  Solar X-ray jets are evidently made by a burst of reconnection of closed
magnetic field in a jet's base with ambient "open" field (1,2). In the
widely-accepted version of the "emerging-flux" model, that reconnection occurs
at a current sheet between the open field and emerging closed field and also
makes a compact hot brightening that is usually observed at the edge of the
jet's base (1,3). Here we report on high-resolution X-ray and EUV observations
of 20 randomly-selected X-ray jets in polar coronal holes. In each jet,
contrary to the emerging-flux model, a miniature version of the filament
eruptions that initiate coronal mass ejections (CMEs) (4-7) drives the
jet-producing reconnection, and the compact hot brightening is made by internal
reconnection of the legs of the minifilament-carrying erupting closed field,
analogous to solar flares of larger-scale eruptions. Previous observations have
found that some jets are driven by base-field eruptions (8-10,12), but only one
such study, of only one jet, provisionally questioned the emerging-flux model
(13). Our observations support the view that solar filament eruptions are made
by a fundamental explosive magnetic process that occurs on a vast range of
scales, from the biggest CME/flare eruptions down to X-ray jets, and perhaps
down to even smaller jets that are candidates for powering coronal heating
(10,14,15). A picture similar to that suggested by our observations was drawn
before, inferred from different observations and based on a different origin of
the erupting minifilament flux rope (11) (see Methods).
