At what energy do extragalactic cosmic rays take over from Galactic ones? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
At what energy do extragalactic cosmic rays take over from Galactic ones?
Plain · changed
Revision 1: Below some energy cosmic rays come from our own galaxy and above it from other galaxies; whether the handover happens near $1e17\,\mathrm{eV}$ or near $5e18\,\mathrm{eV}$ (the ankle, where the spectrum flattens) is unsettled.
Revision 2: Below some energy cosmic rays come from our own galaxy and above it from other galaxies; whether the handover happens near $10^{17}\,\mathrm{eV}$ or near $5 \times 10^{18}\,\mathrm{eV}$ (the ankle, where the spectrum flattens) is unsettled.
Precise · changed · core
Revision 1: Determine the energy at which the extragalactic flux exceeds the Galactic flux, using the iron knee near $8e16\,\mathrm{eV}$, the second knee near $1e17\text{ to }3e17\,\mathrm{eV}$, the ankle near $5e18\,\mathrm{eV}$, the energy dependence of the mean shower depth $X_{\mathrm{max}}$ and its spread (lightest composition near $2e18\,\mathrm{eV}$), and the change of the dipole direction from near the Galactic center below $1e18\,\mathrm{eV}$ to away from it above $8e18\,\mathrm{eV}$. Answer: the transition energy and the Galactic component spectrum, including whether a second Galactic population beyond the knee sources is required.
Revision 2: Determine the energy at which the extragalactic flux exceeds the Galactic flux, using the iron knee near $8 \times 10^{16}\,\mathrm{eV}$, the second knee near $10^{17}\text{ to }3 \times 10^{17}\,\mathrm{eV}$, the ankle near $5 \times 10^{18}\,\mathrm{eV}$, the energy dependence of the mean shower depth $X_{\max}$ and its spread (lightest composition near $2 \times 10^{18}\,\mathrm{eV}$), and the change of the dipole direction from near the Galactic center below $10^{18}\,\mathrm{eV}$ to away from it above $8 \times 10^{18}\,\mathrm{eV}$. Answer: the transition energy and the Galactic component spectrum, including whether a second Galactic population beyond the knee sources is required.
Settled by · changed · core
Revision 1: Mass-resolved spectra and anisotropies from $1e16 \text{ to } 1e19\,\mathrm{eV}$ with overlapping detectors, fit by a two-population model with propagation.
Revision 2: Mass-resolved spectra and anisotropies from $10^{16} \text{ to } 10^{19}\,\mathrm{eV}$ with overlapping detectors, fit by a two-population model with propagation.
Kind
well-posed
Answer type
value
References
(empty)
Literature status
contested
Status note
(empty)
Posed since
(empty)

Decisions