The assumption of pole isotropy entails a "Maxwellian" distribution of the angular velocity of asteroids. Nevertheless, it is becoming more and more apparent that the isotropy assumption may not hold, while, on the other hand, the observed spin distribution cannot be always represented by a single maxwellian. It is interesting to check whether these difficulties may be related. On the basis of the existing data on poles, we plot possible multivariate distributions statistically consistent with the data, looking for the resulting non-maxwellian spin distributions. It comes out that the distributions fitting the pole data exhibit only a slight excess at large ω values. More severe anisotropies (which one might find to affect particular samples, such as dynamical families, and so on) give spectacular deviations. The extension of the observational efforts to assign asteroid poles is required.
Pole anisotropy and spin statistics
LA SPINA, ALESSANDRA;PAOLICCHI, PAOLO;
2002-01-01
Abstract
The assumption of pole isotropy entails a "Maxwellian" distribution of the angular velocity of asteroids. Nevertheless, it is becoming more and more apparent that the isotropy assumption may not hold, while, on the other hand, the observed spin distribution cannot be always represented by a single maxwellian. It is interesting to check whether these difficulties may be related. On the basis of the existing data on poles, we plot possible multivariate distributions statistically consistent with the data, looking for the resulting non-maxwellian spin distributions. It comes out that the distributions fitting the pole data exhibit only a slight excess at large ω values. More severe anisotropies (which one might find to affect particular samples, such as dynamical families, and so on) give spectacular deviations. The extension of the observational efforts to assign asteroid poles is required.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
