357 research outputs found

    The development of structural adhesive systems suitable for use with liquid oxygen Annual summary report, 1 Jul. 1964 - 30 Jun. 1965

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    Preparation and testing of adhesive polyurethanes, polycarbonates, and other highy halogenated polymers for liquid oxygen compatibilit

    Spatially-Resolved Spectra of the "Teacup" AGN: Tracing the History of a Dying Quasar

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    The Sloan Digital Sky Survey (SDSS) Galaxy Zoo project has revealed a number of spectacular galaxies possessing Extended Emission-Line Regions (EELRs), the most famous being Hanny's Voorwerp galaxy. We present another EELR object discovered in the SDSS endeavor: the Teacup Active Galactic Nucleus (AGN), nicknamed for its EELR, which has a handle like structure protruding 15 kpc into the northeast quadrant of the galaxy. We analyze physical conditions of this galaxy with long-slit ground based spectroscopy from Lowell, Lick, and KPNO observatories. With the Lowell 1.8m Perkin's telescope we took multiple observations at different offset positions, allowing us to recover spatially resolved spectra across the galaxy. Line diagnostics indicate the ionized gas is photoionized primarily by the AGN. Additionally we are able to derive the hydrogen density from the [S II] 6716/6731 ratio. We generated two-component photoionization models for each spatially resolved Lowell spectrum. These models allow us to calculate the AGN bolometric luminosity seen by the gas at different radii from the nuclear center of the Teacup. Our results show a drop in bolometric luminosity by more than two orders of magnitude from the EELR to the nucleus, suggesting that the AGN has decreased in luminosity by this amount in a continuous fashion over 46,000 years, supporting the case for a dying AGN in this galaxy independent of any IR based evidence. We demonstrate that spatially resolved photoionization modeling could be applied to EELRs to investigate long time scale variability.Comment: 38 pages, 11 figures, accepted for publication in the Astrophysical Journa

    A Multi-Wavelength Study of the Nature of Type 1.8/1.9 Seyfert Galaxies

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    We focus on determining the underlying physical cause of a Seyfert galaxy's appearance as type a 1.8 or 1.9. Are these "intermediate" Seyfert types typical Seyfert 1 nuclei with reddened broad-line regions? Or are they objects with intrinsically weak continua and broad emission lines? We compare measurements of the optical reddening of the narrow and broad-line regions with each other and with the X-ray column derived from XMM-Newton 0.5-10 keV spectra to determine the presence and location of dust in the line of sight. We also searched the literature to see if the objects showed evidence for broad-line variability, and determined if the changes were consistent with a change in reddening or a change in the intrinsic ionizing continuum flux. We find that 10 of 19 objects previously classified as Seyfert 1.8/1.9s received this designation due to their low continuum flux. In four objects the classification was due to BLR reddening, either by the torus or dust structures in the vicinity of the NLR; in the remaining five objects there is not sufficient evidence to favor one scenario over the other. These findings imply that, in general, samples of 1.8/1.9s are not suitable for use in studies of the gas and dust in the central torus.Comment: 85 pages, accepted by Ap

    Reverberation Mapping Results for Five Seyfert 1 Galaxies

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    We present the results from a detailed analysis of photometric and spectrophotometric data on five Seyfert 1 galaxies observed as a part of a recent reverberation mapping program. The data were collected at several observatories over a 140-day span beginning in 2010 August and ending in 2011 January. We obtained high sampling-rate light curves for Mrk 335, Mrk 1501, 3C120, Mrk 6, and PG2130+099, from which we have measured the time lag between variations in the 5100 Angstrom continuum and the H-beta broad emission line. We then used these measurements to calculate the mass of the supermassive black hole at the center of each of these galaxies. Our new measurements substantially improve previous measurements of MBH and the size of the broad line-emitting region for four sources and add a measurement for one new object. Our new measurements are consistent with photoionization physics regulating the location of the broad line region in active galactic nuclei.Comment: 45 pages, 5 figures. Accepted for publication in ApJ. For a brief video explaining the key results of this paper, see http://www.youtube.com/user/OSUAstronom

