Fast X-Ray Transient EP260321a: Shock Breakout through an Extended Circumstellar Matter
Abstract The Einstein Probe (EP) has discovered a fast X-ray transient, EP260321a, whose optical counterpart was subsequently classified as a broad-lined Type Ic supernova. Its observed rise time of about 690 s is inconsistent with theoretical predictions for shock breakout (SBO) from a Wolf–Rayet star, which is typica...