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) ≲ 10-3 M ⊙.