Fitting the integrated Spectral Energy Distributions of Galaxies

Fitting the spectral energy distributions (SEDs) of galaxies is an almost universally used technique that has matured significantly in the last decade. Model predictions and fitting procedures have improved significantly over this time, attempting to keep up with the vastly increased volume and quality of available data. We review here the field of SED fitting, describing the modelling of ultraviolet to infrared galaxy SEDs, the creation of multiwavelength data sets, and the methods used to fit model SEDs to observed galaxy data sets. We touch upon the achievements and challenges in the major ingredients of SED fitting, with a special emphasis on describing the interplay between the quality of the available data, the quality of the available models, and the best fitting technique to use in order to obtain a realistic measurement as well as realistic uncertainties. We conclude that SED fitting can be used effectively to derive a range of physical properties of galaxies, such as redshift, stellar masses, star formation rates, dust masses, and metallicities, with care taken not to over-interpret the available data. Yet there still exist many issues such as estimating the age of the oldest stars in a galaxy, finer details ofdust properties and dust-star geometry, and the influences of poorly understood, luminous stellar types and phases. The challenge for the coming years will be to improve both the models and the observational data sets to resolve these uncertainties. The present review will be made available on an interactive, moderated web page (sedfitting.org), where the community can access and change the text. The intention is to expand the text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics & Space Scienc

Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV

Peer reviewe

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

Charged-particle nuclear modification factors in PbPb and pPb collisions at √=sNN=5.02 TeV

The spectra of charged particles produced within the pseudorapidity window |η| < 1 at √ sNN = 5.02 TeV are measured using 404 µb −1 of PbPb and 27.4 pb−1 of pp data collected by the CMS detector at the LHC in 2015. The spectra are presented over the transverse momentum ranges spanning 0.5 < pT < 400 GeV in pp and 0.7 < pT < 400 GeV in PbPb collisions. The corresponding nuclear modification factor, RAA, is measured in bins of collision centrality. The RAA in the 5% most central collisions shows a maximal suppression by a factor of 7–8 in the pT region of 6–9 GeV. This dip is followed by an increase, which continues up to the highest pT measured, and approaches unity in the vicinity of pT = 200 GeV. The RAA is compared to theoretical predictions and earlier experimental results at lower collision energies. The newly measured pp spectrum is combined with the pPb spectrum previously published by the CMS collaboration to construct the pPb nuclear modification factor, RpA, up to 120 GeV. For pT > 20 GeV, RpA exhibits weak momentum dependence and shows a moderate enhancement above unity

Passionflower supplementation in diets of Japanese qualis at rearing and laying periods Efeitos da utilização de passiflora em rações de codornas japonesas nas fases de recria e postura

The objective of this study was to assess the effect of the inclusion of passionflower (Passiflora alata) in diets on performance, behavior, heterophil/lymphocyte ratio (H/L), corticosterone plasma levels (CPL) and immune response of quails. The study was carried out using 192 birds, distributed in randomized blocks with 4 diets (0, 125, 250 and 375 and 0, 250, 500 and 750 mg of passionflower/kg of feed for the rearing and laying period, respectively), 8 replicates and 6 birds per experimental unit. The rearing period began when birds were 28 days of age and it lasted for 15 days. In this phase, it was evaluated daily feed intake, daily weight gain, feed conversion, viability, tonic immobility time, intensity of injuries, behavior, heterophil/lymphocyte ratio, and corticosterone plasma levels. Laying phase started when birds were 43 days of age and it finished when they were 140 days of age; it was compesed of six 14-day cycles in which it evaluated feed intake, feed conversion, egg production and quality, viability, tonic immobility time, intensity of injuries, behavior, heterophil/lymphocyte ratio, corticosterone plasma levels and immune response. In the rearing period, the use of passionflower in the diet of quails influenced the behavioral parameters, and the birds became calmer, mainly at the dosage of 375 mg/kg of ration. However, in the laying period, passionflower was efficient in reducing stress in the quails, and the most promising results are observed when higher dosages of the phytotherapic were applied. Nevertheless, the dose of 750 mg/kg of feeeding reduces egg production, though it does not influence quality of eggs neither immune response of the quails.<br>Objetivou-se avaliar o efeito da inclusão de passiflora na ração sobre o desempenho, o comportamento, a relação heterófilo/linfócito, a concentração plasmática de corticosterona e a imunidade de codornas. Foram utilizadas 192 aves, distribuídas em blocos casualizados com 4 dietas (0, 125, 250 e 375, e 0, 250, 500 e 750 mg de passiflora/kg de ração nas fases de recria e postura, respectivamente), 8 repetições e 6 aves por parcela. A fase de recria iniciou-se aos 28 dias de idade das aves e teve duração de 15 dias. Nesta fase foram avaliados o consumo diário de ração, o ganho diário de peso, a conversão alimentar, a viabilidade, o tempo em imobilidade tônica, a intensidade de ferimentos, o comportamento, a relação heterófilo/linfócito e concentração plasmática de corticosterona. A fase de postura teve início quando as aves atingiram 43 dias de idade e seu término encerrou-se aos 140 dias de idade das aves; foi constituída de seis ciclos de 14 dias, nos quais foram avaliados o consumo de ração, a conversão alimentar, a produção e qualidade de ovos, a viabilidade, o tempo em imobilidade tônica, a intensidade de ferimentos, o comportamento, a relação herófilo/linfócito, a concentração plasmática de corticosterona e a resposta imunológica. Na fase de recria, o uso de passiflora na dieta de codornas influenciou os parâmetros comportamentais, tornando as aves mais calmas, principalmente na dosagem de 375 mg/kg de ração. Já na fase de postura, foi eficaz na redução do estresse das codornas, e os resultados mais promissores foram observados quando aplicadas as maiores dosagens do fitoterápico. A dosagem de 750 mg/kg de ração, no entanto, diminui a produção de ovos, embora não tenha influência na qualidade dos ovos nem a resposta imunológica das aves