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Mannix, W G, 18511
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/401357Surname: MANNIX. Given Name(s) or Initials: W G. Military Service Number or Last Known Location: 18511. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 14749.221003
Item: [2016.0049.33650] "Mannix, W G, 18511
IRAS 18511+0146: a proto Herbig Ae/Be cluster?
No full textContext: The evolution of a young protocluster depends on the relative spatial distribution and dynamics of both stars and gas.
Aims: We study the distribution and properties of the gas and stars surrounding the luminous (104 L⊙) protocluster IRAS 18511+0146.
Methods: IRAS 18511+0146 and the cluster associated with it has been investigated using the sub-millimetre (JCMT-SCUBA), infrared (Spitzer-MIPSGAL, Spitzer-GLIMPSE, Palomar) and radio (VLA) continuum data. Cluster simulations have been carried out in order to understand the properties of clusters as well as to compare with the observations.
Results: The central most obscured part of the protocluster coincident with the compact sub-millimetre source found with SCUBA is responsible for at least 2/3 of the total luminosity. A number of cluster members have been identified which are bright in mid infrared and show rising (near to mid infrared) spectral energy distributions suggesting that these are very young stellar sources. In the mid infrared 8.0 μm image, a number of filamentary structures and clumps are detected in the vicinity of IRAS 18511+0146.
Conclusions: Based on the luminosity and cluster size as well as on the evolutionary stages of the cluster members, IRAS 18511+0146 is likely to be protocluster with the most massive object being a precursor to a Herbig type star
IRAS 18511+0146: a proto Herbig Ae/Be cluster?
Get PDFContext. The evolution of a young protocluster depends on the relative spatial distribution and dynamics of both stars and gas.
Aims. We study the distribution and properties of the gas and stars surrounding the luminous (10^4 L_☉) protocluster IRAS 18511+0146.
Methods. IRAS 18511+0146 and the cluster associated with it has been investigated using the sub-millimetre (JCMT-SCUBA), infrared (Spitzer-MIPSGAL, Spitzer-GLIMPSE, Palomar) and radio (VLA) continuum data. Cluster simulations have been carried out in order to understand the properties of clusters as well as to compare with the observations.
Results. The central most obscured part of the protocluster coincident with the compact sub-millimetre source found with SCUBA is responsible for at least 2/3 of the total luminosity. A number of cluster members have been identified which are bright in mid infrared and show rising (near to mid infrared) spectral energy distributions suggesting that these are very young stellar sources. In the mid infrared 8.0 μm image, a number of filamentary structures and clumps are detected in the vicinity of IRAS 18511+0146.
Conclusions. Based on the luminosity and cluster size as well as on the evolutionary stages of the cluster members, IRAS 18511+0146 is likely to be protocluster with the most massive object being a precursor to a Herbig type star
Dust and gas environment of the young embedded cluster IRAS 18511+0146
Get PDFContext. Since massive and intermediate mass stars form in clusters, a comparative investigation of the environments of the young embedded cluster members can reveal significant information about the conditions under which stars form and evolve.
Aims. IRAS 18511+0146 is a young embedded (proto)cluster located at 3.5 kpc surrounding what appears to be an intermediate mass protostar. Here, we investigate the nature of cluster members (two of which are believed to be the most massive and luminous) using imaging and spectroscopy in the near and mid-infrared. In particular, we examine the three brightest mid-infrared objects, two of which are believed to be the most massive ones driving the luminosity of this region.
Methods. Near-infrared spectroscopy of nine objects (bright in K-bands) towards IRAS 18511+0146 has been carried out. Several cluster members have also been investigated in the mid-infrared using spectroscopic and imaging with VISIR on the VLT. Far-infrared images from the Herschel Hi-GAL survey have been used to construct the column density and temperature maps of the region.
Results. The brightest point-like object associated with IRAS 18511+0146 is referred to as S7 in the present work (designated UGPS J185337.88+015030.5 in the UKIRT Galactic Plane survey). S7 is likely the most luminous object in the cluster as it is bright at all wavelengths ranging from the near-infrared to millimetre. Seven of the nine objects show rising spectral energy distributions in the near-infrared, with four objects showing Br-γ emission. Three members: S7, S10 (also UGPS J185338.37+015015.3) and S11 (also UGPS J185338.72+015013.5) are bright in mid-infrared with diffuse emission being detected in the vicinity of S11 in PAH bands. Silicate absorption is detected towards these three objects, with an absorption maximum between 9.6 and 9.7 μm, large optical depths (1.8–3.2), and profile widths of 1.6−2.1μm. The silicate profiles of S7 and S10 are similar, in contrast to S11 (which has the largest width and optical depth). The cold dust emission peaks at S7, with temperature at 26 K and column density N(H2) ~ 7 × 1022 cm-2. The bolometric luminosity of IRAS 18511 region is L ~ 1.8 × 104L⊙. S7 is the main contributor to the bolometric luminosity, with L (S7) ≳104L⊙.
Conclusions. S7 is a high-mass protostellar object with ionised stellar winds, evident from the correlation between radio and bolometric luminosity, as well as the asymmetric Br-γ profile. The differences in silicate profiles of S7 and S11 could be due to different radiation environments as we believe the former to be more massive and in an earlier phase than the latter
3.4 Micron Feature on the Shoulder of Ice-Band Absorptions in Three Luminous Young Stellar Objects: IRAS 18511 0146, IRAS 21413 5442, and IRAS 04579 4703
Get PDFAn absorption feature at 3.4 lm has been detected in the long-wavelength wing of the 3.1 lm H2O ice feature in three young stellar objects: IRAS 18511+0146, IRAS 21413+5442, and IRAS 04579+4703. The profile of the 3.4 lm absorption in IRAS 18511+0146 has distinct subfeatures at 3.38, 3.41, and 3.48 lm and is not similar to those found in molecular clouds but is similar to those in the diffuse interstellar medium, such as the lines of sight toward the Galactic center and Cyg OB2 12. Spectropolarimetry of the 3.4 lm feature in IRAS 18511+0146 shows no excess polarization accompanying the feature, which is consistent with the observation toward the Galactic center source IRS 7 by Adamson et al.The 3.4 lm absorption in IRAS 18511+0146 probably occurs in the diffuse interstellar medium intervening in the line of sight to the molecular cloud where the H2O ice absorption occurs. Furthermore, the 3.4 lm absorption carrier seems to reside in a population of nonpolarizing grains in the diffuse interstellar medium, physically separate from other polarizing grains
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
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