| Description |
We plan to use the unique photometric capabilities provided by Herschel to perform a deep and systematic survey for faint, cold debris disks. We propose a sensitivity-limited Herschel Key Programme that aims at finding and characterizing faint exo-solar analogues to the Edgeworth-Kuiper Belt in a statistical sample of 283 nearby main-sequence stars. Our sample is volume-limited (distances < 25 pc) and covers a decade in stellar mass from 0.2 to 2 solar masses (M- to A-type stars). This will provide an unprecedented lower limit to the fractional abundance of planetesimal systems, and act as a proxy to assess the presence of giant planets resembling the roles played by Neptune and Jupiter in the solarsystem. We will perform PACS and SPIRE photometric observations covering the wavelengthrange from 70 to 500 micron. PACS observations at 100 micron have been designed to detect the stellar photospheres down to the confusion noise with a signal to noise ratio at least 5. Observations in the other Herschel bands will allow usto characterize, model, and constrain the disks. As a result, it will be possible for us to reach fractional luminosities L(dust)/L(star) a few times 10^(-7), close to the EKB level in our solar system.The extensive and unique data set will allow us to address some fundamental questions related to exo-EKBs:- Dependence of planetesimal formation on stellar mass.- Collisional and dynamical evolution.- Correlation with planets.- Dust properties and size distribution.Herschel is the first and the only facility for the foreseeable future which is providing the observational capability required to successfully addressing thescientific case we are proposing. The outcome of this project has high science legacy and outreach values that will impact on studies related to planet formation and planetary systems. |
