The production of {sup 44}Ti and {sup 60}Co in supernovae

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Astrophysical Journal

DOI:https://doi.org/10.1086/177323· OSTI ID:288886

Timmes, F X ^[1]; Woosley, S E ^[2]; Hartmann, D H ^[3]; Hoffman, R D ^[2]

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1. Laboratory for Astrophysics and Space Research, University of Chicago, Chicago, Illinois 60637 (United States)
2. University of California Observatories/Lick Observatory, Board of Studies in Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, California 95064 (United States)
3. Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634 (United States)

The production of the radioactive isotopes {sup 44}Ti and {sup 60}Co in all types of supernovae is examined and compared to observational constraints including Galactic {gamma}-ray surveys, measurements of the diffuse 511 keV radiation, {gamma}-ray observations of Cas A, the late-time light curve of SN 1987A, and isotopic anomalies found in silicon carbide grains in meteorites. The revised line flux from {sup 44}Ti decay in the Cas A supernova remnant reported by COMPTEL on the {ital Compton Gamma Ray Observatory} is near the upper bound expected from our models. The necessary concurrent ejection of {sup 56}Ni would also imply that Cas A was a brighter supernova than previously thought unless extinction in the intervening matter was very large. Thus, the reported amount of {sup 44}Ti in Cas A provides very interesting constraints on both the supernova environment and its mechanism. The abundances of {sup 44}Ti and {sup 60}Co ejected by Type II supernovae are such that gamma-radiation from {sup 44}Ti decay SN 1987A could be detected by a future generation of gamma-ray telescopes, and that the decay of {sup 60}Co might provide an interesting contribution to the late-time light curve of SN 1987A and other core collapse supernovae. To produce the solar {sup 44}Ca abundance and satisfy all observational constraints, nature may prefer at least the occasional explosion of sub-Chandrasekhar mass white dwarfs as Type Ia supernovae. Depending on the escape fraction of positrons due to {sup 56}Co made in all kinds of Type Ia supernovae, a significant fraction of the steady state diffuse 511 keV emission may arise from the annihilation of positrons produced during the decay of {sup 44}Ti to {sup 44}Ca. The Ca and Ti isotopic anomalies in presolar grains confirm the production of {sup 44}Ti in supernovae and that extensive mixing between zones has occurred, but a quantitative model for this mixing is presently lacking. {copyright} {ital 1996 The American Astronomical Society.}

• OSTI ID: 288886
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 464; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COBALT 60
COSMIC GAMMA SOURCES
ELEMENT ABUNDANCE
GAMMA SPECTRA
MATHEMATICAL MODELS
MIXING
NUCLEOSYNTHESIS
STAR EVOLUTION
SUPERNOVAE
TITANIUM 44
WHITE DWARF STARS