35 research outputs found
The Outer Disks of Early-Type Galaxies. I. Surface-Brightness Profiles of Barred Galaxies
We present a study of 66 barred, early-type (S0-Sb) disk galaxies, focused on
the disk surface brightness profile outside the bar region and the nature of
Freeman Type I and II profiles, their origins, and their possible relation to
disk truncations. This paper discusses the data and their reduction, outlines
our classification system, and presents -band profiles and classifications
for all galaxies in the sample.
The profiles are derived from a variety of different sources, including the
Sloan Digital Sky Survey (Data Release 5). For about half of the galaxies, we
have profiles derived from more than one telescope; this allows us to check the
stability and repeatability of our profile extraction and classification. The
vast majority of the profiles are reliable down to levels of mu_R ~ 27 mag
arcsec^-2; in exceptional cases, we can trace profiles down to mu_R > 28. We
can typically follow disk profiles out to at least 1.5 times the traditional
optical radius R_25; for some galaxies, we find light extending to ~ 3 R_25.
We classify the profiles into three main groups: Type I (single-exponential),
Type II (down-bending), and Type III (up-bending). The frequencies of these
types are approximately 27%, 42%, and 24%, respectively, plus another 6% which
are combinations of Types II and III. We further classify Type II profiles by
where the break falls in relation to the bar length, and in terms of the
postulated mechanisms for breaks at large radii ("classical trunction" of star
formation versus the influence of the Outer Lindblad Resonance of the bar). We
also classify the Type III profiles by the probable morphology of the outer
light (disk or spheroid). Illustrations are given for all cases. (Abridged)Comment: 41 pages, 26 PDF figures. To appear in the Astronomical Journal.
Version with full-resolution figures available at
http://www.mpe.mpg.de/~erwin/research
The First Post-Kepler Brightness Dips of KIC 8462852
We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in October 2015, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and "Angkor", which persist on timescales from several days to weeks. Our main results so far are: (i) there are no apparent changes of the stellar spectrum or polarization during the dips; (ii) the multiband photometry of the dips shows differential reddening favoring non-grey extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale <<1um, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term "secular" dimming, which may be caused by independent processes, or probe different regimes of a single process
Sustainable Human Development: Corporate Challenges and Potentials the Case of Bayer CropScience's Cotton Seed Production in Rural Karnataka (India)
This paper aims to explore concepts, methods and empirical results of potential impacts of Transnational Corporations (TNC) on Sustainable Human Development (SHD) in emerging market countries. In doing so, a further major goal is to explain, illustrate and discuss how the theoretical CA framework used in the GeNECA project2 can be applied to corporate SHD impacts. Our findings are based on the case of Bayer CropScience’s Model Village Project in rural Karnataka, India. To achieve our goals, we first establish a theoretical framework for assessing corporate impacts on SHD to capture SHD effects. Thereafter, we introduce the case of Bayer CropScience’s seed production in rural India, for which a “Model Village Project (MVP)” has been established to explore ways, potentials and challenges of promoting SHD of the villagers and corporate goals in a win-win-strategy. Afterwards, we explain methodological requirements, our representative database for the quantitative analyses, and the qualitative methods that we use for project evaluation. Based on findings of the authors’ external evaluation of the MVP, we discuss the baseline situation in the model villages with respect to corporate potentials, challenges and limitations to foster SHD impacts. Methodologically, we find the combination of quantitative representative methods and qualitative assessments to be most effective to capture corporate potentials and risks. Furthermore it turns out to be promising to extend the analyses beyond standardized benchmarks like the MDGs. We show that major determinants of SHD established in the paper result in a portfolio of corporate opportunities and risks. For instance, the reality of underemployment in the model villages provides specific corporate opportunities like an abundant pool of labor supply. However, it also produces corporate risks, e.g. lack of capital available for necessary investment by suppliers who frequently suffer from poverty, risk of over-indebtedness and a resulting inability to accumulate enough capital and to raise productivity. In the comprehensive opportunity and riskportfolio of this Bayer CropScience case, we find abundant potential business cases which we discuss further in the text. We conclude that corporate potentials as well as risks of corporate neglect and violations of people-centered SHD also depend on how much the villagers are enabled and empowered to make most of their agency as individuals and as groups. Furthermore, it depends on trust building as a prerequisite of awareness raising of the villagers themselves, so that they are willing and able to participate successfully in the undertaken procedures
Dangerous Drug Reactions on the S&A iPhone App [abstract]
Computational Infrastructure and Informatics Poster SessionThe S&A drug database for handhelds, sold to dermatologists for 8 years, was uploaded as a new iPhone application (app), February 2010. Our program notes all warnings at the several FDA levels: boxed warnings, bold warnings, warnings, and adverse effects, reflecting greater interest in drug warnings by all parties, including consumers, regulators, industry. The FDA has a program called MedWatch, which collects reports of adverse drug reactions, including serious and fatal reactions. In 2007, The Institute for Safe Medical Practices (ISMP) published a list of the fifteen drugs most often reported as primary suspects for serious and fatal reactions in the FDA's MedWatch program for the eight years ending in December, 2005. Our iPhone app now notes all drugs which made this list. Using knowledge gained working with the ISMP during summer, 2009, S&A researchers, including 2 S&T seniors, are working with MedWatch data to revise and update the old fatal drug list. The new information will be placed on the S&A website and the iPhone app during Spring, 2010. The quarterly data will allow consumers to see how the fatality rates for different drugs are changing. In addition, the changes will allow S&A to look for a signal for specific reactions. The proportional reporting ratio (PRR) was used to search the MedWatch data from 2004-2008 and discover that ciprofloxacin was the leading primary suspect drug in deaths in elderly patients from severe skin reactions during the period 2004-2008