scholarly journals 60Fe and Massive Stars

2008 ◽  
Vol 4 (S252) ◽  
pp. 333-338
Author(s):  
Wei Wang
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Massive Stars ◽  
Radioactive Decay ◽  
Line Emission ◽  
Flux Ratio ◽  
Core Collapse ◽  
Analysis Method ◽  
Line Flux ◽  
Average Flux

AbstractGamma-ray line emission from radioactive decay of 60Fe provides constraints on nucleosynthesis in massive stars and supernovae. We detect the γ-ray lines from 60Fe decay at 1173 and 1333 keV using three years of data from the spectrometer SPI on board INTEGRAL. The average flux per line is (4.4 ± 0.9) × 10−5 ph cm−2 s−1 rad−1 for the inner Galaxy region. Deriving the Galactic 26Al gamma-ray line flux with using the same set of observations and analysis method, we determine the flux ratio of 60Fe/26Al gamma-rays as 0.15 ± 0.05. We discuss the implications of these results for the widely-held hypothesis that 60Fe is synthesized in core-collapse supernovae, and also for the closely-related question of the precise origin of 26Al in massive stars.

scholarly journals Gamma-Ray Spectral Observations with Yohkoh

1994 ◽  
Vol 142 ◽  
pp. 639-643 ◽  
Author(s):  
M. Yoshimori ◽  
K. Suga ◽  
K. Morimoto ◽  
T. Hiraoka ◽  
J. Sato ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Temporal Evolution ◽  
Spectral Feature ◽  
Line Emission ◽  
Flux Ratio ◽  
X Rays ◽  
X Ray ◽  
Angle Scattering ◽  
Positron Production

AbstractWe present gamma-ray observations of the 1991 October 27, November 15, and December 3 flares with the Yohkoh gamma-ray and hard X-ray spectrometers. The October 27 flare (X6.1 /3B) shows significant gamma-ray line emission, and the temporal evolution of the gamma-ray line-to-bremsstrahlung flux ratio indicates that protons and electrons were complicatedly accelerated during flare. The December 3 flare (X2.0/2B) shows a strong bremsstrahlung continuum extending to 10 MeV and indicates that electrons were preferentially accelerated to 10 MeV. A line feature at 420 keV was observed from the November 15 flare (X1.0/3B). This is most likely due to a compound of redshifted nuclear deexcitation lines of Be (429 keV) and Li (478 keV) resulting from He-He reactions. The spectral feature indicates that the accelerated He nuclei suffer strong pitch-angle scattering in the corona and form a downward-peaked distribution. Furthermore, the November 15 flare exhibits evidence of positron annihilation line at 511 keV. The positron production processes and the electron density of the annihilation region are discussed on the basis of the temporal characteristics of 511 keV line emission.Subject headings: line: identification — Sun: flares — Sun: X-rays, gamma-rays

scholarly journals 60Fe in core-collapse supernovae and prospects for X-ray and gamma-ray detection in supernova remnants

2019 ◽  
Vol 485 (3) ◽  
pp. 4287-4310 ◽  
Author(s):  
Samuel W Jones ◽  
Heiko Möller ◽  
Chris L Fryer ◽  
Christopher J Fontes ◽  
Reto Trappitsch ◽  
...  
Keyword(s):  
Cross Section ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
Flux Ratio ◽  
Core Collapse ◽  
Line Broadening ◽  
X Ray ◽  
Core Collapse Supernova ◽  
Structure Line ◽  
Solar Metallicity

Abstract We investigate 60Fe in massive stars and core-collapse supernovae focussing on uncertainties that influence its production in 15, 20, and 25 M$\odot$ stars at solar metallicity. We find that the 60Fe yield is a monotonic increasing function of the uncertain 59Fe(n, γ)60Fe cross-section and that a factor of 10 reduction in the reaction rate results in a factor of 8–10 reduction in the 60Fe yield, while a factor of 10 increase in the rate increases the yield by a factor of 4–7. We find that none of the 189 simulations we have performed are consistent with a core-collapse supernova triggering the formation of the Solar system, and that only models using 59Fe(n, γ)60Fe cross-section that is less than or equal to that from NON-SMOKER can reproduce the observed 60Fe/26Al line flux ratio in the diffuse interstellar medium. We examine the prospects of detecting old core-collapse supernova remnants (SNRs) in the Milky Way from their gamma-ray emission from the decay of 60Fe, finding that the next generation of gamma-ray missions could be able to discover up to ∼100 such old SNRs as well as measure the 60Fe yields of a handful of known Galactic SNRs. We also predict the X-ray spectrum that is produced by atomic transitions in 60Co following its ionization by internal conversion and give theoretical X-ray line fluxes as a function of remnant age as well as the Doppler and fine-structure line broadening effects. The X-ray emission presents an interesting prospect for addressing the missing SNR problem with future X-ray missions.

