Radiation image capturing apparatus and radiation image capturing system

A radiation image capturing apparatus, comprising:

• a plurality of pixels two-dimensionally arranged in an image capturing area and configured to convert incident radiation into electric signals;
• a plurality of driving lines for driving the plurality of pixels;
• and
• a readout circuit configured to read out the electric signals of the plurality of pixels,
• wherein the plurality of pixels includes a plurality of first pixels configured to output the electric signals for acquiring a radiation image and a plurality of second pixels configured to output the electric signals for detecting information about irradiation of the image capturing area with the irradiation,
• wherein the plurality of second pixels is arranged as a line-shaped second pixel group in the image capturing area, and the plurality of driving lines is connected to the line-shaped second pixel group, and
• wherein the readout circuit reads out, at different timings, the electric signals group by group to each of which a different one of the plurality of driving lines is connected in the line-shaped second pixel group.