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Frequency of low-mass exoplanets .. what about the non-detections?. Hugh Jones. SIMON O’TOOLE (AAO/HERTFORDSHIRE), CHRIS TINNEY, JEREMY BAILEY, ROB WITTENMYER (UNSW), PAUL BUTLER (CARNEGIE), BRAD CARTER (SOUTHERN QUEENSLAND). Planet mass function. Jupiter. Earth. Neptune.
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Frequency of low-mass exoplanets .. what about the non-detections? Hugh Jones SIMON O’TOOLE (AAO/HERTFORDSHIRE), CHRIS TINNEY, JEREMY BAILEY, ROB WITTENMYER (UNSW), PAUL BUTLER (CARNEGIE), BRAD CARTER (SOUTHERN QUEENSLAND)
Planet mass function Jupiter Earth Neptune
AAPS (Anglo-Australian Planet Search) Nearly 300 nights over last 10 years on 250, V< 7.7 F, G, K, M IV, V stars selected on CaHK and observed with S/N=200 has yielded more than 30 nearby exoplanets (and 18 spectroscopic binaries) Recent programme of operational upgrades Observing sequencer Automated iodine cell Exposure meter Near future – fibre feed
asteroseismological signal function of L/M Based on Sun, Kjeldsen et al. 2008, Alpha Cen A varies by ~20% plus ~10% over Solar cycle
Development of robust simulation system for AAPS data • Use AAPS time stamps and internal errors • Log10P = 0.3, 0.6, 0.9, 1.2 (or 2 to 20 days) • e = 0.0-0.2 in steps of 0.1 • Mass = 0.02, 0.05, 0.1, 0.2, 0.5 MJ • 7, 200 simulations/dataset • Detectability criteria RMS (sim) < RMS (res) Km > 2 dK + RMS (res) Pm > 2dP Chi2 < 3 works for detections of HD16417 and HD4308
Detectability sensitive to mass function 0.01 -10 MJ lines of increasing thickness
Mass function dN/dM ~M-1(~17% of planets host planets with >3 ME and <16 days)
Conclusions • Simulation system can provide assessment of exoplanetary architectures based on RV data • With multiple telescopes and long campaigns (1m/s precision) can constrain • Saturn mass planets out to 6 AU • Neptune mass planets out to 1 AU • Super-Earths out to 0.3 AU • Earth-mass planets out to 0.1 AU