标题： 修改后的动力学预测与暗弱矮星系中HI运动学的观测结果一致，这与Lo Sargent和Young的结论相反 显示英文标题

标题： Modified-dynamics predictions agree with ovservations of the HI kinematics in faint dwarf galaxies contrary to the conclusions of Lo Sargent and Young

摘要： 洛、萨金特和杨（1993）最近得出结论，一些矮星系的质量，根据观测速度弥散由修改动力学（MOND）推导出的质量，系统地比观测质量小一个数量级或更多。我们在这里表明，洛等人使用的MOND质量估计器比正确的表达式小约二十倍。我们推导出正确的质量估计器，作为三维均方根速度Vs和任意自引力系统总质量M之间的精确类似维里定理的关系，该系统由轻质组分组成，并且处于MOND的非常低加速度区域。其形式为M=(9/4)Vs^2/G a0。（对于非静止系统，Vs还涉及时间的平均。）我们进一步将此关系推广到组分质量与整个系统质量相比不很小时的情况。我们讨论了M-V关系的各种应用。使用正确的估计器，MOND的预测大致与总观测质量（观测气体质量加上对应于约一个太阳单位M/L的恒星质量）一致。 显示英文摘要

摘要： Lo, Sargent, and Young (1993) have recently concluded that the masses of some dwarf galaxies, as deduced by the modified dynamics (MOND) from the observed velocity dispersions, are systematically smaller than the observed masses, by a factor of ten or more. We show here that the MOND mass estimator used by Lo et al. is smaller than the proper expression, by a factor of about twenty. We derive the proper mass estimator as an exact virial-like relation between the 3-D rms velocity, Vs, and the total mass, M, of an arbitrary, self-gravitating system, made of light constituents, that is everywhere in the very-low-acceleration regime of MOND. This reads M=(9/4)Vs^2/G a0. (For a system that is not stationary, Vs involves also an average over time.) We further generalize this relation to cases with constituent masses that are not small compared with that of the whole system. We discuss various applications of the M-V relation. With the correct estimator the predictions of MOND are, by and large, in good agreement with the total observed masses (the observed gas mass plus a stellar mass corresponding to an M/L of order one solar unit).