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1
Kristensen, Juliette. "Making Ways of Seeing: A Conversation with Mike Dibb and Richard Hollis." Journal of Visual Culture 11, no. 2 (July 25, 2012): 181–95. http://dx.doi.org/10.1177/1470412912444228.
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In 1971, Stephen Hearst, head of the BBC Music and Arts department, commissioned John Berger to make a television series on topics of his choosing. With Mike Dibb, then a young producer/director in the department, Berger made the four-part television series Ways of Seeing. Following its success, BBC Publications commissioned Berger and Dibb to turn the television programme into a book, a project for which Richard Hollis, a graphic designer Berger had previously worked with on the magazine New Society and his novel G., was brought in. Together with script consultant Chris Fox and artist Sven Blomberg, this group produced the book Ways of Seeing, jointly published by the BBC and Penguin Books in 1972. In this conversation with Juliette Kristensen, Mike Dibb and Richard Hollis discuss the history of the making of the television series and the book, Ways of Seeing.
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Downes, Cathy. "Australian defense strategy: The Dibb report." Defense Analysis 3, no. 1 (March 1987): 77–79. http://dx.doi.org/10.1080/07430178708405279.
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Ran, C. J. Oxenbould. "A Perspective on the Dibb Review." Maritime Studies 1986, no. 30 (July 1986): 11–14. http://dx.doi.org/10.1080/07266472.1986.11733440.
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Suter, Keith D. "Australia's defence debate: The dibb report." RUSI Journal 132, no. 4 (December 1987): 55–62. http://dx.doi.org/10.1080/03071848708522807.
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Mack, Andrew. "Defence versus offence: The Dibb report and its critics." Australian Outlook 41, no. 1 (April 1987): 3–9. http://dx.doi.org/10.1080/10357718708444925.
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Swaab, Peter. "The Line of Beauty." Film Quarterly 60, no. 3 (2007): 10–15. http://dx.doi.org/10.1525/fq.2007.60.3.10.
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ABSTRACT The BBC TV adaptation of Alan Hollinghurst's Booker Prize-winning 2004 novel of Aids and Thatcherism was undertaken by Andrew Davies, best known for his version of Pride and Prejudice. Directed by Saul Dibb, The Line of Beauty's depiction of 1980s London is appropriate to both to its source and costume-drama conventions.
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Cha, Victor D. "America's Asian Alliancesedited by Robert D. Blackwill and Paul Dibb." Political Science Quarterly 116, no. 4 (December 2001): 654–56. http://dx.doi.org/10.2307/798235.
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Williams-Hogan, Jane. "Servetus, Swedenborg and the Nature of God- by Andrew M. T. Dibb." Journal of Religious History 32, no. 3 (September 2008): 374–75. http://dx.doi.org/10.1111/j.1467-9809.2008.00674_4.x.
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Braga, F. A., F. J. D. Pardo, P. H. Miguez, A. Kehrle, J. R. V. Pimentel, C. C. Rocha, and E. H. Madureira. "13 USE OF A NEW INTRAVAGINAL DEVICE TO RELEASE PROGESTERONE IN FIXED-TIMED ARTIFICIAL INSEMINATION IN NELLORE COWS (BOS TAURUS INDICUS)." Reproduction, Fertility and Development 22, no. 1 (2010): 164. http://dx.doi.org/10.1071/rdv22n1ab13.
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Artificial insemination results can be improved using fixed-timed AI (FTAI). Currently, progesterone release devices, indispensable in FTAI procedures, such as DIB® (Schering-Plough, Kenilworth, NJ, USA), are made of silicone, a nonbiodegradable biocompatible polymer. Recently, biodegradable progesterone (P4)-releasing devices made of poly(3-hydroxy)butyrate-valerate copolymer (PHB-V) and poly-ϵ-caprolactona (PCL) have been developed. To investigate the efficiency on pregnancy rate of FTAI programs using a new intravaginal device made of PHB-V (Progestar®, Innovare, São Paulo, Brazil), 240 Nellore (Bos indicus) cows, between 3 and 8 years of age, were randomly assigned to 2 experiments. In experiment 1, new P4 devices DIB (control group, DIB1; n = 60) were compared with PHB-V (Progestar1; n = 76); in experiment 2, previously used DIB (DIB2; n = 52) and PHB-V (Progestar2; n = 52) devices were compared. All groups were treated with 2 mg of estradiol benzoate i.m. (Innovare) and received the intravaginal device according to group (Day 0). Together with P4 device withdrawal (Day 8) all animals received 300IU of eCG i.m. (Novormon®, Schering-Plough) and 150 μg i.m. of D-cloprostenol (Croniben®, Biogenesis-Bagó, Buenos Aires, Argentina). On Day 9, all cows were treated with 1 mg of estradiol benzoate and the FTAI was performed 30 h later. The data were submitted to ANOVA (PROC GLM of SAS, SAS Institute, Cary, NC, USA), separating as causes of variance the effect of treatment, postpartum period (PPP1-45 until 70 days and PPP2-71 until 90 days), body condition score (BCS4, BCS5, and BCS6 using a 1 to 9 scale), cyclicity (cycling and noncycling) and clean-up bulls (5 bulls nominated with numbers 1 to 5). Significant differences were considered to have P < 0.05. In experiment 1, interactions were not significant, there was no effect of treatment on FTAI (DIB1: 66.7% v. Progestar1: 65.8%) or breeding season pregnancy rates (BSPR; DIB1: 95.0% v. Progestar1: 94.7%) and no effect of other variables on FTAI pregnancy rates (FTAIPR) and BSPR. In experiment 2 there was no effect of treatment on FTAIPR (DIB2: 61.6% v. Progestar2: 55.8%) and BSPR (DIB2: 94.2% v. Progestar2: 88.5%). As ANOVA indicated a significant effect of clean-up bulls on BSPR, Tukey test was used to split it up. A bull of the Progestar2 group had lower performance (41.7%) causing the difference (albeit nonsignificant) on BSPR. This experiment showed that Progestar and DIB had the same efficiency on pregnancy rate and both treatments have the potential to produce FTAIPR >50% and BSPR >90%. Fapesp-Fundação de Amparo à Pesquisa do Estado de São Paulo. CNPq-Conselho Nacional de Desenvolvimento Científico e Tecnológico.
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Masschelein, Anneleen. "Ways of Seeing/Ways of Talking: Conversation and Collage in the Films of Mike Dibb." Biography 41, no. 2 (2018): 344–60. http://dx.doi.org/10.1353/bio.2018.0027.
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Kruhlova, O. A., and T. B. Ketova. "Evaluating the Prospects for the Development of Own Trademarks of Trade Enterprises." Business Inform 1, no. 516 (2021): 190–98. http://dx.doi.org/10.32983/2222-4459-2021-1-190-198.
