Impact Of MMR Architecture On The Stability And Detection Of Planetary Systems

The architecture of the planets in the solar system has long been the only target for planetary science research.Since the discovery of the first planet in 1988,nearly 4000 extrasolar planets have been detected and confirmed.They provide us a diverse and different world full of planets.For instance,hot Jupiters with orbital periods as short as several days,warm Jupiters with companions,super-Earth with masses as large as tens of the Earth mass and compact multi-planet systems which contain planet pairs in mean motion resonances(MMRs),indicating quite different formation histories among these different population.There are two mechanisms proposed to explain the origins of the planets with short orbital periods,migration and in-situ formation.Generally,MMR architectures are considered to be the product of disk migration.This paper focused on the MMR architecture and its impact on characterization,stability and detection of extrasolar planets.In the first chapter,we briefly introduced the history of both solar planets and extra-solar planets detection.We compared the similarities and differences of their architec-ture and stability.For extrasolar planets,we concentrated on three kinds of populations-hot Jupiters,warm Jupiters,super-Earth and Neptune like planets.We analyzed their formation mechanisms and characteristics.Also,we discussed the MMR architecture and the occurrence rate of extrasolar planets.In the second chapter,we discussed the possibility and advantage of character-izing architectures and constraining parameters for planet pairs near MMRs using the transit time variation data.We fitted the transit time variations for several warm Jupiter systems with the Markov Chain Monte Carlo method.Based on the fitted planetary mass,we confirmed that three warm Jupiter candidates are real Jupiters.We also com-pared the relationship between planetary radius and effective temperature for warm Jupiters and hot Jupiters and found that the two kinds of Jupiters can be separated by Teff,c = 1123.7± 3.3 K.Moreover,we predicted the transit time of Kepler-9 b based on the parameters obtained from the transit time fitting results and we successfully cap-tured the transit signal.In the third chapter,we examined the effects that dynamical instability has on shaping the orbital period ratio distribution.We conducted numerical N-body simula-tions on non-EMS(Equal mutual Separation)multi-planet systems.Simulation results show that the lower limit of the instability time-scale is determined by the minimal mu-tual separation.Planetary systems that show instabilities generally contain planet pairs with period ratios<1.33.The final period ratio distributions shows dip-peak structure near the MMRs,consistent with the observation.By comparing the simulation results and the observation,we found that there is a lack of planet pairs with period ratio>2.1,possibly caused by planetary migration or planet pairs just tend to form with smaller period ratios.At the same time,we obtained the upper limit of eccentricity for planets.Finally,were-defined "compact" based on our simulation results.In the fourth chapter,we discussed the possibility of detecting single-planet sys-tems and planetary systems with planet pairs in MMRs via the astrometry method with a precision of ?as.We simulated the detecting process,injected different observational errors and generated observational data.Then we analyzed the simulated data to see if we can extract planetary signal from these data.For single-planet systems and plane-tary systems with planet pairs in MMRs,the single-detection signal-noise-ratio(S/N)should be larger than 3 to ensure the detection of planets.To reproduce the MMR ar-chitecture,S/N should be even larger.Three kinds of MMRs,2:1,3:2 and 4:3 were considered.And it turned out that the probability of reconstructing the MMR architec-ture for 2:1 MMR is the most difficult because of influence of harmonics.We found that the MMR reconstruction probability is related with the planetary eccentricity and resonance intensity.Finally,we predicted the number of planet pairs in MMRs that can be detected and discussed the influence of sampling method on planet detection.Our conclusions and prospects for extrasolar planets in the future are outlined in the final chapter.Based on the current observational techniques and samples,many discussions on extrasolar planetary properties are from statistics.The detailed char-acterization for single planetary system would be one of the emphases for research in future with the launch of JWST and WFIRST.