Science Capabilities of the TPF Interferometer: the First Iteration

摘要

Over the last year, a set of well defined science requirements has been established for the Terrestrial Planet Finder (TPF) mission. They consist of top level specifications, such as the number and charateristics of stars to be observed, the planetary sizes and orbital phase spaces to be searched for, the desired completeness of the search, etc. For each of the concurrent observing techniques considered - thermal infrared nulling interferometry and optical coronagraphy-, dedicated spectroscopy requirements have also been formulated. On the interferometry side, the most promising design studied so far consists of a free flyer assembly of four 4 m class telescopes. It basically allows to thoroughly search for planets in the habitable zone of ～ 160 nearby main sequence F,G and K dwarfs in 1 year of continuous integration (～ 2 years of operation). Over 1.5 year of subsequent observation, this design would also enable low resolution (20) spectroscopic characterization of up to 10 exo-planetary atmospheres in the [6.5 - 17] micron range, assuming 260 K exo-planets with Earth albedo, and at least half the Earth area are present around the target stars. With only minor additions to the nulling design, and taking advantage of a spatial resolution 10 to 50 times higher than JWST, the free flyer design would also provide fantastic contributions in the fields of comparative planetology, the study of very young stellar objects and high-z galaxies.