NASA Scientific and Technical Aerospace Reports

macrospicules. Nearly all of these (32) were of one or the other of two different forms: 15 were in the form of an erupting
loop, and 17 were in the form of a single column spiked jet. The erupting-loop macrospicules are appropriate for producing
the magnetic switchbacks in the polar wind. The spiked-jet macrospicules show the appropriate structure and evolution to be
driven by reconnection between network-scale closed field (a network bipole) and the open field rooted against the closed
field. This evidence for reconnection in a large fraction of our macrospicules (1) suggests that many spicules may be generated
by similar but smaller reconnection events and (2) supports the view that coronal heating and solar wind acceleration in
coronal holes and in quiet regions are driven by explosive reconnection events in the magnetic network.
Author
Magnetic Field Configurations; Solar Corona; Coronal Holes; H Alpha Line; Spicules
20040071143 Smithsonian Astrophysical Observatory, Cambridge, MA, USA
Probing me Reverse Shock in an Oxygen-Rich Supernova Remnant
Gaetz, Terrance; Sonneborn, George, Technical Monitor; May 2004; 2 pp.; In English
Contract(s)/Grant(s): NAG5-12295; No Copyright; Avail: CASI; A01, Hardcopy
The aim of this project is to examine the O VI emission at three positions around the X- ray bright ring of the remnant
in order to investigate the relation between the O VI emission, the X-ray O VII and O VIII emission, and the optical [OIII}
emission, and how these vary around the rim of the remnant. All three pointings and the background pointing have now been
observed; the archive notification for the most recent dataset was Oct 30, 2003. After reprocessing and screening, the net
exposure time for the SE exposure is only 54 percent of the approved time (15 kilosec). for the SE exposure, the available
statistics are not good enough for analysis. A request for reobservation to make up for the lost time in the SE pointing has been
approved. Broad O VI 1032 and O VI 1038 emission is detected with velocity width of at least 800 km/s, and possibly
exceeding 1000 km/s. The Flanagan et al. analysis of the Chandra grating data show bulk velocities in the X-ray gas of order
+/- 1000 km/s. In the region of the FUSE E0lO2-SE pointing, the Chandra data indicate both blue-shifted and red-shifted
emission. Analysis of the velocity structure of the O VI emission will provide additional constraints on the kinematics of the
gas: is it emission from a tilted expanding barrel, or a more symmetric expansion? The O VI fluxes are also needed to assess
whether the O VI is radiation from recombining O VII or instead fiom cooler gas ionizing toward O VII. The emission is faint,
however, which complicates the analysis. Because the lines are so broad, absorption by intervening H2, CII, and foreground
OVI must be considered. A number of stars in the SMC have been observed which provide information on foreground OVI
absorption. The initial analyses have concentrated on the Li1F channel since the guidance is based on that channel. The Li2F
channel is being examined exposure by exposure to see if any of the data can be used to improve the signal to noise in the
Li1F data.
Author
Supernova Remnants; Exposure; Light Emission; Hydrogen; Oxygen; X Rays
20040071150 Alabama Univ., Huntsville, AL, USA
Studying the Accretion Disks in Black Hole X-Ray Binaries with Monte-Carlo Simulations
Yao, Y.; Zhang, S. N.; Zhang, X.; AIP Conference Proceedings; 2001; Volume 587, pp. 106; In English; No Copyright; Avail:
Other Sources
No abstract available
Accretion Disks; Black Holes (Astronomy); X Ray Binaries; Astronomical Models; X Ray Astronomy
20040071152 NASA Goddard Space Flight Center, Greenbelt, MD, USA
Evolution of Iron K Alpha Line Emission in the Black Hole Candidate GX 339-4
Feng, Y. X.; Zhang, S. N.; Sun, X.; Durouchoux, Ph.; Chen, Wan; Cui, Wei; Astrophysical Journal; May 2001; Volume 553,
Issue 1, pp. 394-398; In English
Contract(s)/Grant(s): NAG5-7927; Copyright; Avail: Other Sources; Abstract Only
GX 339-4 was regularly monitored with the Rossi X-Ray Timing Explorer during a period (in 1999) when its X-ray flux
decreased significantly (from 4.26 x 10(exp -10) to 7.6 x 10(exp -12) ergs in the 3-20 keV band), as the source settled into
the ‘off state.’ Our spectral analysis revealed the presence of a prominent iron K alpha line in the observed spectrum of the
source for all observations. The line shows an interesting evolution: it is centered at approx. 6.4 keV when the measured flux
is above 5 x 10(exp -1) ergs per sq cm/s but is shifted to approx. 6.7 keV at lower fluxes. The equivalent width of the line
appears to increase significantly toward lower fluxes, although it is likely to be sensitive to calibration uncertainties. While
the fluorescent emission of neutral or mildly ionized iron atoms in the accretion disk can perhaps account for the 6.4 keV line,
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