Search for brightness fluctuations in the zodiacal light at 25 MU M with ISO

Abstract

We mapped at 25 mu m five ~0.5(deg) x0.5(deg) fields at low, intermediate and high ecliptic latitude with the photometer onboard the Infrared Space Observatory. The goal was to search for potential structures in the zodiacal light. No structures were seen in these five sample fields. For an aperture of 3' diameter we find an upper limit for the underlying rms brightness fluctuations of +/-0.2%, which corresponds at high ecliptic latitudes to +/-0.04 MJy/sr or +/-25mJy in the beam. Based on observations with ISO, an ESA project with instruments funded by ESA member states (especially the P/I countries France, Germany, the Netherlands and the United Kingdom) with participation of ISAS and NASA.