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The article presents the results of the research on determining the prospects for the introduction and development of own trademarks (OTM) of the trade enterprise. The strategies of own trademarks of the trade enterprise are provided. The peculiarities of formation and implementation of dumping strategies, replacement of a competitor, brand expansion are specified. To determine the prospects for the introduction and development of own trademarks of the trade enterprise, a methodical approach is substantiated, which is formed using matrix methods, scorecard methods, and additive convolution. The developed methodical approach provides for the implementation of interrelated stages of evaluation of competitive positions of activity in relation to own trademarks compared to other types of current activities, favorable external environment and readiness of the trade enterprise for the implementation of this type of activity. To evaluate the competitive positions of the OTM-related activities in comparison with other types of current activities, the use of the Dibb –Symkin matrix and the modified BCG matrix is proposed; to assess the favorability of the external environment – PEST analysis; to assess the readiness of the trade enterprise for the introduction and development of its own trademarks – the method of scorecard according to the characteristics of organizational, technological and resource aspects of the trade enterprise’s activities regarding OTM. In order to ensure the validity of managerial decisions on optimizing the portfolio of own trademarks, a scientific-methodical approach to the ranking of assortment groups of goods that are part of own trademark is developed. The methodical basis of the developed approach is matrix methods (Dibb–Symkin matrix, modified BCG matrix), coefficient method, expert estimation method and additive convolution. The sequence of determining the competitiveness of the assortment of goods is presented, which involves grouping the assortment according to the indicators of quality, price, latitude of the assortment of goods compared to the range of products on the part of the trademark of competing enterprises and manufacturers.
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Ramírez-Tannus, M. C., N. L. J. Cox, L. Kaper, and A. de Koter. "Diffuse interstellar bands in the H II region M17." Astronomy & Astrophysics 620 (November 29, 2018): A52. http://dx.doi.org/10.1051/0004-6361/201833340.
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Context. Diffuse interstellar bands (DIBs) are broad absorption features measured in sightlines probing the diffuse interstellar medium. Although large carbon-bearing molecules have been proposed as the carriers producing DIBs, their identity remains unknown. DIBs make an important contribution to the extinction curve; the sightline to the young massive star-forming region M17 shows anomalous extinction in the sense that the total-to-selective extinction parameter (RV) differs significantly from the average Galactic value and may reach values RV > 4. Anomalous DIBs have been reported in the sightline towards Herschel 36 (RV = 5.5), in the massive star-forming region M8. Higher values of RV have been associated with a relatively higher fraction of large dust grains in the line of sight. Aims. Given the high RV values, we investigate whether the DIBs in sightlines towards young OB stars in M17 show a peculiar behaviour. Methods. We measure the properties of the most prominent DIBs in M17 and study these as a function of E(B–V) and RV. We also analyse the gaseous and dust components contributing to the interstellar extinction. Results. The DIB strengths in M17 concur with the observed relations between DIB equivalent width and reddening E(B–V) in Galactic sightlines. For several DIBs we discover a linear relation between the normalised DIB strength EW/AV and RV−1. These trends suggest two groups of DIBs: (i) a group of ten moderately strong DIBs that show a sensitivity to changes in RV that is modest and proportional to DIB strength, and (ii) a group of four very strong DIBs that react sensitively and to a similar degree to changes in RV, but in a way that does not appear to depend on DIB strength. Conclusions. DIB behaviour as a function of reddening is not peculiar in sightlines to M17. Also, we do not detect anomalous DIB profiles like those seen in Herschel 36. DIBs are stronger, per unit visual extinction, in sightlines characterised by a lower value of RV, i.e. those sightlines that contain a relatively large fraction of small dust particles. New relations between extinction normalised DIB strengths, EW/AV, and RV support the idea that DIB carriers and interstellar dust are intimately connected. Furthermore, given the distinct behaviour of two groups of DIBs, different types of carriers do not necessarily relate to the dust grains in a similar way.
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Petrova, Anastasiya Valerevna. "Matrix methods of product range analysis and their comparative characteristics." KANT 40, no. 3 (March 2021): 62–67. http://dx.doi.org/10.24923/2222-243x.2021-40.12.
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Implementing the key functions, any company is faced with issues related to the formation and analysis of the range of goods, products, services. Regardless of the field of activity, enterprises need to analyze each product line separately in order to make timely adjustments to the product range policy, which directly affects the economic efficiency of the enterprise as a whole. The purpose of the study is to reveal the content of matrix methods of assortment analysis. The article deals with the concepts of "assortment", "product assortment", their meaning and impact on the company's activities; matrix methods: BKG matrix; Dibb-Simkin matrix; Markon matrix. The scientific novelty lies in the author's interpretation of the comparative characteristics of these methods, summarized in a tabular form, allowing enterprises to choose the optimal method when analyzing assortment positions in real business conditions.
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Fan, Haoyu, Madison Schwartz, Amin Farhang, Nick L. J. Cox, Pascale Ehrenfreund, Ana Monreal-Ibero, Bernard H. Foing, et al. "Families and clusters of diffuse interstellar bands: a data-driven correlation analysis." Monthly Notices of the Royal Astronomical Society 510, no. 3 (December 16, 2021): 3546–60. http://dx.doi.org/10.1093/mnras/stab3651.
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ABSTRACT More than 500 diffuse interstellar bands (DIBs) have been observed in astronomical spectra, and their signatures and correlations in different environments have been studied over the past decades to reveal clues about the nature of the carriers. We compare the equivalent widths of the DIBs, normalized to the amount of reddening, EB-V, to search for anticorrelated DIB pairs using a data sample containing 54 DIBs measured in 25 sightlines. This data sample covers most of the strong and commonly detected DIBs in the optical region, and the sightlines probe a variety of interstellar medium conditions. We find that 12.9 per cent of the DIB pairs are anticorrelated, and the lowest Pearson correlation coefficient is rnorm ∼ −0.7. We revisit correlation-based DIB families and are able to reproduce the assignments of such families for the well-studied DIBs by applying hierarchical agglomerative and k-means clustering algorithms. We visualize the dissimilarities between DIBs, represented by 1 − rnorm, using multidimensional scaling (MDS). With this representation, we find that the DIBs form a rather continuous sequence, which implies that some properties of the DIB carriers are changing gradually following this sequence. We also find that at that least two factors are needed to properly explain the dissimilarities between DIBs. While the first factor may be interpreted as related to the ionization properties of the DIB carriers, a physical interpretation of the second factor is less clear and may be related to how DIB carriers interact with surrounding interstellar material.
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Gnaciński, P., and J. Krełowski. "DIBs Broadening with Increased Abundance of Vibrationally Excited H2 Molecules." Proceedings of the International Astronomical Union 9, S297 (May 2013): 125–27. http://dx.doi.org/10.1017/s174392131301572x.
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AbstractThe analysis of DIB profiles was used in various attempts to discover the DIBs carriers. The broadening of the 6196 Å DIB with increasing C2 rotational temperature was reported by Kaźmierczak et al. (2009). We present the broadening of the 4763, 5780 and 6614 Å DIBs connected with higher abundance of vibrationally excited hydrogen molecule. The DIBs broadening is also correlated with increasing H2 rotational temperature on the ν=2 vibrational level. The broadening may be caused by growing population of higher rotational levels in the DIB carrier. Some DIBs, like 4964 Å, do not show any width changes with higher population of vibrationally excited H2.
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Perkuhn, Josie-Marie. "Paul Dibb: How the geopolitical partnership between China and Russia threatens the West. Canberra: ASPI, November 2019." SIRIUS – Zeitschrift für Strategische Analysen 4, no. 1 (April 1, 2020): 92–94. http://dx.doi.org/10.1515/sirius-2020-1011.
