Search for protoplanetary and debris disks around millisecond pulsars

The identification of planetary companions around the nearby millisecond radio pulsar PSR B1257 + 12 implies that planetary formation has occurred in the past evolutionary history of this system. If planetary formation is common around millisecond pulsars and if it occurs by coalescence of small dust particles within a protoplanetary disk, as is thought to have occurred during the formation of the solar system, then it may be possible to detect the presence of protoplanetary dust or a remnant debris disk via thermal infrared emission. We summarize an attempt to detect this emission via a series of 10 mu m observations made toward PSR B1257 + 12 and four other nearby millisecond pulsars using the National Aeronautics and Space Administration (NASA) Infrared Telescope Facility (IRTF) 3 m telescope and the facility bolometer. We also present a simple model for thermal emission from a protoplanetary disk containing grains heated from the pulsar spin-down luminosity. Further, we describe upcoming space-based far-infrared observations that can substantially improve observational limits from the emission of dust that may radiate in the two order of magnitude gap between ground-based accessible mid-infrared and millimeter spectral regions.