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Results for “STELLAR SPECTRUM”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
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NASA NTRS1991

Status of the Stellar X-Ray Polarimeter for the Spectrum-X-Gamma mission

The Stellar X-Ray Polarimeter (SXRP) uses the polarization sensitivity of a graphite Bragg crystal and a lithium Thomsom scattering target to measure the polarization of X-rays from astrophysical sources. The SXRP is a focal plane detector for the Soviet-Danish SODART telescopes which will be launched on the Soviet Spectrum-X-Gamma mission. The SXRP will be the third orbiting stellar X-ray polarimeter, and should provide an order of magnitude increase in polarization sensitivity over its predecessors.

Kaaret, P.↗
NASA NTRS1964

Comments on convection

Convection role on integrated absorption lines in stellar atmosphere models

ABSORPTION SPECTRUM↗
NASA NTRS1984

The extragalactic nature of H0323+022

Imaging and spectroscopic observations probed the nature of the X-ray source H0323+022. It is suggested that H0323+022 is extragalactic, and similar to a variety of other X-ray selected BL Lac objects. The extended image, when combined with estimates of the linear size of an underlying galaxy, implies both visible and X-ray luminosities consistent with this hypothesis. In a stellar interpretation, the angular extension would require attributing yet another unique feature to the object. The interpretation of the stellar absorption spectrum as misidentification of the object at the telescope is supported. Two candidates for that unrelated stellar object, which are also the next closest bright visible objects to the X-ray source are proposed. It is predicted that the late type absorption spectrum will never again be seen in H0323+022.

Margon, B.↗
NASA NTRS1992

Low energy gamma ray emission from the Cygnus OB2 association

According to our newly developed model of gamma-ray emission from chaotic early-type stellar winds, we predict the combined gamma-ray flux from the circumstellar winds of many very luminous early-type stars in the Cyg OB2 association can be detectable by the Energetic Gamma Ray Experiment Telescope (EGRET) (and maybe also by OSSE) on CGRO. Due to different radiation mechanisms, the gamma-ray spectrum from stellar winds can be quite different from that of CYG X-3; this spectral difference and the time-variation of Cyg X-3 flux will help to distinguish the gamma-ray components from different sources in this small region, which is spatially unresolvable by CGRO.

Chen, Wan↗