scholarly journals What do Gamma Rays tell us about the ISM?: New Insight from the Compton Observatory

1996 ◽  
Vol 169 ◽  
pp. 437-446 ◽  
Author(s):  
Hans Bloemen
Keyword(s):  
Interstellar Medium ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Line Emission ◽  
Cosmic Ray ◽  
Gamma Ray Astronomy ◽  
Early Results ◽  
The Galaxy ◽  
Γ Ray ◽  
Insight Into

Gamma-ray astronomy has become a rich field of research and matured significantly since the launch of NASA's Compton Gamma Ray Observatory in April 1991. Studies of the diffuse γ-ray emission of the Galaxy can now be performed in far more detail and extended into the MeV regime, including both continuum and line emission. These studies provide unique insight into various aspects of the interstellar medium, in particular of the cosmic-ray component. This paper gives a brief review on the diffuse Galactic γ-ray emission and summarizes early results and prospects from the Compton Observatory.

scholarly journals From diffuse extragalactic and galactic gamma-rays to limits on extra dimensions

2019 ◽  
Vol 492 (1) ◽  
pp. L66-L68
Author(s):  
Michel Cassé ◽  
Bruno Mansoulié ◽  
Joseph Silk
Keyword(s):  
Dark Matter ◽  
Gamma Rays ◽  
Extra Dimensions ◽  
Gamma Ray ◽  
Core Collapse ◽  
Planck Mass ◽  
Galactic Emission ◽  
Lower Limits ◽  
Kaluza Klein

ABSTRACT We derive the maximum fraction of energy emitted in the form of massive (Kaluza–Klein) gravitons by core collapse supernovae, and the corresponding minimal extra-dimensional Planck mass M* in the ADD gravity framework at TeV scales. Our constraints arise (a) from the extragalactic gamma-ray background observed by Fermi-LAT after astrophysical sources have been removed and (b) via the residual galactic emission left after astrophysical and potentially dark matter emission have been removed. We focus on a number of extra dimensions 3 and 4, since M* is then in the TeV range, where astrophysical and collider constraints compete. Lower limits on M* are derived in the case (a) of 8.0 and 1.1 TeV for n = 3 and n = 4, respectively, and in the case (b) of 16 and 1.9 TeV. These limits are especially robust and insensitive to the various uncertainties involved.

scholarly journals Properties of gamma-ray decay lines in 3D core-collapse supernova models, with application to SN 1987A and Cas A

2020 ◽  
Vol 494 (2) ◽  
pp. 2471-2497 ◽  
Author(s):  
A Jerkstrand ◽  
A Wongwathanarat ◽  
H-T Janka ◽  
M Gabler ◽  
D Alp ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Radioactive Decay ◽  
Supernova Explosion ◽  
3D Models ◽  
Core Collapse ◽  
Line Profiles ◽  
Sn 1987A ◽  
And Shifts ◽  
Cas A ◽  
Explosive Burning

ABSTRACT Comparison of theoretical line profiles to observations provides important tests for supernova explosion models. We study the shapes of radioactive decay lines predicted by current 3D core-collapse explosion simulations, and compare these to observations of SN 1987A and Cas A. Both the widths and shifts of decay lines vary by several thousand kilometres per second depending on viewing angle. The line profiles can be complex with multiple peaks. By combining observational constraints from 56Co decay lines, 44Ti decay lines, and Fe IR lines, we delineate a picture of the morphology of the explosive burning ashes in SN 1987A. For MZAMS = 15−20 M⊙ progenitors exploding with ∼1.5 × 1051 erg, ejecta structures suitable to reproduce the observations involve a bulk asymmetry of the 56Ni of at least ∼400 km s−1 and a bulk velocity of at least 1500 km s−1. By adding constraints to reproduce the UVOIR bolometric light curve of SN 1987A up to 600 d, an ejecta mass around 14 M⊙ is favoured. We also investigate whether observed decay lines can constrain the neutron star (NS) kick velocity. The model grid provides a constraint VNS > Vredshift, and applying this to SN 1987A gives a NS kick of at least 500 km s−1. For Cas A, our single model provides a satisfactory fit to the NuSTAR observations and reinforces the result that current neutrino-driven core-collapse SN models achieve enough bulk asymmetry in the explosive burning material. Finally, we investigate the internal gamma-ray field and energy deposition, and compare the 3D models to 1D approximations.

scholarly journals Supernovae and Gamma-ray Bursts

2011 ◽  
Vol 7 (S279) ◽  
pp. 75-82
Author(s):  
Paolo A. Mazzali
Keyword(s):  
Black Hole ◽  
Massive Star ◽  
Gamma Ray ◽  
Massive Stars ◽  
Observational Evidence ◽  
Gamma Ray Bursts ◽  
Core Collapse ◽  
Broad Absorption ◽  
X Ray ◽  
Long Duration