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Cha, V. D. "America's Asian Alliances. Robert D. Blackwill and Paul Dibb (eds), Cambridge, MA: MIT Press, 2000. 160pp, pound12.95." Survival 43, no. 4 (December 1, 2001): 164–65. http://dx.doi.org/10.1093/survival/43.4.164.
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Hamano, Satoshi, Naoto Kobayashi, Hideyo Kawakita, Keiichi Takenaka, Yuji Ikeda, Noriyuki Matsunaga, Sohei Kondo, et al. "Survey of Near-infrared Diffuse Interstellar Bands in Y and J Bands. I. Newly Identified Bands." Astrophysical Journal Supplement Series 262, no. 1 (August 17, 2022): 2. http://dx.doi.org/10.3847/1538-4365/ac7567.
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Abstract We searched for diffuse interstellar bands (DIBs) in the 0.91 < λ < 1.33 μm region by analyzing the near-infrared (NIR) high-resolution (R = 20,000 and 28,000) spectra of 31 reddened early-type stars (0.04 < E(B − V) < 4.58) and an unreddened reference star. The spectra were collected using the WINERED spectrograph, which was mounted on the 1.3 m Araki telescope at Koyama Astronomical Observatory, Japan, in 2012–2016, and on the 3.58 m New Technology Telescope at La Silla Observatory, Chile, in 2017–2018. We detected 54 DIBs—25 of which are newly detected by this study—and eight DIB candidates. Using this updated list, the DIB distributions over a wide wavelength range, from optical to NIR, are investigated. The FWHM values of the NIR DIBs are found to be narrower than those of the optical DIBs, on average, which suggests that the DIBs at longer wavelengths tend to be caused by larger molecules. Assuming that the larger carriers are responsible for the DIBs at longer wavelengths, and have larger oscillator strengths, we found that the total column densities of the DIB carriers tend to decrease with increasing DIB wavelength. The candidate molecules and ions for the NIR DIBs are also discussed.
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Welty, D. E. "Diffuse Interstellar Bands: How are they related to known Gas-Phase Constituents of the ISM?" Proceedings of the International Astronomical Union 9, S297 (May 2013): 153–62. http://dx.doi.org/10.1017/s1743921313015792.
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AbstractIn this brief review of recent work relating the DIBs to other gas-phase constituents of the ISM, we explore correlations between DIB equivalent widths and the column densities of various atomic and molecular species, drawn from a large database constructed for that purpose. The tightness and slopes of the correlations can provide information on how the DIBs might be related to those species (physically, chemically, spatially) and on various properties of the DIB carriers. Deviations from the mean relationships can reveal dependences of DIB strengths on other parameters, regional variations in DIB behavior, and individual sight lines where unusual environmental conditions affect the DIBs. Variations in DIB profiles (e.g., wings, substructure) and relative strengths may be related to differences in physical conditions inferred from atomic and/or molecular absorption lines.
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Barlow, Nathan E., Halim Kusumaatmaja, Ali Salehi-Reyhani, Nick Brooks, Laura M. C. Barter, Anthony J. Flemming, and Oscar Ces. "Measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers." Journal of The Royal Society Interface 15, no. 148 (November 2018): 20180610. http://dx.doi.org/10.1098/rsif.2018.0610.
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For the past decade, droplet interface bilayers (DIBs) have had an increased prevalence in biomolecular and biophysical literature. However, much of the underlying physics of these platforms is poorly characterized. To further our understanding of these structures, lipid membrane tension on DIB membranes is measured by analysing the equilibrium shape of asymmetric DIBs. To this end, the morphology of DIBs is explored for the first time using confocal laser scanning fluorescence microscopy. The experimental results confirm that, in accordance with theory, the bilayer interface of a volume-asymmetric DIB is curved towards the smaller droplet and a lipid-asymmetric DIB is curved towards the droplet with the higher monolayer surface tension. Moreover, the DIB shape can be exploited to measure complex bilayer surface energies. In this study, the bilayer surface energy of DIBs composed of lipid mixtures of phosphatidylgylcerol (PG) and phosphatidylcholine are shown to increase linearly with PG concentrations up to 25%. The assumption that DIB bilayer area can be geometrically approximated as a spherical cap base is also tested, and it is discovered that the bilayer curvature is negligible for most practical symmetric or asymmetric DIB systems with respect to bilayer area.
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Marziali, Elsa, Heather Munroe-Blum, and Paul Links. "Severity as a Diagnostic Dimension of Borderline Personality Disorder." Canadian Journal of Psychiatry 39, no. 9 (November 1994): 540–44. http://dx.doi.org/10.1177/070674379403900905.
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The purpose of this study was to identify diagnostic and severity subgroups within a cohort of patients with borderline personality disorder (BPD). Of 171 patients clinically diagnosed with BPD, 132 were Diagnostic Interview for Borderlines (DIB) positive. Through a process of random selection, 41 of the DIB positive subjects were also interviewed with the revised version of the DIB (DIBR) and approximately one half with two semi-structured research interviews, the Schedule for Affective Disorders (SADS) and the Personality Disorder Examination (PDE). All subjects completed four self-report measures of problematic behaviours, symptoms and social adaptation. The analyses included examination of: 1. the correspondence of the BPD diagnosis across the DIB, the DIBR and the PDE; 2. the association between DIBR scoring levels and scores on measures of symptoms and behavioural status; and 3. the co-occurrence of BPD with Axis I and other Axis II disorders. Correlations and analyses of variance between both the DIB and DIBR scoring levels and the scores on the four symptom and behavioural measures showed that the scoring levels (DIB 7 to 10; DIBR 8 to 10) could be used to distinguish three subgroups of BPD. The three groups differed in terms of concordance for BPD with the PDE and in terms of patterns of overlap with DSM-III-R, Axis I and other Axis II disorders. This study shows that BPD subgroups can be located on a continuum of symptomatic and behavioural severity and that each subgroup has a specific pattern of overlap with Axis I and other Axis II disorders.
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Foing, B. H. "Exploring the Limits to Observational Diffuse Interstellar Band Studies." Proceedings of the International Astronomical Union 9, S297 (May 2013): 51–57. http://dx.doi.org/10.1017/s1743921313015561.
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AbstractThe status of DIB research (Herbig 1995) has strongly advanced since the DIB conference in Boulder in 1994. In the same year we reported the discovery of two near IR diffuse bands coincident with C60+, that was confirmed in subsequent years. Since then a number of DIB observational studies have been published such as DIB surveys, measurements of DIB families, correlations and environment dependences as well as DIBs in extra-galactic sources. Resolved substructures were measured and compared to predicted rotational contours of large molecules. Polarisation studies provided constraints on possible carrier molecules and upper limits. DIBs carriers have been linked with several classes of organic molecules observed in the interstellar medium, in particular to the UIR bands (assigned to PAHs), the Extended Red Emission (ERE) or the recently detected Anomalous Microwave Emission (AME, assigned to spinning dust). In particular fullerenes and PAHs have been proposed to explain some DIBs and specific molecules were searched for in DIB spectra. DIB carriers could be present in various dehydrogenation and ionization states. Experiments in the laboratory and in space contribute to our understanding of the photo-stability of possible DIB carriers. In summary, the status of DIB research in the last 20 years has strongly advanced. We review DIB observational results and their interpretation and introduce the relevant plenary discussion.
