1,721,358 research outputs found
A multiwavelength study of the star forming region IRAS 18544+0112
Get PDFAims. This work aims at investigating the molecular and infrared components in the
massive young stellar object (MYSO) candidate IRAS 18544+0112. The purpose is to
determine the nature and the origin of this infrared source.
Methods. To analyze the molecular gas towards IRAS 18544+0112, we have carried
out observations in a 9000
× 9000 region around l = 34. 69, b = –0. 65, using the
Atacama Submillimeter Telescope Experiment (ASTE) in the 12CO J=3–2, 13CO J=3–
2, HCO+J=4–3 and CS J=7–6 lines with an angular resolution of 2200. The infrared
emission in the area has been analyzed using 2MASS and Spitzer public data.
Results. From the molecular analysis, we find self-absorbed 12CO J=3–2 profiles, which
are typical in star forming regions, but we do not find any evidence of outflow activ-
ity. Moreover, we do not detect either HCO+J=4–3 or CS J=7–6 in the region, which
are species normally enhanced in molecular outflows and high density envelopes. The
12CO J=3–2 emission profile suggests the presence of expanding gas in the region. The
Spitzer images reveal that the infrared source has a conspicuous extended emission
bright at 8 μm with an evident shell-like morphology of 1.05 in size ( 1.4 pc at the
proposed distance of 3 kpc) that encircles the 24 μm emission. The non-detection of
ionized gas related to IRAS 18544+0112 together with the fact that it is still embedded
in a molecular clump suggest that IRAS 18544+0112 has not reached the UCHII re-
gion stage yet. Based on near infrared photometry we search for YSO candidates in the
region and propos that 2MASS 18565878+0116233 is the infrared point source associ-
ated with IRAS 18544+0112. Finally, we suggest that the expansion of a larger nearby
HII region, G034.8−0.7, might be related to the formation of IRAS 18544+0112.S.P. is grateful to the staff of ASTE for the support received during the observations,
especially to Juan Cort´es. S.P. acknowledges the support of Viviana Guzm´an during the observations. M.O.
is a doctoral fellow of CONICET, Argentina. S.P., S.C., G.C., and G.D. are members of the Carrera del
Investigador Cient´ıfico of CONICET, Argentina. This work was partially supported by Argentina grants
awarded by CONICET, UBA and ANPCYT. M.R. is supported by the Chilean Center for Astrophysics
FONDAP No. 15010003. M.R. and S.P. acknowledge support from FONDECYT N 1080335. This work has
made use of GLIMPSE and MIPSGAL data obtained with the Spitzer Space Telescope, which is operated
by the Jet Propulsion Laboratory, California Institute of Technology, under NASA contract 1407. We
also used data products from the Two Micron All Sky Survey, the NASA/IPAC Infrared Science Archive,
which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with
NAS
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
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