AbstractThe properties of the Supernovae discovered in coincidence with long-duration Gamma-ray Bursts and X-Ray Flashes are reviewed, and compared to those of SNe for which GRBs are not observed. The SNe associated with GRBs are of Type Ic, they are brighter than the norm, and show very broad absorption lines in their spectra, indicative of high expansion velocities and hence of large explosion kinetic energies. This points to a massive star origin, and to the birth of a black hole at the time of core collapse. There is strong evidence for gross asymmetries in the SN ejecta. The observational evidence seems to suggest that GRB/SNe are more massive and energetic than XRF/SNe, and come from more massive stars. While for GRB/SNe the collapsar model is favoured, XRF/SNe may host magnetars.

scholarly journals The Supernova/GRB Connection

2005 ◽  
Vol 192 ◽  
pp. 403-410 ◽  
Author(s):  
P. Höflich ◽  
D. Baade ◽  
A. Khokhlov ◽  
L. Wang ◽  
J.C. Wheeler
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Central Region ◽  
Stellar Evolution ◽  
Axial Symmetry ◽  
Energy Deposition ◽  
Gamma Ray ◽  
Massive Stars ◽  
Core Collapse ◽  
Supernova Explosions

SummaryWe discuss the possible connection between supernova explosions (SN) and gamma-ray bursters (GRB) from the perspective of our current understanding of SN physics. Core collapse supernovae (SN) are the final stages of stellar evolution in massive stars during which the central region collapses, forms a neutron star (NS) or black hole, and the outer layers are ejected. Recent explosion scenarios assumed that the ejection is due to energy deposition by neutrinos into the envelope but detailed models do not produce powerful explosions. There is new and mounting evidence for an asphericity and, in particular, for axial symmetry in several supernovae which may be hard to reconcile within the spherical picture. The 3-D signatures are a key to understand core collapse supernovae and the GRB/SN connection. In this paper we study the effects and observational consequences of asymmetric explosions.

scholarly journals Gamma-ray line measurements from supernova explosions

2017 ◽  
Vol 12 (S331) ◽  
pp. 157-163 ◽  
Author(s):  
Roland Diehl
Keyword(s):  
Supernova Remnant ◽  
Gamma Ray ◽  
Radioactive Decay ◽  
Line Emission ◽  
Gamma Ray Spectrometry ◽  
Young Supernova Remnant ◽  
Supernova Explosions ◽  
Cas A ◽  
Integral Data ◽  
Gamma Ray Telescopes

AbstractGamma ray lines are expected to be emitted as part of the afterglow of supernova explosions, because radioactive decay of freshly synthesised nuclei occurs. Significant radioactive gamma ray line emission is expected from56Ni and44Ti decay on time scales of the initial explosion (56Ni, τ ~days) and the young supernova remnant (44Ti,τ ~90 years). Less specific, and rather informative for the supernova population as a whole, are lessons from longer lived isotopes such as26Al and60Fe. From isotopes of elements heavier than iron group elements, any interesting gamma-ray line emission is too faint to be observable. Measurements with space-based gamma-ray telescopes have obtained interesting gamma ray line emissions from two core collapse events, Cas A and SN1987A, and one thermonuclear event, SN2014J. We discuss INTEGRAL data from all above isotopes, including all line and continuum signatures from these two objects, and the surveys for more supernovae, that have been performed by gamma ray spectrometry. Our objective here is to illustrate what can be learned from gamma-ray line emission properties about the explosions and their astrophysics.

scholarly journals The Bright Optical Flash and Afterglow from the Gamma-Ray Burst GRB 130427A

Science ◽  
2013 ◽  
Vol 343 (6166) ◽  
pp. 38-41 ◽  
Author(s):  
W. T. Vestrand ◽  
J. A. Wren ◽  
A. Panaitescu ◽  
P. R. Wozniak ◽  
H. Davis ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Massive Stars ◽  
Close Correlation ◽  
Optical Observations ◽  
X Rays ◽  
Reverse Shock ◽  
Gamma Ray Burst ◽  
Forward Shock ◽  
Gamma Ray Emission

The optical light generated simultaneously with x-rays and gamma rays during a gamma-ray burst (GRB) provides clues about the nature of the explosions that occur as massive stars collapse. We report on the bright optical flash and fading afterglow from powerful burst GRB 130427A. The optical and >100–megaelectron volt (MeV) gamma-ray flux show a close correlation during the first 7000 seconds, which is best explained by reverse shock emission cogenerated in the relativistic burst ejecta as it collides with surrounding material. At later times, optical observations show the emergence of emission generated by a forward shock traversing the circumburst environment. The link between optical afterglow and >100-MeV emission suggests that nearby early peaked afterglows will be the best candidates for studying gamma-ray emission at energies ranging from gigaelectron volts to teraelectron volts.

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