410 research outputs found

    High angular resolution cosmic X-ray astronomy observations in the energy range 0.15-2 keV and XUV observations of nearby stars from an attitude controlled rocket

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    The construction of a two dimensional focusing Wolter Type I mirror system for X-ray and XUV astronomical observations from an Astrobee F sounding rocket is described. The mirror design goal will have a one degree field, a 20-arc seconds resolution, an effective area of about 50 sq cm at 1 keV and 10 sq cm at 0.25 keV on axis. A star camera provides aspect data to about 15-arc seconds. Two detectors are placed at the focus with an interchange mechanism to allow a detector change during flight. The following specific developments are reported: (1) position sensitive proportional counter development; (2) channel plate multiplier development; (3) telescope mirror development and payload structure; (4) Australian rocket flight results; (5) Comet Kohoutek He I observation; and (6) Vela, Puppis A, and Gem-Mon bright patch observations

    Support of selected X-ray studies to be performed using data from the Uhuru (SAS-A) satellite

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    A new measurement of the diffuse X-ray emission sets more stringent upper limits on the fluctuations of the background and on the number counts of X-ray sources with absolute value of b 20 deg than previous measurements. A random sample of background data from the Uhuru satellite gives a relative fluctuation in excess of statistics of 2.0% between 2.4 and 6.9 keV. The hypothesis that the relative fluctuation exceeds 2.9% can be rejected at the 90% confidence level. No discernable energy dependence is evident in the fluctuations in the pulse height data, when separated into three energy channels of nearly equal width from 1.8 to 10.0 keV. The probability distribution of fluctuations was convolved with the photon noise and cosmic ray background deviation (obtained from the earth-viewing data) to yield the differential source count distribution for high latitude sources. Results imply that a maximum of 160 sources could be between 1.7 and 5.1 x 10 to the -11 power ergs/sq cm/sec (1-3 Uhuru counts)

    Surface brightness measurements of supernova remanants in the energy band 0.15 - 4 keV and an XUV survey from an altitude controlled rocket

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    Reports are presented concerning the flight of Aerobee 170, 13.063 UG. The papers presented include: soft X-rays for Cygnus X-1 and Cygnus X-2; X-ray spectrum of the entire Cygnus loop; X-ray surface brightness of the Cygnus loop; and observations of He II 304 A and He I 584 a nightglow

    Solar X-rays scattered by Venus, Mars and the Moon

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    Scattering process of solar X rays with photoionization fluorescence by planetary atmosphere

    A search for X-ray pulsations from the galactic center

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    Data from the SAS-3 satellite were used in a search for X-ray pulsations from the direction of the galactic center. No periodic X-ray behavior was detected in the frequency interval 0.6 Hz to 0.0006 Hz and energy range 2.5 - 35 keV. For periods less than 60 sec, the upper limit to the amplitude of any pulsation in the 2.5 - 10 keV band is approximately .0017 cts/sq cm/s. This corresponds to a pulsed fraction of approximately 1.3 percent of the total GCX flux. Somewhat higher limits apply for longer periods and for energies greater than 10 keV
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