A Simple Depth-of-Search Metric for Exoplanet Imaging Surveys

摘要

We present a procedure for calculating expected exoplanet imaging yields?that?explicitly separates the effects of instrument performance from assumptions of planet distributions. This "depth-of-search" approach allows for fast recalculation of yield values for variations in instrument parameters. We also describe a new target star selection metric with no dependence on an assumed planet population that can be used as a proxy for single-visit completeness. This approach allows for the recovery of the total mission completeness via convolution of the depth-of-search grid with an equivalent grid of assumed occurrence rates and summation over the part of the grid representing the population of interest (e.g., Earth-like planets on habitable zone orbits, etc.). In this work, we discuss the practical details of calculating the depth-of-search and present results of such calculations for one design iteration of the WFIRST coronagraphs.