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Rouillé, G., C. Jäger, F. Huisken, and T. Henning. "Polyynyl-Substituted PAH Molecules and DIB Carriers." Proceedings of the International Astronomical Union 9, S297 (May 2013): 276–80. http://dx.doi.org/10.1017/s1743921313015986.
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AbstractPolycyclic aromatic hydrocarbon (PAH) molecules have been long considered promising candidates for the carriers of the diffuse interstellar bands (DIBs). The PAH-DIB hypothesis, however, raises two major issues. First, the number of interstellar PAH species is potentially orders of magnitude larger than the number of DIBs. Second, the absorption spectrum of a PAH is in general dominated by bands found at UV wavelengths while, conversely, DIBs are absent from the UV wavelength domain and arise at visible and near IR wavelengths. These issues do not necessarily weaken the PAH-DIB hypothesis and can actually allow us to refine it. In that context, we analyze the UV/vis absorption spectra of PAH molecules isolated in Ne matrices and propose that polyynyl-substituted PAHs, or similar species, are valid candidates for the carriers of the DIBs. Finally, a possible lifecycle for DIB-carrying PAHs is presented.
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Snow, T. P. "Diffuse Interstellar Bands: Past and Present." Proceedings of the International Astronomical Union 9, S297 (May 2013): 3–12. http://dx.doi.org/10.1017/s1743921313015512.
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AbstractThe diffuse interstellar bands (DIBs) have come to the fore as an important mystery. This paper presents the history of DIB discovery and research; their importance; a summary of their properties; constraints on proposed identifications; a survey of DIB papers (including graduate student's theses); and a web site that lists DIBs paper from 1922 to 2011 (to be extended to the present).
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Li, Kaijun, Aigen Li, and F. Y. Xiang. "Probing the missing link between the diffuse interstellar bands and the total-to-selective extinction ratio $R_V\,\!-\!$ I. Extinction versus reddening." Monthly Notices of the Royal Astronomical Society 489, no. 1 (August 12, 2019): 708–13. http://dx.doi.org/10.1093/mnras/stz2103.
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ABSTRACT The carriers of the still (mostly) unidentified diffuse interstellar bands (DIBs) have been a long-standing mystery ever since their first discovery exactly 100 yr ago. In recent years, the ubiquitous detection of a large number of DIBs in a wide range of Galactic and extragalactic environments has led to renewed interest in connecting the occurrence and properties of DIBs to the physical and chemical conditions of the interstellar clouds, with particular attention paid to whether the DIB strength is related to the shape of the interstellar extinction curve. To shed light on the nature and origin of the DIB carriers, we investigate the relation between the DIB strength and RV, the total-to-selective extinction ratio, which characterizes how the extinction varies with wavelength (i.e. the shape of the extinction curve). We find that the DIB strength and RV are not related if we represent the strength of a DIB by its reddening-normalized equivalent width (EW), in contrast to the earlier finding of an anticorrelation in which the DIB strength is measured by the extinction-normalized EW. This raises a fundamental question about the appropriate normalization for the DIB EW. We argue that the hydrogen column density is a more appropriate normalization than extinction and reddening.
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Krełowski, J. "Diffuse Interstellar Bands: Families and Correlations." Proceedings of the International Astronomical Union 9, S297 (May 2013): 23–33. http://dx.doi.org/10.1017/s1743921313015536.
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AbstractThe term “families of diffuse bands” (DIBs) appeared in 1986/87 when my collaborators: Gordon A.H. Walker, Bengt E. Westerlund and I found that the strength ratio of the major DIBs 5780 and 5797 is heavily variable. We proved that at the same E(B-V) the DIB intensities may vary by as much as a factor of three or more. A similar result was published by Karl Josafatsson and Ted Snow soon after. A decade later, we proved (with Chris Sneden) that certain DIB strength ratios seem to be related to intensities of the known features of simple molecular species; this led to the introduction of the so called σ and ζ type interstellar clouds. The former are characterized by very weak molecular features (but broad DIBs – very strong) while the latter by rather strong bands of simple radicals and weak broad DIBs. Currently we face a bunch of questions: are the DIB intensities related to those of certain molecular species, e.g. C2 as suggested by Lew Hobbs' and Ted Snow's group? Do the DIB profiles, found to be complex by Peter Sarre, depend on e.g. the rotational temperatures of simple, linear carbon species? Do the DIB profiles depend on the irradiation of interstellar clouds by nearby stars? The relative DIB strengths as well as those of the simple radicals seem to be related to the shapes of interstellar extinction curves. We thus face three players in the interstellar translucent clouds: dust particles, simple radicals and the DIB carriers. Apparently, their mutual relations depend on local physical parameters of intervening clouds; these relations are not clear yet.
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Kennedy, Ann-Marie, Joya A. Kemper, and Andrew Grant Parsons. "Upstream social marketing strategy." Journal of Social Marketing 8, no. 3 (July 9, 2018): 258–79. http://dx.doi.org/10.1108/jsocm-03-2017-0016.
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Purpose This paper aims to provide guidelines for upstream social marketing strategy on to whom, how and when social marketers can undertake upstream social marketing. Design/methodology/approach This article is a conceptual piece using academic literature to justify and conceptualise an approach to communicating with and influencing upstream actors. Findings Specifically, it looks at the characteristics of policymakers targeted, then targeting methods, with a special focus on the use of media advocacy. Finally, a process of government decision-making is presented to explain message timing and content. Practical implications Specific criteria to judge time of decision-making and implementation guidelines are provided for social marketers. Originality/value In the case of complex social problems, such as obesity and environmental degradation, structural change is needed to provide people with the ability to change (Andreasen, 2006). Strategic social marketing has identified upstream social marketing as a method to influence structural change through policymakers (French and Gordon, 2015); however, literature in the area tends to be descriptive and there are no clear guidelines to its implementation (Dibb, 2014). This article seeks to provide those guidelines.
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Monreal-Ibero, A., P. M. Weilbacher, and M. Wendt. "Diffuse interstellar bands λ5780 and λ5797 in the Antennae Galaxy as seen by MUSE." Astronomy & Astrophysics 615 (July 2018): A33. http://dx.doi.org/10.1051/0004-6361/201732178.
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Context. Diffuse interstellar bands (DIBs) are faint spectral absorption features of unknown origin. Research on DIBs beyond the Local Group is very limited and will surely blossom in the era of the Extremely Large Telescopes. However, we can already start paving the way. One possibility that needs to be explored is the use of high-sensitivity integral field spectrographs. Aims. Our goals are twofold. First, we aim to derive reliable mapping of at least one DIB in a galaxy outside the Local Group. Second, we want to explore the relation between DIBs and other properties of the interstellar medium (ISM) in the galaxy. Methods. We use Multi Unit Spectroscopic Explorer (MUSE) data for the Antennae Galaxy, the closest major galaxy merger. High signal-to-noise spectra were created by co-adding the signal of many spatial elements with the Voronoi binning technique. The emission of the underlying stellar population was modelled and substracted with the STARLIGHT spectral synthesis code. Flux and equivalent width of the features of interest were measured by means of fitting to Gaussian functions. Results. To our knowledge, we have derived the first maps for the DIBs at λ5780 and λ5797 in galaxies outside the Local Group. The strongest of the two DIBs (at λ5780) was detected in an area of ~0.6□′, corresponding to a linear scale of ~25 kpc2. This region was sampled using >200 out of ~1200 independent lines of sight. The DIB λ5797 was detected in >100 independent lines of sight. Both DIBs are associated with a region of high emission in the H I 21 cm line, implying a connection between atomic gas and DIBs, as the correlations in the Milky Way also suggest. Conversely, there is mild spatial association between the two DIBs and the molecular gas, in agreement with results for our Galaxy that indicate a lack of correlation between DIBs and molecular gas. The overall structures for the DIB strength distribution and extinction are comparable. Within the system, the λ5780 DIB clearly correlates with the extinction, and both DIBs follow the relationship between equivalent width and reddening when data for several galaxies are considered. This relationship is tighter when comparing only with galaxies with metallicities close to solar. Unidentified infrared emission bands (UIBs, likely caused by polycyclic aromatic hydrocarbons PAHs) and the λ5780 and λ5797 DIBs show similar but not identical spatial distributions. We attribute the differences to extinction effects without necessarily implying a radically different nature of the respective carriers. Conclusions. The results illustrate the enormous potential of integral field spectrographs for extragalactic DIB research.
