This is a repository for posterior samples of the 55 Cancri planetary system. Methodological and science details can be found here.
The two files listed above represent a different observational model. Case 1 assumes uncorrelated radial velocity observations. Case 2 assumes back-to-back radial velocity observations (< 10 minutes apart) are perfectly correlated. If you must choose only one of the two, we recommend using Case 2.
Each line represents a draw from a Markov chain Monte Carlo. Each line contains 68 values. They read as follows.
MCMC information:
Column 1: Markov chain generation Column 2: Markov chain index Column 3: Chi squared with jitter penalty term
Orbital Parameter information. Each planet has 9 parameters:
Columns 4, 13, 22, 31, 40: Orbital period in [days] for planets "e", "b", "c", "f", and "d" respectively. Columns 5, 14, 23, 32, 41: RV half amplitude in [m/s] for planets "e", "b", "c", "f", and "d" respectively. Columns 6, 15, 24, 33, 42: mass in [solar masses] for planets "e", "b", "c", "f", and "d" respectively. Columns 7, 16, 25, 34, 43: semi-major axis in [AU] for planets "e", "b", "c", "f", and "d" respectively. Columns 8, 17, 26, 35, 44: eccentricity for planets "e", "b", "c", "f", and "d" respectively. Columns 9, 18, 27, 36, 45: inclination in [degrees] for planets "e", "b", "c", "f", and "d" respectively. Columns 10, 19, 28, 37, 46: argument of pericenter in [degrees] for planets "e", "b", "c", "f", and "d" respectively. Columns 11, 20, 29, 38, 47: longitude of ascending node in [degrees] for planets "e", "b", "c", "f", and "d" respectively. Columns 12, 21, 30, 39, 48: mean anomaly at the epoch of the first Lick observation in [degrees] for planets "e", "b", "c", "f", and "d" respectively.
Instrumental parameter information:
Columns 49, 50, 51, 52, 53: Lick observatory RV offsets Columns 54, 55: Keck HIRES RV offsets Column 56: HET RV offset Column 57: HJST RV offset Columns 58, 59, 60: Lick observatory jitters Column 61: Keck jitter Column 62: HET jitter Column 63: HJST jitter
Supplementary information:
Column 64: Chi squared without jitter Column 65: Run length (number of subsequent states in the Markov chain without an Metropolis-Hastings acceptance) Column 66: Chi squared with jitter (no penalty term) Column 67: Stellar radius in [AU] Column 68: Stellar mass in [solar masses]
Please cite Nelson et al. (2014) if you use these posterior samples in your research.
The BibTeX entry for the paper is:
@ARTICLE{2014MNRAS.441..442N, author = {{Nelson}, B.~E. and {Ford}, E.~B. and {Wright}, J.~T. and {Fischer}, D.~A. and {von Braun}, K. and {Howard}, A.~W. and {Payne}, M.~J. and {Dindar}, S. }, title = "{The 55 Cancri planetary system: fully self-consistent N-body constraints and a dynamical analysis}", journal = {\mnras}, archivePrefix = "arXiv", eprint = {1402.6343}, primaryClass = "astro-ph.EP", keywords = {methods: statistical, techniques: radial velocities, planets and satellites: dynamical evolution and stability}, year = 2014, month = jun, volume = 441, pages = {442-451}, doi = {10.1093/mnras/stu450}, adsurl = {http://adsabs.harvard.edu/abs/2014MNRAS.441..442N}, adsnote = {Provided by the SAO/NASA Astrophysics Data System} }