3,032 research outputs found

    Surface brightness measurements for APM galaxies

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    This paper considers some simple surface brightness (SB) estimates for galaxies in the Automated Plate Measuring Machine (APM) catalogue in order to derive homogeneous SB data for a very large sample of faint galaxies. The isophotal magnitude and area are used to estimate the central surface brightness and total magnitude based on the assumption of an exponential SB profile. The surface brightness measurements are corrected for field effects on each UK Schmidt plate and the zero-point of each plate is adjusted to give a uniform sample of SB and total magnitude estimates over the whole survey. Results are obtained for 2.4 million galaxies with blue photographic magnitudes brighter than b_J = 20.5 covering 4300 deg^2 in the region of the south galactic cap. Almost all galaxies in our sample have central surface brightness in the range 20 to 24 b_J mag per arcsec^2. The SB measurements we obtain are compared to previous SB measurements and we find an acceptable level of error of +/- 0.2 b_J mag per arcsec^2. The distribution of SB profiles is considered for different galaxy morphologies for the bright APM galaxies. We find that early-type galaxies have more centrally concentrated profiles.Comment: 14 pages, 17 figures, accepted for publication in MNRA

    Durability of reflecting surfaces used in solar heliostats

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    Issued as Project status reports no. 2-9, and Final report, Project no. A-2916Library does not have: Project status report no.

    North Carolina\u27s (f)(1) Mitigating Circumstance: Does It Truly Serve to Mitigate?

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    The purpose of this article is to bring awareness to the misapplication of North Carolina\u27s (f)(1) mitigating circumstance. Part II provides the legal development of the Eighth Amendment in the United States Supreme Court. Part III provides a background on North Carolina\u27s death penalty scheme. Part IV addresses North Carolina law on mitigating circumstances. Finally, Part V provides analogous situations in the criminal law of North Carolina where the same acts admitted under the (f)(1) mitigating circumstance are treated as significant , including The Structured Sentencing Act, The Habitual Offender Act, and the submission of the (e)(3) aggravating circumstance and the (f)(1) mitigating circumstance in the same case

    Disease as a Larval Mortality Factor in Alfalfa Weevil, \u3ci\u3eHypera Postica\u3c/i\u3e (Coleoptera: Curculionidae) Populations in Illinois

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    During the 1974 growing season, larvae of the alfalfa weevil, Hypera postica (Gyllenhal), were examined for pathogens. Three larvae out of 715 examined were infected with a microsporidium. This infection was present in both Washington and Mason counties in Illinois

    Two-Dimensional Topology of the 2dF Galaxy Redshift Survey

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    We study the topology of the publicly available data released by the 2dFGRS. The 2dFGRS data contains over 100,000 galaxy redshifts with a magnitude limit of b_J=19.45 and is the largest such survey to date. The data lie over a wide range of right ascension (75 degree strips) but only within a narrow range of declination (10 degree and 15 degree strips). This allows measurements of the two-dimensional genus to be made. The NGP displays a slight meatball shift topology, whereas the SGP displays a bubble like topology. The current SGP data also have a slightly higher genus amplitude. In both cases, a slight excess of overdense regions are found over underdense regions. We assess the significance of these features using mock catalogs drawn from the Virgo Consortium's Hubble Volume LCDM z=0 simulation. We find that differences between the NGP and SGP genus curves are only significant at the 1 sigma level. The average genus curve of the 2dFGRS agrees well with that extracted from the LCDM mock catalogs. We compare the amplitude of the 2dFGRS genus curve to the amplitude of a Gaussian random field with the same power spectrum as the 2dFGRS and find, contradictory to results for the 3D genus of other samples, that the amplitude of the GRF genus curve is slightly lower than that of the 2dFGRS. This could be due to a a feature in the current data set or the 2D genus may not be as sensitive as the 3D genus to non-linear clustering due to the averaging over the thickness of the slice in 2D. (Abridged)Comment: Submitted to ApJ A version with Figure 1 in higher resolution can be obtained from http://www.physics.drexel.edu/~hoyle

