Constraints on the luminosity of the central source in SNR 1987A

We obtained constraints on the luminosity of the central source in SNR 1987 A using XMM-Newton and INTEGRAL data. XMM-Newton yields an upper limit on the SNR luminosity in the 2–10 keV energy band, L_X ? 5 × 10³⁴ erg s^?1. Since the optical depth of the envelope is still large in the XMM-Newton energy band, this constraint carries no useful information about the luminosity of the central source. The optical depth is expected to be small in the hard (20–200 keV) X-ray band of the IBIS telescope aboard the INTEGRAL observatory. We detected no statistically significant emission from SNR 1987 A in the INTEGRAL data and obtained an upper limit of L_X ? 1.1 × 10³⁶ erg s^?1 on the luminosity of the central source in the 20–60 keV band. We also obtained an upper limit on the mass of radioactive ⁴⁴Ti, M(⁴⁴Ti) ? 10^?3M_⊙.