Surface Brightness Fluctuations from archival ACS images: a stellar population and distance study

We derive Surface Brightness Fluctuations (SBF) and integrated magnitudes in the V- and I-bands using Advanced Camera for Surveys (ACS) archival data. The sample includes 14 galaxies covering a wide range of physical properties: morphology, total absolute magnitude, integrated color. We take advantage of the latter characteristic of the sample to check existing empirical calibrations of absolute SBF magnitudes both in the I- and V-passbands. Additionally, by comparing our SBF and color data with the Teramo-SPoT simple stellar population models, and other recent sets of population synthesis models, we discuss the feasibility of stellar population studies based on fluctuation magnitudes analysis. The main result of this study is that multiband optical SBF data and integrated colors can be used to significantly constrain the chemical composition of the dominant stellar system in the galaxy, but not the age in the case of systems older than 3 Gyr. SBF color gradients are also detected and analyzed. These SBF gradient data, together with other available data, point to the existence of mass dependent metallicity gradients in galaxies, with the more massive objects showing a non--negligible SBF versus color gradient. The comparison with models suggests that such gradients imply more metal rich stellar populations in the galaxies' inner regions with respect to the outer ones.Comment: ApJ Accepte

THE BOTANICAL GARDEN \u201cBERNARDINO DA UCRIA\u201d IN THE NATURAL PARK OF THE NEBRODI (SICILY) AND ITS MISSION TO CONSERVE, EXPLOIT AND SPREAD LOCAL AGROBIODIVERTITY AND OFFICINAL PLANTS

In Sicily, the academic botanical gardens of Catania, Messina and Palermo have been historically exerting a multiplicity of activities ranging from maintenance of ex situ collections to plant conservation policy, practice and ecological restoration, along with more traditional functions related to education and academic research. In the last decade\u2019s, two new botanical gardens the \u201cNuova Gussonea\u201d and the \u201cBernardino da Ucria, were created in Sicily, with the aim to play more delimited, yet modern and complementary roles. The garden \u201cNuova Gussonea\u201d, within the Etna Natural Park, is mostly devoted to collect and preserve the native flora of the Mount Etna, with a special focus on endemic and rare plants and their promotion to a wider public. The garden \u201cBernardino da Ucria\u201d, in the Nebrodi Natural Park, is mainly specialized in promoting the local culture and to collect and preserve the agro-biodiversity of officinal plants in the Nebrodi territory. It is located in the homonymous village in the Messina district where the famous \u201cdemonstrator of plants\u201d and co founder of the Botanical Garden of Palermo University was born. Noteworthy, within Sicily the Nebrodi area is undoubtedly the widest and richest in traditional activities regarding agriculture, sheep farming and sylviculture, which produced an agrobiodiversity heritage often representative of individual community cultures. Initially promoted by Palermo University and sustained by the Nebrodi Regional Park, this garden comprises the \u201cBanca vivente del Germoplasma vegetale dei Nebrodi\u201d. Accessions conserved in vivo so far include cultivars of crops (Corylus, Pyrus, Malus, Prunus sp. pl, Ficus, Juglans), vegetables (Phaseolus and Lycopersicum) and officinal plants, that are in part representative of local agricultural practices. Among crops, the collections of Ficus, Pyrus and Corylus are remarkable; while among vegetables, the beans (Phaseolus) are represented by over 65 distinct cultivars, comprising 57 climbing and 8 dwarf species (1). Additionally, the garden\u2019s bank hosts several botanical collections unrelated to the local flora, representative of officinal and ornamental genus, such as Salvia, Helleborus, Paeonia and Camelia. The cryopreserved accessions so far encompass the bean cultivars, mainly found within the Nebrodi Park area. The aim of this particular collection is to further exploit the local agricultural and food heritage by recovering and spreading among local farmers of autochthonous cultivars under extinction risk. Moreover, the garden has recently been equipped with a molecular biology laboratory, performing studies on the genetic diversity of the accessions, as well as activities instrumental to the creation of a related DNA bank, interconnected with the Palermo Botanical garden bank (HBP-Bank). In 2011, the botanical garden of Ucria hosted the Summer School \u201cKnowledge, conservation and management of plant biodiversity of the Mediterranean mountain systems\u201d, organized by Palermo University together with OPTIMA, and financially sponsored by the Nebrodi Park. Similarly, the Summer School \u201cManagement of plant biodiversity in the Mediterranean: ex situ conservation and germplasm banks\u201d will be held in 2016. The activities of the new Ucria botanical garden and its germplasm bank, is supported by a dedicated Consortium, established by the Nebrodi Park together with Palermo University. The botanical garden \u201cBernardino da Ucria\u201d is open to public in the spring and summer period. It is also offering didactic visits for educational purposes to several schools

Awareness of energy drink intake guidelines and associated consumption practices: a cross-sectional study