    Redshifts in the Southern Abell Redshift Survey Clusters. I. The Data

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    The Southern Abell Redshift Survey contains 39 clusters of galaxies with redshifts in the range 0.0 < z < 0.31 and a median redshift depth of z = 0.0845. SARS covers the region 0 21h (while avoiding the LMC and SMC) with b > 40. Cluster locations were chosen from the Abell and Abell-Corwin-Olowin catalogs while galaxy positions were selected from the Automatic Plate Measuring Facility galaxy catalog with extinction-corrected magnitudes in the range 15 <= b_j < 19. SARS utilized the Las Campanas 2.5 m duPont telescope, observing either 65 or 128 objects concurrently over a 1.5 sq deg field. New redshifts for 3440 galaxies are reported in the fields of these 39 clusters of galaxies.Comment: 20 pages, 5 figures, accepted for publication in the Astronomical Journal, Table 2 can be downloaded in its entirety from http://trotsky.arc.nasa.gov/~mway/SARS1/sars1-table2.cs

    The visceral embodiment of digital pleasures

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    This panel explores digital pleasures that arise through the entanglement of bodies and digital technologies. Focusing on the digital structures and affordances that facilitate seeking, receiving and giving pleasure we analyse the ways in which intimacy is not only interactive, but also profoundly embodied. Haraway’s work in particular highlights the importance of taking seriously the nexus of human bodies and technologies and attending to the ways in which technologies not only deliver and mediate pleasure, but potentially expand upon our capacity to experience it. This panel explores how mediated practices engage the body as a site of pleasure and embodied affective intensity. Within this frame, we suggest that digitally mediated pleasures, while widely consumed, still have a hint of the ‘fringe’ or ‘subversive’. As well as proposing a theoretical framework for understanding embodied digital pleasures, this panel also examines specific examples of digital pleasure from sex to drugs and sound. To date the research corpus has largely focused upon the micro-social interactions of digital intimacies. This emphasis on relational intimacy puts the body into the background of the digitally mediated encounter and limits the ways in which we can talk about embodiment, sex and pleasure online. Embodied pleasure is intrinsic to the human condition, and digital media is deeply embedded in contemporary life. How these intersect is a key piece of the puzzle of what it means to be human in contemporary society

    Probing dark energy with steerable wavelets through correlation of WMAP and NVSS local morphological measures

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    Using local morphological measures on the sphere defined through a steerable wavelet analysis, we examine the three-year WMAP and the NVSS data for correlation induced by the integrated Sachs-Wolfe (ISW) effect. The steerable wavelet constructed from the second derivative of a Gaussian allows one to define three local morphological measures, namely the signed-intensity, orientation and elongation of local features. Detections of correlation between the WMAP and NVSS data are made with each of these morphological measures. The most significant detection is obtained in the correlation of the signed-intensity of local features at a significance of 99.9%. By inspecting signed-intensity sky maps, it is possible for the first time to see the correlation between the WMAP and NVSS data by eye. Foreground contamination and instrumental systematics in the WMAP data are ruled out as the source of all significant detections of correlation. Our results provide new insight on the ISW effect by probing the morphological nature of the correlation induced between the cosmic microwave background and large scale structure of the Universe. Given the current constraints on the flatness of the Universe, our detection of the ISW effect again provides direct and independent evidence for dark energy. Moreover, this new morphological analysis may be used in future to help us to better understand the nature of dark energy.Comment: 12 pages, 10 figures, replaced to match version accepted by MNRA

    TASS Mark IV Photometric Survey of the Northern Sky

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    The Amateur Sky Survey (TASS) is a loose confederation of amateur and professional astronomers. We describe the design and construction of our Mark IV systems, a set of wide-field telescopes with CCD cameras which take simultaneous images in the VV and ICI_C passbands. We explain our observational procedures and the pipeline which processes and reduces the images into lists of stellar positions and magnitudes. We have compiled a large database of measurements for stars in the northern celestial hemisphere with VV-band magnitudes in the range 7 < V < 13. This paper describes data taken over the four-year period starting November, 2001. One of our results is a catalog of repeated measurements on the Johnson-Cousins system for over 4.3 million stars.Comment: Accepted for publication in December, 2006, issue of PASP. 44 pages including 20 figures. Patches catalog available at http://spiff.rit.edu/tass/patches
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