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Smith, K. T., M. A. Cordiner, C. J. Evans, N. L. J. Cox, and P. J. Sarre. "Diffuse Interstellar Bands in M33." Proceedings of the International Astronomical Union 9, S297 (May 2013): 74–78. http://dx.doi.org/10.1017/s1743921313015603.
Full textAbstract:
AbstractWe present the first sample of diffuse interstellar bands (DIBs) in the nearby galaxy M33. Studying DIBs in other galaxies allows the behaviour of the carriers to be examined under interstellar conditions which can be quite different from those of the Milky Way, and to determine which DIB properties can be used as reliable probes of extragalactic interstellar media. Multi-object spectroscopy of 43 stars in M33 has been performed using Keck/DEIMOS. The stellar spectral types were determined and combined with literature photometry to determine the M33 reddenings E(B-V)M33. Equivalent widths or upper limits have been measured for the λ5780 DIB towards each star. DIBs were detected towards 20 stars, demonstrating that their carriers are abundant in M33. The relationship with reddening is found to be at the upper end of the range observed in the Milky Way. The line of sight towards one star has an unusually strong ratio of DIB equivalent width to E(B-V)M33, and a total of seven DIBs were detected towards this star.
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Smith, Fraser M., Tina A. Harriott, Daniel Majaess, Lou Massa, and Chérif F. Matta. "Establishing new diffuse interstellar band correlations to identify common carriers." Monthly Notices of the Royal Astronomical Society 507, no. 4 (August 27, 2021): 5236–45. http://dx.doi.org/10.1093/mnras/stab2444.
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ABSTRACT Observations from the Apache Point Observatory Catalog of Optical Diffuse Interstellar Bands (DIBs) were analysed to establish highly correlated pairs in terms of their equivalent widths (EWs) (r > 0.95), which importantly facilitate the identification of common carriers. A total of 154 846 possible DIB pairs were originally examined, yet only those with a sufficient number of sightlines (n > 9) that included EW uncertainties were subsequently investigated. The highest correlations for the resulting 56 893 DIB pairs are 6284.05–6203.58 Å (r = 0.990 ± 0.001), 6203.58–5780.64 Å (r = 0.986 ± 0.001), 6993.12–6269.89 Å (r = 0.984 ± 0.001), 6843.76–6792.51 Å (r = 0.984 ± 0.005), 6203.58–5487.64 Å (r = 0.983 ± 0.002), and 5061.50–4969.12 Å (r = 0.983 ± 0.009). The bands 5363.77, 5780.64, 6203.58, and 6284.05 Å appear most frequently. Novel relations linked to those DIBs and others warrant further research, in particular those pairs that involve one or both DIBs with low EWs (e.g. 5609.82, 6269.89, 6993.12, and 7224.16 Å). Numerous DIBs correlated with the prominent 4429.33 Å band were also discovered. The intriguing proposal of anionic hydrogen clusters as possible DIB carriers is also discussed.
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Sonnentrucker, P. "Modern DIB Surveys and DIB Environmental Behavior." Proceedings of the International Astronomical Union 9, S297 (May 2013): 13–22. http://dx.doi.org/10.1017/s1743921313015524.
Full textAbstract:
AbstractSince the discovery of the Diffuse Interstellar Bands (DIBs) in the early 1920s, numerous research groups have taken on the task to obtain as complete a census of the DIBs as observationally possible in order to unravel characteristics that would allow the community to tie the DIB carriers to known species. Here, I will briefly review the efforts and progress that were made for the past two decades in producing new, deeper, and more complete DIB surveys. In particular, I will review the important role that these modern surveys are playing in revealing main observational characteristics of the DIBs and their dependence on the local physical conditions in the Galactic Interstellar Medium.
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Omont, A., H. F. Bettinger, and C. Tönshoff. "Polyacenes and diffuse interstellar bands." Astronomy & Astrophysics 625 (May 2019): A41. http://dx.doi.org/10.1051/0004-6361/201834953.
Full textAbstract:
The identification of the carriers of the diffuse interstellar bands (DIBs) remains to be established, with the exception of five bands attributed to C60+, although it is generally agreed that DIB carriers should be large carbon-based molecules (with ~10–100 atoms) in the gas phase, such as polycyclic aromatic hydrocarbons (PAHs), long carbon chains or fullerenes. The aim of this paper is to investigate more specific possible carriers among PAHs, namely elongated molecules, which could explain a correlation between the DIB wavelength and the apparent UV resilience of their carriers. More specifically, we address the case of polyacenes, C4N+2H2N+4, with N ~ 10–18 fused rectilinear aligned hexagons. Polyacenes are attractive DIB carrier candidates because their high symmetry and large linear size allow them to form regular series of bands in the visible range with strengths larger than most other PAHs, as confirmed by recent laboratory results up to undecacene (C46H26). Those with very strong bands in the DIB spectral domain are just at the limit of stability against UV photodissociation. They are part of the prominent PAH family of interstellar carbon compounds, meaning that only ~10−5 of the total PAH abundance is enough to account for a medium-strength DIB. After summarizing the limited current knowledge about the complex properties of polyacenes and recent laboratory results, the likelihood that they might meet the criteria for being carriers of some DIBs is addressed by reviewing the following properties: wavelength and strength of their series of visible bands; interstellar stability and abundances, charge state and hydrogenation; and DIB rotation profiles. No definite inconsistency has been identified that precludes polyacenes from being the carriers of some DIBs with medium or weak strength, including the so-called C2 DIBs. But, despite their many interesting properties, additional experimental data about long acenes and their visible bands are needed to make robust conclusions.
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Salama, F., and P. Ehrenfreund. "A Critical Review of PAHs as DIB Carriers - Progress and Open Questions." Proceedings of the International Astronomical Union 9, S297 (May 2013): 364–69. http://dx.doi.org/10.1017/s174392131301613x.
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AbstractPAHs are among the most commonly proposed and popular candidates for DIB carriers. We present a critical assessment of the PAH-DIB model in view of the progress and the advances that have recently been achieved through a series of complementary studies involving astronomical observations of DIBs, laboratory simulation of interstellar analogs for PAHs (neutrals and ions), space exposure experiments of PAHs, theoretical calculations of PAH spectra and the modeling of diffuse and translucent interstellar clouds. What have we learned from these complementary studies? What are the constraints that can now be derived for the PAHs as DIB carriers? What are the strengths and the weaknesses of the PAH model to account for the DIBs?
