Selection Effect in Semimajor Axes of Orbits of Extrasolar Planets
Tóm tắt
We present a detailed analysis of the distribution of semimajor axes of orbits of extrasolar planets detected by the method of radial velocity measurements. The relation obtained enables one to calculate the probability of the discovery of a planet at a distance r from a star, knowing the masses of the star and the planet and the threshold radial velocity. The selection effect is manifested in the transformation of the distribution functions. A relation is found between the true and observable distributions of the quantity r. The “domain of detectability” of extrasolar planets is examined under various assumptions about the form of the distribution functions. The available statistical data on observable extrasolar systems are shown to be inadequate to draw detailed conclusions about their structure. Although substantial differences are found between the structures of all detected planetary systems and that of the Solar System, it would be premature to assert the uniqueness of the latter.
Tài liệu tham khảo
Agekian, T.A., Teoriya veroyatnostei dlya astronomov i fizikov (Probability Theory for Astronomers and Physicists), Moscow: Nauka, 1974.
Cumming, A., Marcy, G.W., and Butler, R.P., The Lick Planet Search: Detectability and Mass Thresholds, Astrophys. J., 1999, vol. 526, pp. 890-915.
Ksanfomality, L.V., The Search for Extrasolar Planets by Means of Radial-Velocity Spectral Method and Astrometry, Astron. Vestn., 1999, vol. 33, no. 6, pp. 547-552 [Sol. Syst. Res. (Engl. transl.), 1999, vol. 33, no. 6, pp. 482-486].
Ksanfomality, L.V., Extrasolar Planetary Systems, Astron. Vestn., 2000, vol. 34, no. 6, pp. 529-544 [Sol. Syst. Res. (Engl. transl.), 2000, vol. 34, no. 6, pp. 481-495].
Ksanfomality, L.V., Planetary Systems of Other Stars, Vserossiiskaya astronomicheskaya konferentsiya (All-Russia Astronomical Conference, Abstracts), St. Petersburg: NIICh SPSU, 2001, p. 103.
Marcy, G.W., Butler, R.P., Fisher, D., et al., Masses and Orbital Characteristics of Extrasolar Planets Using Stel-lar Masses Derived from Hipparcos, Metallicity, and Stellar Evolution. http://exoplanets.org., 2002.
Perryman, M.A.C., Extra-Solar Planets, Rep. Prog. Phys., 2000, vol. 63, pp. 1209-1272.
Schneider, J., The Study of Extrasolar Planets: Method of Detection, First Discovery and Future Perspectives, C. R., Acad. Sci. Paris, 1999, vol. 327, Série IIb, no. 6, pp. 621-637.
Schneider, J., The Extrasolar Planets Encyclopaedia. http://www.obspm.fr/encycl/catalog.html, 2002.
Udry, S. and Mayor, M., The Diversity of Extra-Solar Planets around Solar-Type Stars, in Lecture Notes in Physics: Astrobiology, Springer, 2002 (in press).