Development di Daniele MorselliSarah-Jayne Blakemore, Uta Frith, The Learning Brain: Lessons for Education di Giuseppe LongoXenia Chryssochoou, Cultural diversity. Its social psychologydi Francesca LazzariCarl Bereiter, Education and mind in the knowledge age di Francesco Caviglia Isabel Beck, Margareth McKeown, Improving Comprehension with Questioning the Author: A Fresh and Expanded View of a Powerful Approach di Irith Davidzo
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