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Aydin, Hatice S., N. Hande Kutbay, Zeynep Yalman, and Cemil Yavuz. "User involvement in context of innovation: user innovation." International Journal of Innovative Research in Education 2, no. 2 (April 5, 2016): 68. http://dx.doi.org/10.18844/ijire.v2i2.353.
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“User” , as subject of studies after World War II, were frequently studied in 1980s in the field of Economics and Management as well. While in particular it was held in the Consumer Behaviour context, it was divided into subheadings according to the process it was included (such as purchase decision; Mittal, 1989; Slama and Tashchian, 1985; Smith and Bristor, 1994; cited in Michaelidou and Dibb, 2008) and each subheading had evaluated in its way. But there is a conflict about the involvement process in this context because the notion of consumer describes the subject as passive. In case, the main aim of this paper is to define “user” as an active agent by presupposition of user’s potentiality. In this context, the user involvement is studied in terms of innovation which is the intersection of management and new product development. The research is based on literature review and seeking for an answer of the reasons and fundamentals of user involvement in innovation process. The condition of user in terms of involvement is discussed in the light of the answers that we deduce from the literature review.Keywords: User involvement, innovation, user innovation.
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Omont, A., and H. F. Bettinger. "Correlation between UV resilience and wavelength of narrow diffuse interstellar bands." Astronomy & Astrophysics 637 (May 2020): A74. http://dx.doi.org/10.1051/0004-6361/201937071.
Full textAbstract:
Carriers of diffuse interstellar bands (DIBs) still need to be identified. In a recent paper, we reported a correlation between the DIB wavelength and the apparent UV resilience (or boost) of their carriers. We proposed that this might be an indication of the important role of conjugated elongated molecules among the DIB carriers. The aim of this paper is to further understand the origin of this correlation. The analysis of 509 optical DIBs on the lines of sight of HD 183143 and/or HD 204827 reported in the literature shows that this correlation mainly implies the 386 narrow DIBs with a band width <1.1 Å, which include most of the identified DIBs of the C2 and ζ families, while the majority of the 123 broader DIBs, including the identified σ DIBs, do not display such a correlation. We present a possible origin of this correlation from very strong bands of large conjugated elongated molecules, such as carbon chains, polyacenes, or other catacondensed polycyclic aromatic hydrocarbons. The total amount of carbon contained in all the carriers of these narrow DIBs is a very small fraction of the interstellar carbon if their oscillator strengths are ≥1. The amount of carbon locked in the carriers of the broader DIBs is higher, especially if their oscillator strengths are significantly weaker.
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Lawton, Brandon, Christopher W. Churchill, Brian A. York, Sara L. Ellison, Theodore P. Snow, Rachel A. Johnson, Sean G. Ryan, and Chris R. Benn. "Evidence of Magellanic-like moderate redshift H i-rich galaxies." Proceedings of the International Astronomical Union 4, S256 (July 2008): 479–85. http://dx.doi.org/10.1017/s1743921308028895.
Full textAbstract:
AbstractWe present equivalent width measurements and limits of six diffuse interstellar bands (DIBs, λ 4428, λ 5705, λ 5780, λ 5797, λ 6284, and λ 6613) in seven damped Lyα absorbers (DLAs) over the redshift range 0.091 ≤ z ≤ 0.524, sampling 20.3 ≤ log N(Hi) ≤ 21.7. Based upon the Galactic DIB–N(H i) relation, the λ 6284 DIB equivalent width upper limits in four of the seven DLAs are a factor of 4–10 times below the λ 6284 DIB equivalent widths observed in the Galaxy, but are not inconsistent with those present in the Magellanic Clouds. Assuming the Galactic DIB–E(B − V) relation, we determine reddening upper limits for the DLAs in our sample. Based upon the E(B − V) limits, the gas-to-dust ratios, N(H i)/E(B − V), of the four aforementioned DLAs are at least ~5 times higher than that of the Galactic ISM and are more consistent with the Large Magellanic Cloud. The ratios of two other DLAs are at least a factor of a few times higher. The best constraints on reddening derive from the upper limits for the λ 5780 and λ 6284 DIBs, which yield E(B − V) ≤ 0.08 mag for four of the seven DLAs and are more consistent with the Magellanic Clouds rather than the Galaxy. Our results suggest that, in DLAs, quantities related to dust, such as reddening and metallicity, appear to have a greater impact on DIB strengths than does H i gas abundance. The molecules responsible for the DIBs in DLA selected sightlines are underabundant relative to sightlines in the Galaxy of similarly high N(H i). Using DIBs to study the ISM of DLAs provide evidence that at least some population of DLAs are more Magellanic-like than Galactic-like.
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Clayton, G. C. "DIBs, Interstellar Dust, and Extinction." Proceedings of the International Astronomical Union 9, S297 (May 2013): 147–52. http://dx.doi.org/10.1017/s1743921313015780.
Full textAbstract:
AbstractThe relationship between DIBs and dust is still unknown. The correlation between reddening and DIB strength means that the DIBs are mixed in with the dust and gas in interstellar clouds. The DIBs are relatively stronger in the diffuse interstellar medium than in dense clouds. There is only a weak correlation between the DIBs and the UV extinction parameters including the 2175 Å bump strength and the far-UV rise. In addition, the bump dust grains are sometimes polarized, while the DIBs are not. However, observations of DIBs in the SMC show that when the 2175 Å bump is weak or missing so are the DIBs. Two of the four sightlines that deviate strongly from the CCM UV extinction in the Galaxy show weak DIBs.
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Cordiner, M. A. "Extragalactic Diffuse Interstellar Bands: A Universal Problem." Proceedings of the International Astronomical Union 9, S297 (May 2013): 41–50. http://dx.doi.org/10.1017/s174392131301555x.
Full textAbstract:
AbstractThe first extragalactic diffuse interstellar band (DIB) detections were of λ4430 in the Large and Small Magellanic Clouds (LMC and SMC) in the 1960s and 70s. Driven mainly by the increased sensitivity afforded by 8-10 m-class telescopes, the last 13 years have witnessed an explosion of DIB discoveries throughout the nearby and distant universe. This review focuses on the history of extragalactic DIB studies, including some of the important results that have come out of this field, and looks to the future for what can be learned about DIBs in external galaxies with the next generation of large telescopes. So far, DIBs have been observed in the Magellanic Clouds, starburst galaxies, DLAs, and nearby (≤30 Mpc distant) spiral galaxies, and are found to be ubiquitous in the diffuse interstellar medium (ISM) of extragalactic environments wherever dust is present. Important results include the finding that DIB carriers are significantly more closely related to dust than to neutral hydrogen, and that the λ6283 DIB tends to be anomalously weak in low-metallicity sightlines.
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Weselak, T. "The relation between 5780 and 5797 diffuse interstellar bands, CH/CH+ molecules, and atomic or molecular hydrogen." Astronomy & Astrophysics 625 (May 2019): A55. http://dx.doi.org/10.1051/0004-6361/201834576.
