A SEARCH FOR A PULSAR IN THE REMNANT OF SN 1987A WITH THE HUBBLE SPACE TELESCOPE HIGH SPEED PHOTOMETER

摘要

The High Speed Photometer (HSP) on the Hubble Space Telescope (HST) observed the remnant of SN 1987A on four different epochs between 1992 June 2 and 1993 November 4 in a 1600-7000 A bandpass. Each observation was ～40 minutes in duration and used a 100 μs sampling time. Assuming a spectrum like PSR B0540 -69 with similar reddening, the observed count rates imply a time-averaged magnitude V ≈ 18.2. After correcting to the barycenter of the solar system, no periodic signal was found in any data set using autocorrelation function (ACF) analyses with lags from 200 μs to 10 s and power spectral function (PSF) analyses with a Nyquist frequency corresponding to a period of 200 μs, or in trial pulse profiles obtained by binning the data modulo the frequencies of highest significance in the ACF and PSF analyses. Searches for signals with large values of P also proved negative. We estimate an upper limit of V fainter than ～24 for pulsed radiation from any stellar remnant of SN 1987A.