Forward<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="italic">K</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>Production in Subthreshold<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">pA</mml:mi></mml:math>Collisions at 1.0 GeV

${K}^{+}$-meson production in $\mathrm{pA}$ ( $A\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\mathrm{C},\mathrm{Cu},\mathrm{Au}$) collisions has been studied using the ANKE spectrometer at an internal target position of the COSY-J\"ulich accelerator. The complete momentum spectrum of kaons emitted at forward angles, $\ensuremath{\vartheta}\ensuremath{\le}12\ifmmode^\circ\else\textdegree\fi{}$, has been measured for a beam energy of ${T}_{p}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.0\mathrm{GeV}$, far below the free $\mathrm{NN}$ threshold of 1.58 GeV. The spectrum does not follow a thermal distribution at low kaon momenta and the larger momenta reflect a high degree of collectivity in the target nucleus.