Reply [to “Discussion of paper by R. C. Haymes, S. W. Glenn, G. J. Fishman, and F. R. Harnden, Jr., ‘Low-energy gamma radiation in the atmosphere at midlatitudes’”]

Haymes, R. C.; Glenn, S. W.; Fishman, G. J.; Harnden, F. R.

doi:10.1029/ja075i004p00873

Cited by 11 publications

(14 citation statements)

References 5 publications

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“…A variation of intensity by a factor of two in the hard X-ray range was found by Haymes and Harnden (1970) (1972) found oscillatory behaviour in the X-ray emission of Cyg X-1 lasting typically several seconds with the frequency drifting within a few seconds repeatedly. A sporadic periodicity in the 30-200 KeV range has also been observed by Frontera and Fuligni (1975).…”

Section: Iii31 X-ray Observationsmentioning

confidence: 99%

Celestial binary X-ray sources

Apparao

Chitre

1976

Space Sci Rev

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Section: Iii31 X-ray Observationsmentioning

confidence: 99%

Celestial binary X-ray sources

Apparao

Chitre

1976

Space Sci Rev

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“…This emission was first seen in a series of balloon observations with low-resolution Nal detectors starting in 1970 (Johnson, Harnden and Haymes 1972, Johnson and Haymes 1973, Haymes et al 1975. But it was not until 1977 that the annihilation line energy of 0.511 MeV was clearly identified with high-resolution Ge detectors flown by Leventhal, MacCallum and Stang (1978).…”

Section: The Observationsmentioning

confidence: 99%

Positron-Electron Annihilation Radiation from the Galactic Center

Ramaty

Lingenfelter

1983

Highlights astron.

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“…The first GBH candidate, Cygnus X-1, was discovered by a rocket experiment in the 1960s [1]. Balloon-borne experiments led to characterizations of its spectral shape [2,3], while space-based experiments discovered its flux state transitions [4,5,6], and later, its spectral state transitions [7]. Early gamma-ray observations showed that Cygnus X-1 is variable at higher energies [8,9,10], with episodic emission observed up to > 1 MeV [11,12].…”

Section: Introductionmentioning

confidence: 99%

Low Energy Gamma-Ray Emission from Galactic Black Holes

Case¹,

Cherry²,

Ling³

et al. 2008

AIP Conference Proceedings

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Abstract. X-ray observations of Galactic black holes (GBHs) such as Cygnus X-1 have greatly advanced the understanding of these objects. However, the vast majority of the observations have been restricted to energies below ∼ 200 keV. The Compton Gamma-Ray Observatory (CGRO) allowed for the first time simultaneous observations at energies from ∼ 25 keV up to > 1 GeV. In particular, the BATSE experiment aboard CGRO was able to monitor low-energy gamma-ray emission from Cygnus X-1, as well as other GBHs, nearly continuously over a nine year period. Using the Enhanced BATSE Occultation Package (EBOP), light curves and spectra in the energy range 25 − 2000 keV have been obtained for six GBHs. Based on the spectra when the GBHs were in a high gamma-ray flux state, it is suggested that at least two different classes of GBHs exist. The first is characterized by a Comptonization spectrum below ∼ 200 keV followed by a soft power law excess as exhibited by Cygnus X-1, GRO J0422+32, GRO J1719-24, and GX 339-4. The second class is characterized by simple power law spectrum in the full 25 − 2000 keV range, with no evidence for a Comptonization component, as exhibited by GRO J1655-40 and GRS 1915+105.Gamma-ray observations can serve as an important diagnostic in studying the physical processes around GBHs. More sensitive observations in the future at energies > 250 keV will help answer questions regarding issues such as the nonthermal electron distribution, state transitions, and the connection to jets.

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Reply [to “Discussion of paper by R. C. Haymes, S. W. Glenn, G. J. Fishman, and F. R. Harnden, Jr., ‘Low-energy gamma radiation in the atmosphere at midlatitudes’”]

Cited by 11 publications

References 5 publications

Celestial binary X-ray sources

Celestial binary X-ray sources

Positron-Electron Annihilation Radiation from the Galactic Center

Low Energy Gamma-Ray Emission from Galactic Black Holes

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