715 research outputs found

    Abundance stratification in Type Ia supernovae - V. SN 1986G bridging the gap between normal and subluminous SNe Ia

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    A detailed spectroscopic analysis of SN 1986G has been performed. SN 1986G `bridges the gap' between normal and sub luminous type Ia supernova (SNe Ia). The abundance tomography technique is used to determine the abundance distribution of the elements in the ejecta. SN 1986G was found to be a low energy Chandrasekhar mass explosion. Its kinetic energy was 70% of the standard W7 model (0.9x1051^{51}erg). Oxygen dominates the ejecta from the outermost layers down to ∼\sim9000kms−1^{-1} , intermediate mass elements (IME) dominate from ∼\sim 9000kms−1^{-1} to ∼\sim 3500kms−1^{-1} with Ni and Fe dominating the inner layers <∼<\sim 3500kms−1^{-1}. The final masses of the main elements in the ejecta were found to be, O=0.33M, IME=0.69M, stable NSE=0.21M, 56^{56}Ni=0.14M. An upper limit of the carbon mass is set at C=0.02M. The spectra of SN1986G consist of almost exclusively singly ionised species. SN1986G can be thought of as a low luminosity extension of the main population of SN Ia, with a large deflagration phase that produced more IMEs than a standard SN Ia.Comment: Accepted for publication in MNRAS, update

    Gathering Data

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    In 2012, RICS developed a methodology to calculate the embodied carbon of construction materials issued as an information paper. A guidance note is due for release later this year, with a Code of Practice and practice statement also likely to be published. This RICS guidance will then become mandatory. In Construction Journal April/May, we considered embodied carbon and carbon accounting. Here we investigate how the existing guidance could be expanded on to assess the true carbon cost of new sustainable technologies. It is considered that between 85% and 97% of the buildings in existence within the UK in 2006 will remain in use in 2050. To meet the government’s demanding carbon reduction targets set for that year, the majority of these buildings will need to consider sustainable refurbishment of some form or other. In an ideal situation, all buildings would take a ‘fabric-first’ approach and apply passive design rather than relying on technical solutions. In reality, a large number of buildings will require an ‘embodied carbon intensive’ technical solution. How significant is this stage, and can the new RICS guidance be expanded on to include all sustainable technologies

    Surface Plasmons on Complex Symmetry Nanostructured Arrays

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    A Declaration of Helsinki for animals

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    Costing Carbon

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    In 2010, the UK government’s Low Carbon Construction Innovation and Growth Team report recommended that the Treasury Green Book require whole-life carbon appraisal of proposals before public funds are committed. In response, RICS developed a methodology to calculate the embodied carbon of construction materials. After a 2012 information paper, a guidance note is due for release in April 2014 (see page 25) with a Code of Practice and Practice Statement likely to follow, on which this RICS guidance will become mandatory. Is this the precursor for placing a cost on carbon

    Breaking the color-reddening degeneracy in type Ia supernovae

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    A new method to study the intrinsic color and luminosity of type Ia supernovae (SNe Ia) is presented. A metric space built using principal component analysis (PCA) on spectral series SNe Ia between -12.5 and +17.5 days from B maximum is used as a set of predictors. This metric space is built to be insensitive to reddening. Hence, it does not predict the part of color excess due to dust-extinction. At the same time, the rich variability of SN Ia spectra is a good predictor of a large fraction of the intrinsic color variability. Such metric space is a good predictor of the epoch when the maximum in the B-V color curve is reached. Multivariate Partial Least Square (PLS) regression predicts the intrinsic B band light-curve and the intrinsic B-V color curve up to a month after maximum. This allows to study the relation between the light curves of SNe Ia and their spectra. The total-to-selective extinction ratio RV in the host-galaxy of SNe Ia is found, on average, to be consistent with typical Milky-Way values. This analysis shows the importance of collecting spectra to study SNe Ia, even with large sample publicly available. Future automated surveys as LSST will provide a large number of light curves. The analysis shows that observing accompaning spectra for a significative number of SNe will be important even in the case of "normal" SNe Ia.Comment: 11 pages, 11 figure

    Kinship Health Relationships: Reconfiguring the ‘good death’ in mixed species families.

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    Through an innovative interspecies analysis, this article explores narratives surrounding the medical treatment of humans and pet animals at the end of life among UK veterinary surgeons, medical practitioners and members of the public. Contrasting the care options open to pet owners with those available to human patients, and through a thematic focus on treatments and medicines, euthanasia and palliation, this article pays close attention to the ways that practitioners and members of the public make sense of - and express ideas about - interspecies family kinship at the end of a life. We highlight the utility of interactionist approaches for understanding microsocial human-animal kinship ties and argue that health policy and practice during end-of-life care should better reflect the lived reality of the multispecies family. In so doing, we highlight the significance and complexities of interspecies conversations for the development of contemporary end-of-life care debates. Keywords: ‘good death’, end-of-life care, clinical responsibility, euthanasia, palliative care, animal-human relations; pets; posthumanism; kinship
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