4,468 research outputs found
Sport is king: an investigation into local media coverage of women's sport in the UK East Midlands
There has been a recent interest in research into national media coverage of female sport, particularly single events, but on-going sporting activities by women are rarely reported. This paper attempts to examine this subject at the local level, looking in general at women’s sport and in particular at women’s football in the East Midlands region of the UK. Quantitative methods were used to survey local newspapers and radio stations and interviews were carried out with a range of people relevant to the field of study. The topic of sports media is framed here with reference to research into masculinities and a socialist feminist approach is used to address problems. The data showed there was a significant and on-going imbalance in the amount of coverage and even some signs of a decline in women’s football reporting, in spite of a national resurgence of the sport itself. The authors try to account for this and suggest further areas of future study
Asteroids Observed by The Sloan Digital Sky Survey
We announce the first public release of the SDSS Moving Object Catalog, with
SDSS observations for 58,117 asteroids. The catalog lists astrometric and
photometric data for moving objects observed prior to Dec 15, 2001, and also
includes orbital elements for 10,592 previously known objects. We analyze the
correlation between the orbital parameters and optical colors for the known
objects, and confirm that asteroid dynamical families, defined as clusters in
orbital parameter space, also strongly segregate in color space. Their
distinctive optical colors indicate that the variations in chemical composition
within a family are much smaller than the compositional differences between
families, and strongly support earlier suggestions that asteroids belonging to
a particular family have a common origin.Comment: 6 pages, 1 color figure, to be presented at "Astronomical Telescopes
& Instrumentation", SPIE 200
A Modified Magnitude System that Produces Well-Behaved Magnitudes, Colors, and Errors Even for Low Signal-to-Noise Ratio Measurements
We describe a modification of the usual definition of astronomical
magnitudes, replacing the usual logarithm with an inverse hyperbolic sine
function; we call these modified magnitudes `asinh magnitudes'. For objects
detected at signal-to-noise ratios of greater than about five, our modified
definition is essentially identical to the traditional one; for fainter objects
(including those with a formally negative flux) our definition is well behaved,
tending to a definite value with finite errors as the flux goes to zero.
This new definition is especially useful when considering the colors of faint
objects, as the difference of two `asinh' magnitudes measures the usual flux
ratio for bright objects, while avoiding the problems caused by dividing two
very uncertain values for faint objects.
The Sloan Digital Sky Survey (SDSS) data products will use this scheme to
express all magnitudes in their catalogs.Comment: 11 pages, including 3 postscript figures. Submitted to A
Mechanisms of spin-dependent dark conductivity in films of a soluble fullerene derivative under bipolar injection
pre-printWe report room-temperature pulsed electrically detected magnetic resonance measurements of the dark conductivity of films of the fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) under bipolar (electron-hole) and unipolar (electron-rich) injection conditions. Directly after material deposition, no detectable spin-dependent processes are observed, yet after storage under ambient conditions for more than a day, two distinct spin-dependent mechanisms are found under bipolar injection, suggesting the involvement of degradation-induced electronic states. Spin-Rabi beat oscillation measurements show that at least one of these processes is due to weakly spin-coupled pairs with s = 1/2. The absence of these signals when hole injection is impeded by a barrier suggests that they are due to spin-dependent recombination. The presence of recombination confirms that fullerenes are both electron and hole acceptors, with important consequences for the design, operation, and understanding of plastic solar cells. Electron-hole recombination can occur within homogeneous domains of either the donor or the acceptor of the bulk heterojunction structure, constituting an important dissipative channel in addition to the established interfacial bimolecular recombination loss
Wavelength Dependent PSFs and their impact on Weak Lensing Measurements
We measure and model the wavelength dependence of the PSF in the Hyper
Suprime-Cam (HSC) Subaru Strategic Program (SSP) survey. We find that PSF
chromaticity is present in that redder stars appear smaller than bluer stars in
the and -bands at the 1-2 per cent level and in the and
-bands at the 0.1-0.2 per cent level. From the color dependence of the PSF,
we fit a model between the monochromatic PSF trace radius, , and wavelength
of the form . We find values of between -0.2
and -0.5, depending on the epoch and filter. This is consistent with the
expectations of a turbulent atmosphere with an outer scale length of m, indicating that the atmosphere is dominating the chromaticity. We
find evidence in the best seeing data that the optical system and detector also
contribute some wavelength dependence. Meyers and Burchat (2015) showed that
must be measured to an accuracy of not to dominate the
systematic error budget of the Large Synoptic Survey Telescope (LSST) weak
lensing (WL) survey. Using simple image simulations, we find that can be
inferred with this accuracy in the and -bands for all positions in the
LSST field of view, assuming a stellar density of 1 star arcmin and that
the optical PSF can be accurately modeled. Therefore, it is possible to correct
for most, if not all, of the bias that the wavelength-dependent PSF will
introduce into an LSST-like WL survey.Comment: 14 pages, 10 figures. Submitted to MNRAS. Comments welcom
A method for optimal image subtraction
We present a new method designed for optimal subtraction of two images with
different seeing. Using image subtraction appears to be essential for the full
analysis of the microlensing survey images, however a perfect subtraction of
two images is not easy as it requires the derivation of an extremely accurate
convolution kernel. Some empirical attempts to find the kernel have used the
Fourier transform of bright stars, but solving the statistical problem of
finding the best kernel solution has never really been tackled. We demonstrate
that it is possible to derive an optimal kernel solution from a simple least
square analysis using all the pixels of both images, and also show that it is
possible to fit the differential background variation at the same time. We also
show that PSF variations can also be easily handled by the method. To
demonstrate the practical efficiency of the method, we analyzed some images
from a Galactic Bulge field monitored by the OGLE II project.
We find that the residuals in the subtracted images are very close to the
photon noise expectations. We also present some light curves of variable stars,
and show that, despite high crowding levels, we get an error distribution close
to that expected from photon noise alone. We thus demonstrate that nearly
optimal differential photometry can be achieved even in very crowded fields. We
suggest that this algorithm might be particularly important for microlensing
surveys, where the photometric accuracy and completeness levels could be very
significantly improved by using this method.Comment: 8,pages, 4 Postscript figures, emulateapj.sty include
An Efficient Targeting Strategy for Multiobject Spectrograph Surveys: the Sloan Digital Sky Survey "Tiling" Algorithm
Large surveys using multiobject spectrographs require automated methods for deciding how to efficiently point observations and how to assign targets to each pointing. The Sloan Digital Sky Survey (SDSS) will observe around 10 6 spectra from targets distributed over an area of about 10,000 deg2, using a multiobject fiber spectrograph that can simultaneously observe 640 objects in a circular field of view (referred to as a "tile") 1°.49 in radius. No two fibers can be placed closer than 55Prime; during the same observation; multiple targets closer than this distance are said to "collide." We present here a method of allocating fibers to desired targets given a set of tile centers that includes the effects of collisions and that is nearly optimally efficient and uniform. Because of large-scale structure in the galaxy distribution (which form the bulk of the SDSS targets), a naive covering of the sky with equally spaced tiles does not yield uniform sampling. Thus, we present a heuristic for perturbing the centers of the tiles from the equally spaced distribution that provides more uniform completeness. For the SDSS sample, we can attain a sampling rate of greater than 92% for all targets, and greater than 99% for the set of targets that do not collide with each other, with an efficiency greater than 90% (defined as the fraction of available fibers assigned to targets). The methods used here may prove useful to those planning other large surveys
- …