8,571 research outputs found
The Ulysses Supplement to the BATSE 3B Catalog of Cosmic Gamma-Ray Bursts
We present Interplanetary Network localization information for 218 gamma-ray
bursts in the 3rd BATSE catalog, obtained by analyzing the arrival times of
these bursts at the Ulysses and Compton Gamma-Ray Observatory (CGRO)
spacecraft. For any given burst observed by these two spacecraft, arrival time
analysis (or "triangulation") results in an annulus of possible arrival
directions whose half-width varies between 7 arcseconds and 32 arcminutes,
depending on the intensity and time history of the burst, and the distance of
the Ulysses spacecraft from Earth. This annulus generally intersects the BATSE
error circle, resulting in an average reduction of the error box area of a
factor of 30.Comment: Accepted for publication in the Astrophysical Journal Supplemen
The Interplanetary Network Supplement to the BeppoSAX Gamma-Ray Burst Catalogs
Between 1996 July and 2002 April, one or more spacecraft of the
interplanetary network detected 787 cosmic gamma-ray bursts that were also
detected by the Gamma-Ray Burst Monitor and/or Wide-Field X-Ray Camera
experiments aboard the BeppoSAX spacecraft. During this period, the network
consisted of up to six spacecraft, and using triangulation, the localizations
of 475 bursts were obtained. We present the localization data for these events.Comment: 89 pages, 3 figures. Submitted to the Astrophysical Journal
Supplement Serie
SGR 1806-20 Is a Set of Independent Relaxation Systems
The Soft Gamma Repeater 1806-20 produced patterns of bursts during its 1983
outburst that indicate multiple independent energy accumulation sites, each
driven by a continuous power source, with sudden, incomplete releases of the
accumulated energy. The strengths of the power sources and their durations of
activity vary over several orders of magnitude.Comment: Accepted ApJLett, 15 pages, 3 figure
McScatter: a Simple Three-Body Scattering Package with Stellar Evolution
We describe a simple computer package which illustrates a method of combining
stellar dynamics with stellar evolution. Though the method is intended for
elaborate applications (especially the dynamical evolution of rich star
clusters) it is illustrated here in the context of three-body scattering, i.e.
interactions between a binary star and a field of single stars. We describe the
interface between the dynamics and the two independent packages which describe
the internal evolution of single stars and binaries. We also give an example
application, and introduce a stand alone utility for the visual presentation of
simulation results.Comment: 16 pages, Accepted for publication in New Astronomy. Source codes
available at: http://manybody.org/manybody/McScatter.html and
http://www.manybody.org/manybody/roche.htm
The Ulysses Supplement to the BATSE 4Br Catalog of Cosmic Gamma-Ray Bursts
We present Interplanetary Network localization information for 147 gamma-ray
bursts observed by the Burst and Transient Source Experiment between the end of
the 3rd BATSE catalog and the end of the 4th BATSE catalog, obtained by
analyzing the arrival times of these bursts at the Ulysses and Compton
Gamma-Ray Observatory (CGRO) spacecraft. For any given burst observed by these
two spacecraft, arrival time analysis (or "triangulation") results in an
annulus of possible arrival directions whose half-width varies between 7
arcseconds and 2.3 degrees, depending on the intensity and time history of the
burst, and the distance of the Ulysses spacecraft from Earth. This annulus
generally intersects the BATSE error circle, resulting in an average reduction
of the error box area of a factor of 25.Comment: Accepted for publication in the Astrophysical Journal Supplemen
Feasibility study of an Integrated Program for Aerospace-vehicle Design (IPAD) system. Volume 1: Summary
An overview is provided of the Ipad System, including its goals and objectives, organization, capabilities and future usefulness. The systems implementation is also presented with operational cost summaries
Psycho-social effects of a brain-training program among healthy older adults
Grounded in cognitive neuroscience and social exchange theory, this research evaluated the relationship between changes in cognitive functioning and two psycho-social dimensions of life among healthy adults over the age of 70 (N=12). Specific psycho-social dimensions examined were social interaction and depression. Six females and six males participated in the study. All were white, college-educated individuals residing in a life-care residential retirement community. The participants used the Posit Science® Brain Fitness Program™, an auditory-based computer training program that improves memory and speed of processing, for forty hours over an eight-week period. Pre- and post-tests related to social interaction and depressive symptoms indicated that improvement in cognitive functioning was related to improvement in psychosocial dimensions in later life
Shackleton’s enduring legacy
Sir Ernest Shackleton’s name is one forever associated with the Antarctic Heroic Era (1895–1922), the latter year being that of his death. Shackleton was an intrepid explorer, voyaging to Antarctica four times and is often compared to contemporary explorers Roald Amundsen, Douglas Mawson and Robert Falcon Scott. Shackleton’s achievements are a result of a combination of natural leadership and finely-tuned management skills, assisted by a strong element of luck. This paper explores Shackleton’s enduring legacy through the contemporary lens of scientific discovery and exploration, modern leadership training methods and management techniques, and observations of his influence upon Antarctic tourism, particularly “adventure” tourism
No Evidence for Gamma-Ray Burst/Abell Cluster or Gamma- Ray Burst/Radio-Quiet Quasar Correlations
We examine the recent claims that cosmic gamma-ray bursts are associated with
either radio-quiet quasars or Abell clusters. These associations were based on
positional coincidences between cataloged quasars or Abell clusters, and
selected events from the BATSE 3B catalog of gamma-ray bursts. We use a larger
sample of gamma-ray bursts with more accurate positions, obtained by the 3rd
Interplanetary Network, to re-evaluate these possible associations. We find no
evidence for either.Comment: Accepted for publication in the Astrophysical Journa
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