Detection of 511 keV positron annihilation radiation from the galactic center direction

Leventhal, M.; MacCallum, C. J.; Stang, P. D.

doi:10.1086/182782

Cited by 275 publications

(156 citation statements)

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“…This transient line emission was observed on 13-14 October 1990 with the imaging gamma ray spectrometer SIGMA. Similar line emission from an unidentified source or sources in the direction of the Galactic center was also observed with non imaging Ge detectors flown on balloons in 1977 (Leventhal et al 1978;Leventhal and MacCallum 1980) and 1989 (Smith et al 1993), as well as from another unidentified source 12 • away from the Galactic center with HEAO-1 (Briggs et al 1995). We discuss these further in §5.…”

Section: Galactic Positron Annihilation Radiationsupporting

confidence: 59%

“…Line emission at both ∼0.48 MeV and ∼0.19 MeV were simultaneously observed with SIGMA from Nova Muscae during its outburst on 20 January 1991 (Goldwurm et al 1992). Similar features at 0.496 MeV and ∼0.17 MeV and at ∼0.40 MeV and ∼0.16 MeV were observed with balloon-borne Ge spectrometers from an unidentified source, or sources, in the Galactic center region in 1977 (Leventhal and MacCallum 1980(Smith et al 1993, respectively. Only the higher energy line at ∼0.40 MeV was observed with SIGMA from 1E1740.7-2942 during an outburst on 13-14 October 1990(Bouchet et al 1991Gilfanov et al 1994), and at ∼ 0.46 MeV with HEAO-1 from another source, possibly the low mass X-ray binary 1H1822-371, about 12 • away from the Galactic center (Briggs et al 1995).…”

Section: Line Features From Black Hole Candidatessupporting

confidence: 57%

“…The annihilation radiation can also be redshifted, leading to line emission below 0.511 MeV, if the annihilation site is sufficiently close to a neutron star or black hole. A narrow line at precisely 0.511 MeV (with line centroid error of only a few tenths of keV and width less than 3 keV) has been observed on many occasions with Ge detectors from the direction of the Galactic center (Leventhal, MacCallum, and Stang 1978;Smith et al 1993). This line has also been observed with the OSSE instrument on CGRO (Purcell et al 1993).…”

Section: Introductionmentioning

confidence: 83%

“…Ramaty, Borner and Cohen (1973) suggested that the observed line was due to gravitationally redshifted annihilation radiation produced on the surfaces of neutron stars, while Leventhal (1973) pointed out that the convolution of a spectrum consisting of the 0.511 MeV line and the accompanying positronium continuum with the response function of a detector with poor energy resolution would lead to the apparent redshift. It was not until 1977, that the line energy was accurately determined with a Ge spectrometer (Leventhal, MacCallum, and Stang 1978). The observed line center energy, 510.7±0.5 keV, clearly established that the radiation was due to the annihilation of positrons.…”

Section: Galactic Positron Annihilation Radiationmentioning

confidence: 96%

See 3 more Smart Citations

Astrophysical Gamma Ray Emission Lines

Ramaty¹,

Lingenfelter²

1995

The Analysis of Emission Lines

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We review the wide range of astrophysical observations of gamma ray emission lines and we discuss their implications. We consider line emission from solar flares, the Orion molecular cloud complex, supernovae 1987A and 1991T, the supernova remnants Cas A and Vela, the interstellar medium, the Galactic center region and several Galactic black hole candidates. The observations have important, and often unique, implications on particle acceleration, star formation, processes of nucleosynthesis, Galactic evolution and compact object physics.

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Section: Galactic Positron Annihilation Radiationsupporting

confidence: 59%

Section: Line Features From Black Hole Candidatessupporting

confidence: 57%

Section: Introductionmentioning

confidence: 83%

Section: Galactic Positron Annihilation Radiationmentioning

confidence: 96%

See 2 more Smart Citations

Astrophysical Gamma Ray Emission Lines

Ramaty¹,

Lingenfelter²

1995

The Analysis of Emission Lines

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“…There are other candidate sources of interstellar positrons, such as magnetized and rotating neutron stars and accreting binary systems, which are expected to release electron-positron plasma with much higher energies ( GeV), and dark-matter particle interactions may also plausibly contribute to produce positrons (for a review see [99]). The positron annihilation gamma-ray line was the first cosmic gamma-ray line ever detected, in 1972, with a low-resolution NaI detector instrument [60], and later identified as annihilation line through the Ge detector measurement providing sufficient spectroscopic precision for line identificantion [76].…”

Section: Positron Annihilationmentioning

confidence: 99%

Cosmic Gamma-Ray Spectroscopy

Diehl

2013

Astronomical Review

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Penetrating gamma-rays require complex instrumentation for astronomical spectroscopy measurements of gamma-rays from cosmic sources. Multiple-interaction detectors in space combined with sophisticated postprocessing of detector events on ground have lead to a spectroscopy performance which is now capable to provide new astrophysical insights. Spectral signatures in the MeV regime originate from transitions in the nuclei of atoms (rather than in their electron shell). Nuclear transitions are stimulated by either radioactive decays or high-energy nuclear collisions such as with cosmic rays. Gamma-ray lines have been detected from radioactive isotopes produced in nuclear burning inside stars and supernovae, and from energetic-particle interactions in solar flares. Radioactive-decay gamma-rays from 56 Ni directly reflect the source of supernova light. 44 Ti is produced in core-collapse supernova interiors, and the paucity of corresponding 44 Ti gamma-ray line sources reflects the variety of dynamical conditions herein. 26 Al and 60 Fe are dispersed in interstellar space from massive-star nucleosynthesis over millions of years. Gamma-rays from their decay are measured in detail by gamma-ray telescopes, astrophysical interpretations reach from massive-star interiors to dynamical processes in the interstellar medium. Nuclear de-excitation gamma-ray lines have been found in solar-flare events, and convey information about energetic-particle production in these events, and their interaction in the solar atmosphere. The annihilation of positrons leads to another type of cosmic gamma-ray source. The characteristic annihilation gamma-rays at 511 keV have been measured long ago in solar flares, and now throughout the interstellar medium of our Milky Way galaxy. But now a puzzle has appeared, as a surprising predominance of the central bulge region was determined. This requires either new positron sources or transport processes not yet known to us. In this paper we discuss instrumentation and data processing for cosmic gamma-ray spectroscopy, and the astrophysical issues and insights from these measurements.

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Abelian dark matter models for 511 keV γ rays and direct detection

Cline

Frey

2012

Annalen der Physik

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We construct a simple U(1) hidden sector model of metastable dark matter that could explain excess 511 keV gamma rays from the galactic center as observed by INTEGRAL, through inelastic scattering of dark matter followed by its decay. Although the model is highly constrained, it naturally accommodates dark matter with mass and cross section in the range suggested by the CoGeNT and CRESST experiments. The dark gauge boson that mediates the interactions with standard model matter has a mass of several hundred MeV, and might be discovered by heavy photon detection experiments, including APEX, MAMI and HPS.

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Detection of 511 keV positron annihilation radiation from the galactic center direction

Cited by 275 publications

References 0 publications

Astrophysical Gamma Ray Emission Lines

Astrophysical Gamma Ray Emission Lines

Cosmic Gamma-Ray Spectroscopy

Abelian dark matter models for 511 keV γ rays and direct detection

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