Constraints on Extrasolar Planet Populations from VLT NACO/SDI and MMT SDI and Direct Adaptive Optics Imaging Surveys: Giant Planets are Rare at Large Separations

摘要: We examine the implications for distribution of extrasolar planets based on null results from two largest direct imaging surveys published to date. Combining measured contrast curves 22 stars observed with VLT NACO adaptive optics system by Masciadri and coworkers 48 SDI MMT devices Biller (for a total 60 unique stars), we consider what distributions planet masses semimajor axes can be ruled out these data, Monte Carlo simulations populations. set following upper limit 95% confidence: fraction axis between 20 100 AU, mass above 4 MJup, is 20% or less. Also, -->dN/dM M?1.16 in range 0.5-13 rule power-law ( -->dN/da a?) index 0 cutoff 18 -0.5 an AU. For suggested Cumming et al., ?0.61, place 75 AU distribution. In general, find that even are very powerful constraining giant (0.5-13 MJup) at large separations, but more work needs done close gap detected imaging, those which radial velocity method sensitive.