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Chemical Complexity in the Eu-enhanced Monometallic Globular NGC 5986
Get PDFNGC 5986 is a poorly studied but relatively massive Galactic globular cluster that shares several physical and morphological characteristics with "iron-complex" clusters known to exhibit significant metallicity and heavy-element dispersions. In order to determine whether NGC 5986 joins the iron-complex cluster class, we investigated the chemical composition of 25 red giant branch and asymptotic giant branch cluster stars using high-resolution spectra obtained with the Magellan-M2FS instrument. Cluster membership was verified using a combination of radial velocity and [Fe/H] measurements, and we found the cluster to have a mean heliocentric radial velocity of +99.76 km s(-1) (sigma = 7.44 km s(-1)). We derived a mean metallicity of [Fe/H] = -1.54 dex (sigma = 0.08 dex), but the cluster's small dispersion in [Fe/H] and low [La/Eu] abundance preclude it from being an iron-complex cluster. NGC 5986 has = +0.76 dex (sigma = 0.08 dex), which is among the highest ratios detected in a Galactic cluster, but the small [Eu/Fe] dispersion is puzzling because such high values near [Fe/H] similar to -1.5 are typically only found in dwarf galaxies exhibiting large [Eu/Fe] variations. NGC 5986 exhibits classical globular cluster characteristics, such as uniformly enhanced [alpha/Fe] ratios, a small dispersion in Fe-peak abundances, and (anti) correlated light-element variations. Similar to NGC 2808, we find evidence that NGC 5986 may host at least four to five populations with distinct light-element compositions, and the presence of a clear Mg-Al anticorrelation along with an Al-Si correlation suggests that the cluster gas experienced processing at temperatures. greater than or similar to 65-70 MK. However, the current data do not support burning temperatures exceeding similar to 100 MK. We find some evidence that the first-and second-generation stars in NGC 5986 may be fully spatially mixed, which could indicate that the cluster has lost a significant fraction of its original mass.National Aeronautics and Space Administration; Clay Fellowship; National Science Foundation [AST-0923160, AST-1312997, AST-1313045, AST-1412999, AST-1413755, AST-1313006]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Colour-magnitude diagrams of the inner halo globular clusters NGC 5986 and NGC 6712
Get PDFWe present V and I photometry for NGC 5986 and B and V for NGC 6712. NGC 5986 has a blue extended horizontal branch, while NGC 6712 has a composite red and blue horizontal branch, where the latter extends to unusual bluer colours. Both clusters have RR Lyrae. We derive a reddening E(B-V) ≈ 0.29 and a distance from the Sun dʘ ≈ 11.2 kpc for NGC 5986, and E(B-V) ≈ 0.33 and dʘ ≈ 7.9 kpc for NGC 6712. Their galactocentric distances of RGC = 5.2 and 3.6 kpc respectively, locate them in the inner halo; NGC 6712 could be considered to be located in the bulge. NGC 6712 has |z|≈ 500 pc, indicating that the cluster is crossing the disk. We estimate metallicities of [Fe/H] = -1.6 and -1.0 respectively for NGC 5986 and NGC 6712
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Cranium of <i>Mystromys albicaudatus</i> (skull DNMNH-5986, mandible DNMNH-8813), with scale bar of 1 cm.
No full textCranium of Mystromys albicaudatus (skull DNMNH-5986, mandible DNMNH-8813), with scale bar of 1 cm.</p
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Probability that householders (N = 5986) had created a hedgehog highway in relation to house type and house location.
No full textProbability that householders (N = 5986) had created a hedgehog highway in relation to house type and house location.</p
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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