Full textAbstract:
Correlations between column densities of neutral and molecular hydrogen and strengths of major 5780 and 5797 Å diffuse interstellar bands (DIBs) based on spectra of 66 OB stars were analyzed. We confirm that the 5797 Å DIB is more tightly correlated with column density of molecular hydrogen while the 5780 DIB – with that of atomic hydrogen. This leads to a reasonably tight relation between the molecular fraction of H2 and equivalent width ratio of the 5797 and 5780 major diffuse bands with correlation coefficient equal to 0.77 ± 0.05. Column densities of CH and CH+ molecules were used to analyze correlations between abundances of CH/CH+ molecules and strengths of the major 5780 and 5797 DIBs. The 5780 DIB is better correlated with the column density of methydyline cation than the 5797 DIB. A relation with correlation coefficient equal to 0.95 ± 0.02 based on precise column densities, between column densities of CH and H2 molecules, is also presented; in other words, the column densitiy ratio in the case of H2 and CH molecules in the ISM is equal to (2.01 ± 0.09) × 107.
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Bondar, A., and J. Krełowski. "A Possible New Sequence of DIBs." Proceedings of the International Astronomical Union 9, S297 (May 2013): 135–37. http://dx.doi.org/10.1017/s1743921313015755.
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AbstractOne of the key factors in explaining nature of DIB carriers is to find regularities in their spectrum. Such a regular set of DIBs exists within interval λλ 6770–6865 Å. A possible new sequence of weak DIBs between λλ 5910–5990 Å is presented here. The new sequence is clearly visible in high resolution spectra (R ≳ 100,000) of some hot, reddened stars. Wavenumbers' differences, or spacings, between the most strong bands have values ~35, ~40 cm−1, which are very similar to those, found for DIBs near 6800 Å.
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Chen, H. Ch, R. Lallement, L. Puspitarini, P. Bonifacio, C. Babusiaux, and V. Hill. "Automated Extraction of DIBs from Cool Star Spectra." Proceedings of the International Astronomical Union 9, S297 (May 2013): 110–12. http://dx.doi.org/10.1017/s1743921313015688.
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AbstractWe have developed a method allowing to extract DIBs from cool star spectra, based on combinations of stellar synthetic, telluric transmission (when necessary), and DIB profile models. It is applicable when the star temperature, surface gravity and metallicity have been previously estimated. Such a method aims at extracting extensive data from stellar spectroscopic surveys such as the Gaia-ESO Survey in progress at the VLT. The method has been applied to several strong DIBs detected towards stars from various programs and located at various distances from the solar neighborhood to the Galactic Bulge. Here we illustrate the extraction of the 8620 Å DIB, and compare its strength to the one of the 6284 Å band, both for nearby and bulge stars.
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Carvalho, Adolfo S., and Lynne A. Hillenbrand. "Measuring Optical Extinction toward Young Stellar Objects Using Diffuse Interstellar Bands." Astrophysical Journal 940, no. 2 (December 1, 2022): 156. http://dx.doi.org/10.3847/1538-4357/ac9d8e.
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Abstract Line-of-sight extinction estimates of well-studied young T Tauri and Herbig Ae/Be stars are based on many different measurements and analysis methods. This has resulted in wide scatter among the published A V values for the same star. In this work, we discuss the challenges in measuring extinction to actively accreting and especially outbursting young stellar objects (YSOs). We then explore a method not previously applied to young stars utilizing diffuse interstellar bands (DIBs). In early-type stars, narrow correlations exist between the DIB equivalent widths and the column density of interstellar material, and therefore the line-of-sight extinction. Here, we measure the equivalent widths of the 5780 and 6614 Å DIB features in a sample of actively accreting YSOs, and apply a DIB-reddening calibration to estimate reddening and subsequently extinction. Our calibration is newly derived from a composite of available literature data and fully accounts for the scatter in these measurements. We also compare the DIBs-inferred optical line-of-sight extinction values with previous extinction estimates for our sample stars.
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Geballe, T. R. "New Infrared Diffuse Interstellar Bands in the Galactic Center and Elsewhere." Proceedings of the International Astronomical Union 9, S297 (May 2013): 64–67. http://dx.doi.org/10.1017/s1743921313015585.
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AbstractThis paper updates the recent discovery of over a dozen new diffuse interstellar bands (DIBs), first in H-band spectra of stars in the Galactic center (GC) and toward stars in the Cygnus OB2 Association. The H-band DIBs, which currently number 15, are the longest wavelength DIBs reported to date and are the first found on sightlines toward the Galactic center. K-band (2.0-2.5 μm) spectra of the GC stars do not reveal additional DIBs. Comparison of the velocity profile of the strongest of the new DIBs in the sightline toward GCS3-2 (in the GC) with that toward Cygnus OB2 No. 9 and also with the broad velocity profiles of H3+ lines toward GCS3-2 confirm that a significant fraction of the diffuse material producing the DIB absorptions on sightlines to the GC is located within the central few hundred parsecs of the Galaxy.
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Smith, K. T., M. A. Cordiner, and P. J. Sarre. "Diffuse Interstellar Bands as Probes of Small-Scale Interstellar Structure." Proceedings of the International Astronomical Union 9, S297 (May 2013): 141–43. http://dx.doi.org/10.1017/s1743921313015779.
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AbstractWe present observations which probe the small-scale structure of the interstellar medium using diffuse interstellar bands (DIBs). Towards HD 168075/6 in the Eagle Nebula, significant differences in DIB absorption are found between the two lines of sight, which are separated by 0.25 pc, and λ 5797 exhibits a velocity shift. Similar data are presented for four stars in the μ Sgr system. We also present a search for variations in DIB absorption towards κ Vel, where the atomic lines are known to vary on scales of ~ 10 AU. Observations separated by ~ 9 yr yielded no evidence for changes in DIB absorption strength over this scale, but do reveal an unusual DIB spectrum.
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Elyajouri, Meriem, Nick L. J. Cox, and Rosine Lallement. "The 15 273 Å diffuse interstellar band in the dark cloud Barnard 68." Astronomy & Astrophysics 605 (September 2017): L10. http://dx.doi.org/10.1051/0004-6361/201731437.
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High obscuration of background stars behind dark clouds precludes the detection of optical diffuse interstellar bands (DIBs) and hence our knowledge of DIB carriers in these environments. Taking advantage of the reduced obscuration of starlight in the near-infrared (NIR) we used one of the strongest NIR DIBs at 15 273 Å to probe the presence and properties of its carrier throughout the nearby interstellar dark cloud Barnard 68. We measured equivalent widths (EW) for different ranges of visual extinction AV, using VLT/KMOS H-band (1.46–1.85 μm) moderate-resolution (R ~ 4000) spectra of 43 stars situated behind the cloud. To do so, we fitted the data with synthetic stellar spectra from the APOGEE project and TAPAS synthetic telluric transmissions appropriate for the observing site and time period. The results show an increase of DIB EW with increasing AV. However, the rate of increase is much flatter than expected from the EW-AV quasi-proportionality established for this DIB in the Galactic diffuse interstellar medium. Based on a simplified inversion assuming sphericity, it is found that the volume density of the DIB carrier is 2.7 and 7.9 times lower than this expected average value in the external and central regions of the cloud, which have nH≃ 0.4 and 3.5 × 105 cm-3, respectively. Further measurements with multiplex NIR spectrographs should allow detailed modeling of such an edge effect of this DIB and other bands and help clarify its actual origin.
