Detection of γ-ray lines from interstellar $\mathsf{^{60}}$Fe  by the
high resolution spectrometer SPI

Harris, Michael J.; Knödlseder, J.; Jean, P.; Cisana, E.; Diehl, R.; Lichti, G.; Roques, J. P.; Schanne, S.; Weidenspointner, G.

doi:10.1051/0004-6361:200500093

Cited by 77 publications

(91 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With our analysis, the 60 Fe mean flux in the inner Galaxy is about 4× 10 −5 photons cm −2 s −1 , leading to a 60 Fe to 26 Al ratio between 0.12 and 0.15. Considering the numerous uncertainties still affecting these models, this results confirms those reported by [28,34], and can be used to reject some hypotheses, but not yet to definitively discriminate the good ones. We performed a direct imaging reconstruction of the 26 Al emission by using maximum-entropy method.…”

Section: Discussionsupporting

confidence: 79%

Diffuse emission study with INTEGRAL/SPI: Results after 10 years of observations

Bouchet¹

2015

Proceedings of 10th INTEGRAL Workshop: A Synergistic View of the High-Energy Sky — PoS(Integral2014)

View full text Add to dashboard Cite

The SPI spectrometer is currently the most sensitive instrument operating in the MeV energy region. We take advantage of the long sky exposure duration (∼2×10 8 s) obtained between 2003 and 2013 to map the large scale structure morphologies of the Galaxy. We emphasis the 26 Al radioactive line emission. So far, only COMPTEL data have allowed to perform its detailed morphology study. The INTEGRAL mission is an opportunity to provide additional information on this topic. We developed a maximum entropy code to attempt to reconstruct the image of the sky. The preliminary map shows that the emission comes mainly from the inner Galaxy region, and hence supports the chief findings of COMPTEL. The map also indicates more localized potential sites of emission.

show abstract

Section: Discussionsupporting

confidence: 79%

Diffuse emission study with INTEGRAL/SPI: Results after 10 years of observations

Bouchet¹

2015

Proceedings of 10th INTEGRAL Workshop: A Synergistic View of the High-Energy Sky — PoS(Integral2014)

View full text Add to dashboard Cite

show abstract

“…RHESSI has reported the first detection of 60 Fe gamma-ray lines, and gave a flux ratio 0.16 ± 0.13 for two-year data (Smith, 2004a). The first year data of SPI gave a flux ratio 0.11 ± 0.07 (Harris et al, 2005), and the present analysis of the 3-year SPI data finds a flux ratio 0.148 ± 0.06 (Wang et al 2007). …”

Section: Diffuse 60 Fe Emission Of the Galaxysupporting

confidence: 59%

“…The analysis of the first year of data from the SPI data resulted in a similarly marginally-significant detection of these γ-ray lines from 60 Fe (∼ 3σ, Harris et al 2005), with an average line flux of (3.7 ± 1.1) × 10 −5 ph cm −2 s −1 from the inner Galaxy. With more than 3-year SPI data, we detected the diffuse 60 Fe emission in the Galaxy with a significance level of ∼ 5σ by superposing two gamma-ray lines at 1173 keV and 1332 keV (Fig.…”

Section: Diffuse 60 Fe Emission Of the Galaxymentioning

confidence: 93%

Diffuse emission of 26Al and 60Fe in the Galaxy

Wang¹

2012

Astrophysics

View full text Add to dashboard Cite

Cosmic gamma-ray line signals are very weak, and the gamma-ray photons are absorbed by the atmosphere. The detection of Galactic radioactivity must be based on the gamma-ray detectors aboard balloons and spacecrafts. The first gamma-ray line observations were from OSO-3, OSO-7 in 1960's, which revealed the strong 2.223 MeV line from solar flares (Brandt, 1969). This line results from the formation of deuterium via the union of a neutron and proton; in a solar flare the neutrons appear as secondaries from interactions of high-energy

show abstract

“…Model predictions of 60 Fe yields range from insignificant to amounts that rival 26 Al amounts, but uncertainties are large for these shell burning stages. Gamma rays from 60 Fe decays in the Galaxy were seen with the RHESSI [73] and the INTEGRAL [74,75] spacecraft instruments, from the inner ridge of our Galaxy. The gamma ray brightness of 60 Fe is however much smaller than that of 26 Al (the ratio is 15% (±5%).…”

Section: Al and 60 Fe From Cumulative Nucleosynthesismentioning

confidence: 99%

About cosmic gamma ray lines

Diehl

2017

AIP Conference Proceedings

View full text Add to dashboard Cite

Abstract. Gamma ray lines from cosmic sources convey the action of nuclear reactions in cosmic sites and their impacts on astrophysical objects. Gamma rays at characteristic energies result from nuclear transitions following radioactive decays or highenergy collisions with excitation of nuclei. The gamma-ray line from the annihilation of positrons at 511 keV falls into the same energy window, although of different origin. We present here the concepts of cosmic gamma ray spectrometry and the corresponding instruments and missions, followed by a discussion of recent results and the challenges and open issues for the future. Among the lessons learned are the diffuse radioactive afterglow of massive-star nucleosynthesis in 26 Al and 60 Fe gamma rays, which is now being exploited towards the cycle of matter driven by massive stars and their supernovae; large interstellar cavities and superbubbles have been recognised to be of key importance here. Also, constraints on the complex processes making stars explode as either thermonuclear or core-collapse supernovae are being illuminated by gamma-ray lines, in this case from shortlived radioactivities from 56 Ni and 44 Ti decays. In particular, the three-dimensionality and asphericities that have recently been recognised as important are enlightened in different ways through such gamma-ray line spectroscopy. Finally, the distribution of positron annihilation gamma ray emission with its puzzling bulge-dominated intensity disctribution is measured through spatially-resolved spectra, which indicate that annihilation conditions may differ in different parts of our Galaxy. But it is now understood that a variety of sources may feed positrons into the interstellar medium, and their characteristics largely get lost during slowing down and propagation of positrons before annihilation; a recent microquasar flare was caught as an opportunity to see positrons annihilate at a source.

show abstract

Detection of γ-ray lines from interstellar $\mathsf{^{60}}$Fe by the high resolution spectrometer SPI

Cited by 77 publications

References 8 publications

Diffuse emission study with INTEGRAL/SPI: Results after 10 years of observations

Diffuse emission study with INTEGRAL/SPI: Results after 10 years of observations

Diffuse emission of 26Al and 60Fe in the Galaxy

About cosmic gamma ray lines

Contact Info

Product

Resources

About