Determination of Mass Limits Around Pulsars at 10 and $90 \mu$ m with ISO

Abstract

We present mid-infrared photometric results obtained with ISOCAM and ISOPHOT on 3millisecond pulsars and 3 ordinary radio pulsars. No detections have beenobtained for the three ms pulsars nor the two more distant radiopulsars. A faint enhancement in the brightness map at 90 microns is seenat about 5 arcsec from the radio position of PSR J0108-1431, thenearest radio pulsar (Tauris et al, 1994), located at 85 pc fromus. We conclude that this 90 micron emission, amounting to about 12mJy, originates either from material orbiting the pulsar or fromcirrus on the line of sight. We deduce the upper limits on mass ofdust orbiting this pulsar and on the mean temperature of grains.