    Reverberation Mapping of the Seyfert 1 Galaxy NGC 7469

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    A large reverberation mapping study of the Seyfert 1 galaxy NGC 7469 has yielded emission-line lags for Hbeta 4861 and He II 4686 and a central black hole mass measurement of about 10 million solar masses, consistent with previous measurements. A very low level of variability during the monitoring campaign precluded meeting our original goal of recovering velocity-delay maps from the data, but with the new Hbeta measurement, NGC 7469 is no longer an outlier in the relationship between the size of the Hbeta-emitting broad-line region and the AGN luminosity. It was necessary to detrend the continuum and Hbeta and He II 4686 line light curves and those from archival UV data for different time-series analysis methods to yield consistent results.Comment: 9 Pages, 7 figures, 6 tables. Accepted for publication in The Astrophysical Journa

    The ‘one who knocks’ and the ‘one who waits’: Gendered violence in Breaking Bad

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    This article provides a cultural criminological analysis of the acclaimed US television series, Breaking Bad. It is argued here that – as a cultural text – Breaking Bad is emblematic of an agenda for change surrounding criminological theories of peoples’ propensity to do harm to one another. To exemplify this, the show’s central (male) protagonist is revealed to undergo a complete biosocial transformation into a violent offender and, as such, to demonstrate the need for criminological theory to recognise and further reflect upon this process. However, at the same time, the (re)presented inability of the show’s female characters to do the same is indicative of a number of gender-related questions that progressive criminological theories of violence need to answer. In considering these two fields in tandem, the show’s criminological significance is established; it is symbolic of the need for criminology to afford greater recognition to the nuanced intersections of both biological and sociological factors in the genesis and evolution of violent human subjectivities

    Johnston Press and the Crisis in Ireland's Local Newspaper Industry, 2005-2014

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    Reflecting international trends, Ireland’s local newspaper industry has suffered steep circulation and advertising revenue falls since the late-2000s, and has struggled to reshape traditional business models for the digital era. In harsh trading conditions, local titles are operating on reduced editorial resources and are weakened in their capacity to fulfil their traditional watchdog and informed-citizenry functions. Perhaps no company better encapsulates the industry’s recent difficulties than UK media group Johnston Press. In 2005, it paid more than €200m to acquire fourteen local titles in Ireland, but nine years later sold them for just €8.5m. The article draws on this case-study to consider wider issues related to the corporatisation of local news provision, the sustainability of local news industries in small media markets such as Ireland’s, and the increasing disconnect between local journalism’s commodity value and its public good value

    No iron fertilization in the equatorial Pacific Ocean during the last ice age

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    The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron1. Greater atmospheric dust deposition2 could have fertilized the equatorial Pacific with iron during the last ice age—the Last Glacial Period (LGP) but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the 232Th proxy), phytoplankton productivity (using opal, 231Pa/230Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound δ15N) from six cores in the central equatorial Pacific for the Holocene (0–10,000 years ago) and the LGP (17,000–27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region7,8. Thus, ice-age iron fertilization in the Subantarctic Zone would have ultimately worked to lower, not raise, equatorial Pacific productivity

    Methods to identify the target population: implications for prescribing quality indicators

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    Background: Information on prescribing quality is increasingly used by policy makers, insurance companies and health care providers. For reliable assessment of prescribing quality it is important to correctly identify the patients eligible for recommended treatment. Often either diagnostic codes or clinical measurements are used to identify such patients. We compared these two approaches regarding the outcome of the prescribing quality assessment and their ability to identify treated and undertreated patients. Methods: The approaches were compared using electronic health records for 3214 diabetes patients from 70 general practitioners. We selected three existing prescribing quality indicators (PQI) assessing different aspects of treatment in patients with hypertension or who were overweight. We compared population level prescribing quality scores and proportions of identified patients using definitions of hypertension or being overweight based on diagnostic codes, clinical measurements or both. Results: The prescribing quality score for prescribing any antihypertensive treatment was 93% (95% confidence interval 90-95%) using the diagnostic code-based approach, and 81% (78-83%) using the measurement-based approach. Patients receiving antihypertensive treatment had a better registration of their diagnosis compared to hypertensive patients in whom such treatment was not initiated. Scores on the other two PQI were similar for the different approaches, ranging from 64 to 66%. For all PQI, the clinical measurement -based approach identified higher proportions of both well treated and undertreated patients compared to the diagnostic code -based approach. Conclusions: The use of clinical measurements is recommended when PQI are used to identify undertreated patients. Using diagnostic codes or clinical measurement values has little impact on the outcomes of proportion-based PQI when both numerator and denominator are equally affected. In situations when a diagnosis is better registered for treated than untreated patients, as we observed for hypertension, the diagnostic code-based approach results in overestimation of provided treatment
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