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Nie, T. P., F. Y. Xiang, and Aigen Li. "C60 cation as the carrier of the λ 9577 Å and λ 9632 Å diffuse interstellar bands: further support from the VLT/X-Shooter spectra." Monthly Notices of the Royal Astronomical Society 509, no. 4 (November 12, 2021): 4908–15. http://dx.doi.org/10.1093/mnras/stab3296.
Full textAbstract:
ABSTRACT Ever since they were first detected over 100 yr ago, the mysterious diffuse interstellar bands (DIBs), a set of several hundred broad absorption features seen against distant stars in the optical and near-infrared wavelength range, largely remain unidentified. The close match, both in wavelengths and in relative strengths, recently found between the experimental absorption spectra of gas-phase buckminsterfullerene ions (C$_{60}^{+}$) and four DIBs at $\lambda 9632\, {\rm \mathring{\rm A}}$, $\lambda 9577\, {\rm \mathring{\rm A}}$, $\lambda 9428\, {\rm \mathring{\rm A}}$ and $\lambda 9365\, {\rm \mathring{\rm A}}$ (and, to a lesser degree, a weaker DIB at $\lambda 9348\, {\rm \mathring{\rm A}}$) suggests that C$_{60}^{+}$ is a promising carrier for these DIBs. However, arguments against the C$_{60}^{+}$ identification remain and are mostly concerned with the large variation in the intensity ratios of the $\lambda 9632\, {\rm \mathring{\rm A}}$ and $\lambda 9577\, {\rm \mathring{\rm A}}$ DIBs. In this work, we search for these DIBs in the X-shooter archival data of the European Southern Observatory’s Very Large Telescope, and we identify the $\lambda 9632\, {\rm \mathring{\rm A}}$, $\lambda 9577\, {\rm \mathring{\rm A}}$, $\lambda 9428\, {\rm \mathring{\rm A}}$ and $\lambda 9365\, {\rm \mathring{\rm A}}$ DIBs in a sample of 25 stars. While the $\lambda 9428\, {\rm \mathring{\rm A}}$ and $\lambda 9365\, {\rm \mathring{\rm A}}$ DIBs are too noisy to allow any reliable analysis, the $\lambda 9632\, {\rm \mathring{\rm A}}$ and $\lambda 9577\, {\rm \mathring{\rm A}}$ DIBs are unambiguously detected and, after correcting for telluric water vapour absorption, their correlation can be used to probe their origin. To this end, we select a subsample of nine hot, O- or B0-type stars of which the stellar Mg ii contamination to the $\lambda 9632\, {\rm \mathring{\rm A}}$ DIB is negligibly small. We find that their equivalent widths, after being normalized by reddening to eliminate their common correlation with the density of interstellar clouds, exhibit a tight, positive correlation, supporting C$_{60}^{+}$ as the carrier of the $\lambda 9632\, {\rm \mathring{\rm A}}$ and $\lambda 9577\, {\rm \mathring{\rm A}}$ DIBs.
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Kaper, L. "The Promise of Recent and Future Observatories and Instruments." Proceedings of the International Astronomical Union 9, S297 (May 2013): 389–98. http://dx.doi.org/10.1017/s1743921313016190.
Full textAbstract:
AbstractThe identification of the carrier(s) of diffuse interstellar bands (DIBs) is one of the oldest mysteries in stellar spectroscopy. With the advent of 8-10m-class telescopes substantial progress has been made in measuring the properties of DIBs in the optical and near-infrared wavelength domain, not only in the Galaxy, but also in different environments encountered in Local Group galaxies and beyond. Still, the DIB carriers have remained unidentified. The coming decade will witness the development of extremely large telescopes (GMT, TMT and E-ELT) and their instrumentation. In this overview I will highlight the current instrumentation plan of these future observatories, emphasizing their potential role in solving the enigma of the DIBs.
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Geballe, T. R., F. Najarro, D. de la Fuente, D. F. Figer, A. J. Adamson, and M. G. Rawlings. "The new infrared diffuse interstellar bands in the Galactic center." Proceedings of the International Astronomical Union 9, S303 (October 2013): 75–77. http://dx.doi.org/10.1017/s1743921314000192.
Full textAbstract:
The diffuse interstellar bands (DIBs) are a set of absorption features, some of which are broad (“diffuse”), that are formed in the diffuse ISM. Since their discovery nearly a century ago their numbers have increased to over 500. The strongest of these are known to be ubiquitous in the universe. There is general consensus that they are produced by large carbon-bearing molecules; however, no specific identification of any single DIB has survived scrutiny. The overwhelming majority of DIBs are at optical and very near infrared wavelengths. In 1990 two DIBs were identified in J-band spectra, at 1.18 μm and 1.31 μm by Joblin et al. (1990); until recently these were the longest wavelength examples known.
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Lallement, R., H. C. Chen, L. Puspitarini, P. Bonifacio, C. Babusiaux, and V. Hill. "Towards Extraction of Massive DIB Datasets from Stellar Spectroscopic Surveys." Proceedings of the International Astronomical Union 9, S297 (May 2013): 113–16. http://dx.doi.org/10.1017/s174392131301569x.
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AbstractMedium to high-resolution stellar spectroscopic surveys can potentially be used to build DIB databases by means of automated methods of analysis. Multiplex spectrographs increase strongly those potentialities and allow small-scale variability studies. Because measurements of the stellar parameters are generally the primary goal of the surveys, synthetic spectra can be computed and used to extract DIBs from late-type star data. Large datasets should allow deeper investigations on the DIB variability in response to stellar radiation fields, DIB reddening relationships, and help localizing interstellar clouds. Here we describe our attempts to build and test automated methods adapted to both early and late type stars.
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García-Hernández, D. A. "Diffuse Interstellar Bands in (Proto-) Fullerene-Rich Environments." Proceedings of the International Astronomical Union 9, S297 (May 2013): 208–12. http://dx.doi.org/10.1017/s174392131301586x.
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AbstractThe recent infrared detection of fullerenes (C60 and C70) in Planetary Nebulae (PNe) and R Coronae Borealis (RCB) stars offers a beautiful opportunity for studying the diffuse interstellar bands (DIBs) in sources where fullerenes are abundant. Here we present for the first time a detailed inspection of the optical spectra of the hot RCB star DY Cen and two fullerene PNe (Tc 1 and M 1-20), which permits us to directly explore the fullerenes - DIB connection. The DIB spectrum of DY Cen (García-Hernández et al. 2012a) is remarkably different from that in fullerene PNe (García-Hernández & Díaz-Luis 2013). In particular, Tc 1 displays unusually strong 4428 Å and 6309 Å DIBs, which are normal (or not seen) in DY Cen. On the other hand, DY Cen displays an unusually strong 6284 Å DIB that is found to be normal in fullerene PNe. We also report the detection of new broad and unidentified features centered at 4000 Å and 6525 Å in DY Cen and Tc 1, respectively. We suggest that the new 4000 Å band seen in DY Cen may be related to the circumstellar proto-fullerenes seen at infrared wavelengths (García-Hernández et al. 2012a). However, the intense 4428 Å DIB (probably also the 6309 Å DIB and the new 6525 Å band) may be related to the presence of larger fullerenes (e.g., C80, C240, C320, and C540) and buckyonions (multishell fullerenes such as C60@C240 and C60@C240@C540) in the circumstellar envelope of Tc 1 (García-Hernández & Díaz-Luis 2013).