BACKGROUND: Despite concern regarding harms of energy drink (ED) consumption, no research has been conducted to determine awareness and compliance with ED intake guidelines displayed on product packaging in Australia (a novel approach internationally). METHODS: A convenience sample of 1922 people completed an online survey. Participants reported their knowledge of maximum recommended daily ED intake according to Australian guidelines. RESULTS: Guideline awareness was reported by 38, 23 and 19 % of past year consumers, lifetime, and non-consumers, respectively. Amongst past year consumers, \u27accurate estimators\u27 reported greater ED intake and were more likely to exceed intake guidelines and consume alcohol mixed with ED (AmED). After controlling for demographics and frequency of use, guideline awareness predicted increased likelihood of exceeding guidelines in ED sessions, but was not associated with exceeding ED guidelines in AmED sessions. CONCLUSIONS: Australia is considered to have the most stringent regulatory approach to EDs internationally. However, advisory statements are not associated with greater awareness and compliance with intake guidelines. Failure to comply with standards for efficacious product labelling, and absence of broader education regarding guidelines, needs to be addressed

The Cepheids of NGC1866: A Precise Benchmark for the Extragalactic Distance Scale and Stellar Evolution from Modern UBVI Photometry

We present the analysis of multiband time-series data for a sample of 24 Cepheids in the field of the Large Magellanic Cloud cluster NGC1866. Very accurate BVI VLT photometry is combined with archival UBVI data, covering a large temporal window, to obtain precise mean magnitudes and periods with typical errors of 1-2% and of 1 ppm, respectively. These results represent the first accurate and homogeneous dataset for a substantial sample of Cepheid variables belonging to a cluster and hence sharing common distance, age and original chemical composition. Comparisons of the resulting multiband Period-Luminosity and Wesenheit relations to both empirical and theoretical results for the Large Magellanic Cloud are presented and discussed to derive the distance of the cluster and to constrain the mass-luminosity relation of the Cepheids. The adopted theoretical scenario is also tested by comparison with independent calibrations of the Cepheid Wesenheit zero point based on trigonometric parallaxes and Baade-Wesselink techniques. Our analysis suggests that a mild overshooting and/or a moderate mass loss can affect intermediate-mass stellar evolution in this cluster and gives a distance modulus of 18.50 +- 0.01 mag. The obtained V,I color-magnitude diagram is also analysed and compared with both synthetic models and theoretical isochrones for a range of ages and metallicities and for different efficiencies of core overshooting. As a result, we find that the age of NGC1866 is about 140 Myr, assuming Z = 0.008 and the mild efficiency of overshooting suggested by the comparison with the pulsation models.Comment: 13 pages, 10 figures, accepted in MNRAS (2016 January 14

A bag of tricks: Using proper motions of Galactic stars to identify the Hercules ultra-faint dwarf galaxy members

Hercules is the prototype of the ultra-faint dwarf (UFD) galaxies. To date, there are still no firm constraints on its total luminosity, due to the difficulty of disentangling Hercules bona-fide stars from the severe Galactic field contamination. In order to better constrain Hercules properties we aim at removing foreground and background contaminants in the galaxy field using the proper motions of the Milky Way stars and the colour-colour diagram. We have obtained images of Hercules in the rSloan, BBessel and Uspec bands with the Large Binocular Telescope (LBT) and LBC-BIN mode capabilities. The rSloan new data-set combined with data from the LBT archive span a time baseline of about 5 yr, allowing us to measure for the first time proper motions of stars in the Hercules direction. The Uspec data along with existing LBT photometry allowed us to use colour-colour diagram to further remove the field contamination. Thanks to a highly-accurate procedure to derive the rSloan-filter geometric distortion solution for the LBC-red, we were able to measure stellar relative proper motions to a precision of better than 5 mas yr^-1 down to rSloan=22 mag and disentangle a significant fraction (\>90\%) of Milky Way contaminants. We ended up with a sample of 528 sources distributed over a large portion of the galaxy body (0.12 deg^2). Of these sources, 171 turned out to be background galaxies and additional foreground stars, from the analysis of the Uspec - BBessel vs. BBessel - rSloan colour-colour diagram. This leaves us with a sample of 357 likely members of the Hercules UFD. We compared the cleaned colour-magnitude diagram (CMD) with evolutionary models and synthetic CMDs, confirming the presence in Hercules of an old population (t=12\pm 2 Gyr), with a wide spread in metallicity (-3.3\<[Fe/H]\<-1.8).Comment: 16 pages, 15 figures, 3 tables, accepted for publication in A&

Detection of Radial Surface Brightness Fluctuation and Color Gradients in elliptical galaxies with ACS

We study surface brightness fluctuations (SBF) in a sample of 8 elliptical galaxies using Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) data drawn from the Hubble Space Telescope (HST) archive. SBF magnitudes in the F814W bandpass, and galaxy colors from F814W, F435W, and F606W images -- when available -- are presented. Galaxy surface brightness profiles are determined as well. We present the first SBF--broadband color calibration for the ACS/WFC F814W bandpass, and (relative) distance moduli estimates for 7 of our galaxies. We detect and study in detail the SBF variations within individual galaxies as a probe of possible changes in the underlying stellar populations. Inspecting both the SBF and color gradients in comparison to model predictions, we argue that SBF, and SBF-gradients, can in principle be used for unraveling the different evolutionary paths taken by galaxies, though a more comprehensive study of this issue would be required. We confirm that the radial variation of galaxy stellar population properties should be mainly connected to the presence of radial chemical abundance gradients, with the outer galaxy regions being more metal poor than the inner ones.Comment: 47 pages, 13 figures, ApJ, accepte