Young and Intermediate-age Distance Indicators

Distance measurements beyond geometrical and semi-geometrical methods, rely mainly on standard candles. As the name suggests, these objects have known luminosities by virtue of their intrinsic proprieties and play a major role in our understanding of modern cosmology. The main caveats associated with standard candles are their absolute calibration, contamination of the sample from other sources and systematic uncertainties. The absolute calibration mainly depends on their chemical composition and age. To understand the impact of these effects on the distance scale, it is essential to develop methods based on different sample of standard candles. Here we review the fundamental properties of young and intermediate-age distance indicators such as Cepheids, Mira variables and Red Clump stars and the recent developments in their application as distance indicators.Comment: Review article, 63 pages (28 figures), Accepted for publication in Space Science Reviews (Chapter 3 of a special collection resulting from the May 2016 ISSI-BJ workshop on Astronomical Distance Determination in the Space Age

Espécies do gênero Munida Leach (Crustacea, Decapoda, Galatheidae), distribuídas na costa do Brasil Species of the genus Munida Leach (Crustacea, Decapoda, Galatheidae) with distribution in the Brazilian coast

<abstract language="eng">The purpose of this work is to analyse the taxonomy and distributional patterns of the species of the genus Munida Leach, 1820 which occur along the Brazilian coast. The species of Munida present some peculiar characteristics, rarely found in any other marine group. They live in groups with great number of individuals (gregariousness) and with several species found together in the same population (sintopy). In addition, they exhibit a great degree of intraspeciftc variation and, paradoxally, a little variability among the species. These factors make a better understanding of the systematics of this group very difficult. In the present study the utilization of non variable characters was emphasized. As a corollary of this study, "species-complexes" were defined including groups of species morphologically very similar but yet well characterized. Sixteen species with distribution along the Brazilian coast were studied. An identification key is provided. A general discussion where the main problems on taxonomy and distributional patterns of species were analysed was done