3,641 research outputs found
Small Explorer project: Submillimeter Wave Astronomy Satellite (SWAS). Mission operations and data analysis plan
The Mission Operations and Data Analysis Plan is presented for the Submillimeter Wave Astronomy Satellite (SWAS) Project. It defines organizational responsibilities, discusses target selection and navigation, specifies instrument command and data requirements, defines data reduction and analysis hardware and software requirements, and discusses mission operations center staffing requirements
The central density of R136 in 30 Doradus
The central density rho_0 of a stellar cluster is an important physical
parameter for determining its evolutionary and dynamical state. How much mass
segregation there is, or whether the cluster has undergone core collapse both
depends on rho_0. We reanalyze the results of a previous paper that gives the
mass density profile of R136 and combine them with both a conservative upper
limit for the core parameter and a more uncertain recent measurement. We thus
place a lower limit on rho_0 under reasonable and defensible assumptions about
the IMF, finding rho_0 >~ 1.5x10^4 Msun/pc^3 for the conservative assumption a
< 0.4 pc for the cluster core parameter. If we use the lower, but more
uncertain value a = 0.025 pc, the central density estimate becomes greater than
10^7 Msun/pc^3. A mechanism based on the destruction of a large number of
circumstellar disks is posited to explain the hitherto unexplained increase in
reddening presented in that same work.Comment: 6 pages, 2 figure
High resolution spectroscopy of H II Galaxies: Structure and Supersonic line widths
We present high resolution echelle spectroscopy of a sample of H II galaxies.
In all galaxies we identify different H(alpha) emitting knots along the slit
crossing the nucleus. All of these have been isolated and separately analyzed
through luminosity and size vs diagnosis plots. We find that in all cases, for
a particular galaxy, the bulk of emission comes from their main knot and
therefore, at least for the compact class galaxies we are dealing with,
luminosity and sigma values measured using single aperture observations would
provide similar results to what is obtained with spatially resolved
spectroscopy. In the size vs plots as expected there is a shift in the
correlations depending on whether we are including all emission in a single
point or we split it in its different emitting knots. The problem of a proper
determination of the size of the emitting region so that it can be used to
determine the mass of the system remains open. From the data set gathered,
using the highest surface brightness points as recently proposed by
Fuentes-Masip et al. (2000), the best luminosity vs correlation turns out to be
consistent with a Virial model.Comment: 14 pages, 4 figures, ApJ accepted. Also available from
http://www.daf.on.br/~etelles/papers/wht.ps.g
Radiation from carbon in a rocket plume mixing region with coupled convective and radiative energy fluxes and general optical thickness
Carbon radiant heat transfer from plume mixing region to base of rocket vehicl
Adaptive Optics observations of LBQS 0108+0028: K-band detection of the host galaxy of a radio-quiet QSO at z=2
We report the first unambiguous detection of the host galaxy of a normal
radio-quiet QSO at high-redshift in K-band. The luminosity of the host
comprises about 35% of the total K-band luminosity. Assuming the average colour
of QSOs at z=2, the host would be about 5 to 6 mag brighter than an unevolved
L* galaxy placed at z=2, and 3 to 4 mag brighter than a passively evolved L*
galaxy at the same redshift. The luminosity of the host galaxy of the QSO would
thus overlap with the highest found in radio-loud QSOs and radio-galaxies at
the same redshift.Comment: Accepted to be published in MNRAS. 4 pages, 2 postscript figures.
Also available at http://www.mpa-garching.mpg.de/~itzia
Her Life Depends On It: Sport, Physical Activity and the Health and Well-Being of American Girls
This report is a comprehensive compendium of research that points to physical activity and sport as fundamental solutions for many of the serious health and social problems faced by American girls. An appreciable mass of evidence-based knowledge about girls' involvement with sport and physical activity has been generated during the last decade. The amount and quality of this research are uneven and varied. For example, a good deal of research examines the associations between physical activity and risk for coronary heart disease, but studies that focus on risk for Alzheimer's disease are just beginning to issue. Researchers have verified links between high school athletic participation and teen pregnancy prevention, although more longitudinal research is needed to thoroughly confirm the connections. Overall, however, this report shows that the current state of knowledge on the relationship of physical activity to the health and social needs of American girls warrants the serious attention of public health officials, educators and sport leaders
Her Life Depends on it III: Sport, Physical Activity and the Health and Well-being of American Girls and Women
Her Life Depends On It III is the Women's Sports Foundation's comprehensive report that reviews existing and emerging research on the links between participation in sport and physical activity and the health and wellbeing of American girls and women. As with the previous editions in 2004 and 2009, this study also confirms that physical activity and sport provides the critical foundation, in no small part, that allows girls and women to lead healthy, strong, and fulfilled lives. Ten years since its first publication, the updated Her Life Depends On It provides an even more comprehensive review of the ever-expanding body of research that demonstrates how important it is for girls and women to participate in sport and physical activity. The report's contents reflect the review of 1,500 studies, nearly 400 covered since the previous edition
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