The float zone (high-resistance) silicon irradiated with swift heavy ions was studied by photoluminescence (PL) spectroscopy method. In addition to well-known X, W, W’, R and C lines, a broad peak (1.3 – 1.5 μm) appears in PL spectra at low-temperatures. As the irradiation dose increases from 3•10_11 to 10_13 cm-2, the PL intensity decreases by about an order of magnitude, also a narrowing of the peak with red-shift is observed.