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Related papers: Massive-Star Nucleosynthesis and INTEGRAL

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The center of our Galaxy is a known strong source of electron-positron 511-keV annihilation radiation. Thus far, however, there have been no reliable detections of annihilation radiation outside of the central radian of our Galaxy. One of…

We perform multi-dimensional, time-dependent radiation transfer simulations for hard X-ray and gamma-ray emissions, following radioactive decays of 56Ni and 56Co, for two-dimensional delayed detonation models of Type Ia supernovae (SNe Ia).…

High Energy Astrophysical Phenomena · Physics 2015-06-11 K. Maeda , Y. Terada , D. Kasen , F. K. Roepke , A. Bamba , R. Diehl , K. Nomoto , M. Kromer , I. R. Seitenzahl , H. Yamaguchi , T. Tamagawa , W. Hillebrandt

Radioactive components of the interstellar medium provide an entirely-different and new aspect to the studies of the interstellar medium. Injected from sources of nucleosynthesis, unstable nuclei decay along their trajectories. Measurements…

High Energy Astrophysical Phenomena · Physics 2021-12-10 Roland Diehl

The $^{23}$Na($\alpha,p$)$^{26}$Mg reaction has been identified as having a significant impact on the nucleosynthesis of several nuclei between Ne and Ti in type-Ia supernovae, and of $^{23}$Na and $^{26}$Al in massive stars. The reaction…

We have developed a new diagnostic tool for the study of gamma-ray emission lines from radioactive isotopes (such as 26Al and 60Fe in conjunction with other multi-wavelength observables of Galactic clusters, associations, and alike objects.…

Astrophysics · Physics 2007-05-23 M. Cervino , J. Knodlseder , D. Schaerer , P. von Ballmoos , G. Meynet

Massive stars and their supernovae are prominent sources of radioactive isotopes, the observations of which thus can help to improve our astrophysical models of those. Our understanding of stellar evolution and the final explosive endpoints…

High Energy Astrophysical Phenomena · Physics 2010-08-13 Friedrich-Karl Thielemann , Raphael Hirschi , Matthias Liebendörfer , Roland Diehl

The cosmic production of the short-lived radioactive nuclide 26Al is crucial for our understanding of the evolution of stars and galaxies. However, simulations of the stellar sites producing 26Al are still weakened by significant nuclear…

The Cygnus region harbours a huge complex of massive stars at a distance of 1.0-2.0kpc from us. About 170 O stars are distributed over several OB associations, among which the Cyg OB2 cluster is by far the largest with about 100-120 O…

High Energy Astrophysical Phenomena · Physics 2010-01-12 Pierrick Martin , Jürgen Knödlseder , Roland Diehl , Georges Meynet

50% of the heavy element abundances are produced via slow neutron capture reactions in different stellar scenarios. The underlying nucleosynthesis models need the input of neutron capture cross sections. One of the fundamental signatures…

The 340-year old supernova remnant Cassiopeia A at 3.4 kpc distance is the best-studied young core-collapse supernova remnant. Nucleosynthesis yields in radioactive isotopes have been studied with different methods, in particular for…

High Energy Astrophysical Phenomena · Physics 2015-07-22 Thomas Siegert , Roland Diehl , Martin G. H. Krause , Jochen Greiner

The INTEGRAL satellite has been observing the gamma-ray sky for 15 years and has detected over 900 X-ray sources of various nature. However, more than 200 of these sources still lack precise identification. Our goal is to reveal the nature…

High Energy Astrophysical Phenomena · Physics 2018-10-31 Francis Fortin , Sylvain Chaty , Alexis Coleiro , John Tomsick , Christian Nitschelm

We evaluate two dominant nuclear reaction rates and their uncertainties that affect 44Ti production in explosive nucleosynthesis. Experimentally we develop thick-target yields for the 40Ca(alpha,gamma)44Ti reaction at E(alpha) = 4.13, 4.54,…

The measurement of gamma rays at MeV energies from cosmic radioactivities is one of the key tools for nuclear astrophysics, in its study of nuclear reactions and how they shape objects such as massive stars and supernova explosions.…

High Energy Astrophysical Phenomena · Physics 2017-03-29 Roland Diehl

The mixing of ejecta from young stars into the interstellar medium is an important process in the interplay between star formation and galaxy evolution. A unique window into these processes is provided by the radioactive isotopes $^{26}$Al,…

Astrophysics of Galaxies · Physics 2015-06-03 R. Voss

INTEGRAL/SPI is a space-based coded mask telescope featuring a 19-element Germanium detector array for high-resolution gamma-ray spectroscopy, encapsulated in a scintillation detector assembly that provide a veto for background from charged…

Gamma-ray line observations provide a versatile tool for studies of nucleosynthesis processes and supernova physics. In particular, the observation of radioactive species in the interstellar medium probes recent nucleosynthesis activity on…

Astrophysics · Physics 2009-12-30 Jurgen Knodlseder

The measurement of gamma-ray lines from the decay chain of 56Ni provides unique information about the explosion in supernovae. The 56Ni freshly-produced in the supernova powers the optical light curve, as it emits gamma-rays upon its…

The nucleosynthesis in the first massive stars may be constrained by observing the surface composition of long-lived very iron-poor stars born around 10 billion years ago from material enriched by their ejecta. Many interesting clues on…

Solar and Stellar Astrophysics · Physics 2016-02-15 Arthur Choplin , Georges Meynet , Andre Maeder , Raphael Hirschi , Cristina Chiappini

The production of $^{60}$Fe is crucial for nucleosynthesis in massive stars and supernovae. In this work, by using the microscopic EP+IPM (exact pairing plus the independent-particle model) for the nuclear level density (NLD) and extended…

The shape of the gamma-ray line from radioactive 26Al, at 1808.7 keV energy in the frame of the decaying isotope, is determined by its kinematics when it decays, typically 10^6 y after its ejection into the interstellar medium from its…

Astrophysics · Physics 2007-05-23 K. Kretschmer , R. Diehl , D. H. Hartmann
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