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Riegler, G.

Publications and source records attributed to Riegler, G..

9 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

The X-ray superbubble in Cygnus

It is shown that Cyg X-6 and Cyg X-7 are part of a large X-ray ring, 13 degrees in diameter. At a distance of 2 kpc, this X-ray source lies behind the Great Rift of Cygnus, and as such has radiation from its central region absorbed. The diameter of the emitting region is 450 pc. The X-ray source is associated with a ring of elongated H-alpha filaments which enclose the Cygnus X radio source. At the center of this region lies the highly luminous Cygnus OB2 association.

Cash, W.↗
NASA NTRS1979

The cosmic X-ray experiment aboard HEAO-1

The cosmic X-ray experiment aboard the HEAO-1 observatory is described, The instrument consists of six gas proportional counters of three types nominally covering the energy ranges of 0.15 keV, 1.2-20 keV, and 2.5-60 keV. The two low energy detectors have about 400 sq cm open area each while the four others have about 800 sq cm each. A novel feature of this experiment is the dual field of view collimators that allow the unambiguous determination of instrument internal background and diffuse X-ray brightness. Instrument characteristics and early performance are discussed.

Rothschild, R.↗
NASA NTRS1979

HEAO-1 - Low energy X-ray observations of clusters of galaxies

Results are reported for HEAO 1 low-energy X-ray observations of the Perseus and Virgo clusters of galaxies. The best-fit spectrum for the Perseus cluster indicates thermal bremsstrahlung from a plasma at a temperature of 20 + or - 10 million K, with an absorbing hydrogen column of 2 + or - 1 x 10 to the 21st per sq cm. The best-fit thermal-bremsstrahlung model for the Virgo cluster is obtained for a line centered at 1.15 keV, which is the expected position of the iron line complex at a temperature of 40 million K. An iron abundance of 3.1 (+7, -2.3) x 10 to the -5th relative to hydrogen is determined. This abundance is shown to be within a factor of about 3 of the 'cosmic' value.

Lea, S. M.↗
NASA NTRS1978

The soft X-ray spectrum of Capella - Discovery of intense line emission

A soft X-ray spectrum of Capella has been obtained with the HEAO 1 satellite. Only models which include intense line emission at 0.85 keV can adequately explain the data. The spectrum is consistent with emission from an isothermal solar-abundance plasma with a temperature of 10.5 million (+ or - 2.8 million) K. It is also consistent with a blend of temperatures between 4 and 20 million K. The intensity of the X-ray emission is constant over 2 days and similar to the intensity observed by ANS.

Cash, W.↗