12,557 research outputs found
Stellar Wind Accretion in GX301-2: Evidence for a High-density Stream
The X-ray binary system GX301-2 consists of a neutron star in an eccentric
orbit accreting from the massive early-type star WRAY 977. It has previously
been shown that the X-ray orbital light curve is consistent with existence of a
gas stream flowing out from Wray 977 in addition to its strong stellar wind.
Here, X-ray monitoring observations by the Rossi X-ray Timing Explorer (RXTE)/
All-Sky-Monitor (ASM) and pointed observations by the RXTE/ Proportional
Counter Array (PCA) over the past decade are analyzed. We analyze both the flux
and column density dependence on orbital phase. The wind and stream dynamics
are calculated for various system inclinations, companion rotation rates and
wind velocities, as well as parametrized by the stream width and density. These
calculations are used as inputs to determine both the expected accretion
luminosity and the column density along the line-of-sight to the neutron star.
The model luminosity and column density are compared to observed flux and
column density vs. orbital phase, to constrain the properties of the stellar
wind and the gas stream. We find that the change between bright and medium
intensity levels is primarily due to decreased mass loss in the stellar wind,
but the change between medium and dim intensity levels is primarily due to
decreased stream density. The mass-loss rate in the stream exceeds that in the
stellar wind by a factor of 2.5. The quality of the model fits is significantly
better for lower inclinations, favoring a mass for WRAY 977 of 53 to 62 Msun.Comment: 19 pages, 6 figure
Radio Spectrum and Distance of the SNR HB9
New images are presented of the supernova remnant (SNR) HB9 based on 408 MHz
and 1420 MHz continuum emission and HI-line emission data of the Canadian
Galactic Plane Survey (CGPS) by the Dominion Radio Astrophysical Observatory
(DRAO). Two methods of spectral index analysis for HB9 are presented and
compared: one removes compact sources at both frequencies but is limited to the
resolution of the 408 MHz image; the other removes compact sources only in the
1420 MHz image so is effective at higher spatial resolution. The second allows
more detailed spectral index variation studies than the first. The two T-T plot
methods and new integrated flux densities give spectral index
(S_{\nu}\propto\nu^{-alpha}) for the whole of HB9 of 0.48+-0.03; and
0.47+-0.06, respectively. These are lower than previous spectral index for HB9
(alpha=0.61). Spatial variations of spectral index are derived using the second
method and yield a steeper spectral index for interior regions than for the
rim. This can be explained by a standard curved interstellar electron energy
spectrum combined with lower interior magnetic field compared to that near the
outer shock, which results in a larger proportion of steep spectrum emission
for lines-of-sight through the central body of the SNR. HI observations show
structures probably associated with the SNR in the radial velocity range -3 to
-9 km/s and suggest a distance of 0.8+-0.4 kpc for the SNR. This is consistent
with the distance to the radio pulsar 0458+46, offset from the center of HB9 by
23'. However the pulsar spindown and kinematic ages are significantly greater
than estimates of the SNR age: the Sedov age for HB9 is 6600 yr and the
evaporative cloud model yields ages of 4000-7,000 yr.Comment: 8 pages, 6 figures, 1 table, accepted by A&
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Motivational factors and student attitudes in language specific classes with advanced learners of German
This article reports on questionnaire results related to motivational factors and student attitudes towards an international bilingual email project between law and business students in England and Germany. Both groups discussed subject-specific content. At the beginning and the end of the project, students filled in a questionnaire answering questions which were designed to elicit information about their motivation for studying a language in conjunction with their main degree courses in business and law. The term motivation and its use in recent publications is examined and particular emphasis is placed on motivational factors which might be connected to the use of information technology. The study focuses on the results gained from the English groups
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âYou cannot show meâ: Two Tudor Coronation Processions, Shakespeareâs King Henry VIII and the Staging of Anne Boleyn
In this paper, Leahy argues that
Shakespeareâs portrayal of Anne Boleyn in King Henry VIII has traditionally been regarded
as one that does not take account of her ambiguous historical position, and he goes on
to examine this portrayal in the light of her own coronation procession, as well as her
representation in the coronation procession of her daughter, Elizabeth. These
representations of Boleyn are then set against the famous letter written by Sir Henry
Wotton to describe the burning down of the Globe Theatre during a production of
King Henry VIII in 1613. Set within such a context, Leahy argues that the
representation of Anne in the play is not what it has traditionally been made out to be,
but demonstrates the difficulties inherent in staging such a problematic figure
Bilingual negotiation via e-mail: an international project
This article examines selective results of an international e-mail project between 24 students studying law with German (in England) and English (in Germany).1 It refers to outcomes as manifested in the students' written reports and oral assessments, but concentrates on samples of bilingual negotiation between partners as expressed in their e-mails. The article focuses on the design of the project and the socio-cultural environment in which it is situated. Taking into account the relevant research in computer-mediated communication, the design of the project follows two primary objectives: the acquisition of (1) language and (2) content as part of a task-based e-mail exchange
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The Shakespeare authorship question â A suitable subject for academia
This paper considers whether the Shakespeare Authorship Question is a legitimate subject for study in academia
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âThy Hunger-Starved Menâ: Shakespeareâs Henry plays and the contemporary lot of the common soldier
Between 1589 and 1599 Shakespeare wrote six Henry plays, two on the reign of Henry IV, one on that of Henry V and three covering that of Henry VI. An important preoccupation, which runs through all of these plays, is the conditions in which common soldiers lived. The years leading up to the appearance of the first of the plays, 1 Henry VI, saw many outbreaks of discontentment on the part of the soldiers in Elizabeth Iâs army. The mass recruitment of troops for Ireland in the 1590s increased such discontentment. This paper examines the contemporary lot of the common soldiers, and shows that Shakespeareâs interest in their situation was one that articulated pervasive, early modern anxieties
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âAll would be royalâ: The effacement of disunity in Shakespeareâs Henry V
This paper seizes on the unresolved moment of conflict between Henry and the common soldier Williams in Shakespeare's Henry V to demonstrate the ways in which traditional criticism has occluded dissent and co-opted the common soldier on behalf of a perceived empathy towards the king on the part of the author. A look at documented evidence shows that Shakespeare was articulating a common reality in this unresolved moment, one which dsiplays rather than effaces contemporary discontent with the lot of the ordinary soldier
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"For pure need": Violence, terror and the common people in Henry VI, part 2
This paper looks at representations of the common people in Shakespeare's Henry VI, Part 2 and shows how they were subject to the continual threat of violence and terror in Elziabethan society
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