OB Associations, Wolf-Rayet Stars, and the Origin of Galactic Cosmic Rays
arXiv:0707.4645 · doi:10.1007/s11214-007-9195-1
Abstract
We have measured the isotopic abundances of neon and a number of other species in the galactic cosmic rays (GCRs) using the Cosmic Ray Isotope Spectrometer (CRIS) aboard the ACE spacecraft. Our data are compared to recent results from two-component Wolf-Rayet (WR) models. The three largest deviations of galactic cosmic ray isotope ratios from solar-system ratios predicted by these models, 12C/16O, 22Ne/20Ne, and 58Fe/56Fe, are very close to those observed. All of the isotopic ratios that we have measured are consistent with a GCR source consisting of ~20% of WR material mixed with ~80% material with solar-system composition. Since WR stars are evolutionary products of OB stars, and most OB stars exist in OB associations that form superbubbles, the good agreement of our data with WR models suggests that OB associations within superbubbles are the likely source of at least a substantial fraction of GCRs. In previous work it has been shown that the primary 59Ni (which decays only by electron-capture) in GCRs has decayed, indicating a time interval between nucleosynthesis and acceleration of >10^5 yr.In this paper we suggest a scenario that should allow much of the 59Ni to decay in the OB association environment and conclude that the hypothesis of the OB association origin of cosmic rays appears to be viable.
arXiv comment13 pages, 3 figures, To be published by Space Science Reviews, 2007
References in corpus (15)
- How Massive Single Stars End their Life
- The Chemical Compositions of Galactic Disk F and G Dwarfs
- The Evolution of the Elemental Abundances in the Gas and Dust Phases of the Galaxy
- Stellar evolution with rotation XI: Wolf-Rayet star populations at different metallicities
- Stellar evolution with rotation X: Wolf-Rayet star populations at solar metallicity
- Galactic Cosmic Rays from Supernova Remnants: II Shock Acceleration of Gas and Dust
- The Origin of Cosmic Dust
- Galactic Cosmic Rays from Supernova Remnants (I) - a Cosmic Ray Composition controlled by Volatility and Mass-to-Charge Ratio
- Galactic Metallicity Gradients Derived from a Sample of OB Stars
- Superbubbles and Energetic Particles in the Galaxy. I: Collective effects of particle acceleration
- Quantitative analysis of WC stars: Constraints on neon abundances from ISO/SWS spectroscopy
- Cosmic ray neon, Wolf-Rayet stars, and the superbubble origin of galactic cosmic rays
- Constraints on gamma-ray burst and supernova progenitors through circumstellar absorption lines
- The production of short-lived radionuclides by new non-rotating and rotating Wolf-Rayet model stars
- Explosive Nucleosynthesis from GRB and Hypernova Progenitors: Direct Collapse versus Fallback
Cited by in corpus (15)
- Discrepant hardening observed in cosmic-ray elemental spectra
- Observational signatures of particle acceleration in supernova remnants
- Impact of low-energy cosmic rays on star formation
- Inference of the Local Interstellar Spectra of Cosmic Ray Nuclei Z<=28 with the GalProp-HelMod Framework
- Beyond the myth of the supernova-remnant origin of cosmic rays
- Ultrahard spectra of PeV neutrinos from supernovae in compact star clusters
- Cosmic ray acceleration parameters from multi-wavelength observations. The case of SN 1006
- Cosmic rays in galactic and extragalactic magnetic fields
- Markov chain Monte Carlo analyses of the flux ratios of B, Be and Li with the DRAGON2 code
- A Cosmic Ray Resolution to the Superbubble Energy-Crisis
- Supernova explosions of massive stars and cosmic rays
- Pulsar Wind Nebulae and Cosmic Rays: A Bedtime Story
- The Local Bubble in the interstellar medium and the origin of the low energy cosmic rays
- The interaction of multiple stellar winds in stellar clusters: potential flow
- Radio study of HESS J1857+026. Gamma-rays from a superbubble?