There are two distinct breaks in the cosmic ray (CR) spectrum: the so-called "knee" around 3 × 10 15 eV and the so-called "ankle" around 10 18 eV. Diffusive shock acceleration (DSA) at supernova remnant (SNR) shock fronts is thought to accelerate galactic CRs to energies below the knee, while an extragalactic origin is presumed for CRs with energies beyond the ankle. CRs with energies between 3 × 10 15 and 10 18 eV, which we dub the "shin," have an unknown origin. It has been proposed that DSA at galactic wind termination shocks, rather than at SNR shocks, may accelerate CRs to these energies. This paper uses the galactic wind model of Bustard et al. (2016) to analyze whether galactic wind termination shocks may accelerate CRs to shin energies within a reasonable acceleration time and whether such CRs can subsequently diffuse back to the galaxy. We argue for acceleration times on the order of 100 Myrs rather than a few billion years, as assumed in some previous works, and we discuss prospects for magnetic field amplification at the shock front. Ultimately, we generously assume that the magnetic field is amplified to equipartition. This formalism allows us to obtain analytic formulae, applicable to any wind model, for CR acceleration. Even with generous assumptions, we find that very high wind velocities are required to set up the necessary conditions for acceleration beyond 10 17 eV. We also estimate the luminosities of CRs accelerated by outflow termination shocks, including estimates for the Milky Way wind.
This chapter explores the cross-cultural connections of a community of English and Scottish exiles who fled to the Dutch Republic, c.1575–1688. Among them were Pilgrims and Puritans, preachers-turned-physicians, dozens of dissenting divines, Fifth Monarchists (Dr Edward Richardson), oft-imprisoned Quakers (William Penn), tortured Presbyterians (William Carstares), religious and political exiles (John Locke). They fled to Holland in waves: during the Elizabethan Settlement (late sixteenth century); during the English Civil Wars (1640s); and in the wake of the Restoration Settlement (1660–2). Some sailed back and forth (illegally) during the Anglo-Dutch Wars. Some sided with the Dutch; others played both sides. Joseph Hill was captured on a secret mission back to England in 1666. William Carstares was shipped to Scotland, so he could be tortured. Persecution drove them together.
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