caa a22 4500 467987513 CHVBK 20180323112536.0 cr unu---uuuuu 170328e19900601xx s 000 0 eng 10.1007/BF00049508 doi (NATIONALLICENCE)springer-10.1007/BF00049508 Dynamical friction on a satellite of a disk galaxy: The circular orbit [Elektronische Daten] [M. Valtonen, L. Valtaoja, B. Sundelius, K. Donner, G. Byrd] In a previous paper, we have studied dynamical friction during a parabolic passage of a companion galaxy past a disk galaxy. This paper continues with the study of satellites in circular orbits around the disk galaxy. Simulations of orbit decay in a self gravitating disk are compared with estimates based on two-body scattering theories; the theories are found to give a satisfactory explanation of the orbital changes. The disk friction is strongly dependent on the sense of rotation of the companion relative to the rotation of the disk galaxy as well as on the amount of mass in a spherical halo. The greatest amount of dynamical friction occurs in direct motion if no spherical halo is present. Then the infall time from the edge of the disk is about one half of the orbital period of the disk edge. A halo twice as massive as the disk increases the infall time four fold. The results of Quinn and Goodman, obtained with a non-self-gravitating method, agree well with our experiments with massive halos (Q 0 ≈ 1.5), but are not usable in a more general case. We give analytic expressions for calculating the disk friction in galaxies of different disk/halo mass ratios. Kluwer Academic Publishers, 1990 Dynamical friction nationallicence satellite galaxy nationallicence disk galaxy nationallicence Valtonen M. Turku University Observatory, Copenhagen, Denmark aut Valtaoja L. Turku University Observatory, Copenhagen, Denmark aut Sundelius B. Department of Astronomy, University of Gothenburg and Chalmers University of Technology, Copenhagen, Denmark aut Donner K. Nordita, Copenhagen, Denmark aut Byrd G. Department of Physics and Astronomy, University of Alabama, Alabama, USA aut Celestial Mechanics and Dynamical Astronomy Kluwer Academic Publishers 48/2(1990-06-01), 95-113 0923-2958 48:2<95 1990 48 10569 https://doi.org/10.1007/BF00049508 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00049508 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Valtonen M. Turku University Observatory, Copenhagen, Denmark aut NATIONALLICENCE 700 1- Valtaoja L. Turku University Observatory, Copenhagen, Denmark aut NATIONALLICENCE 700 1- Sundelius B. Department of Astronomy, University of Gothenburg and Chalmers University of Technology, Copenhagen, Denmark aut NATIONALLICENCE 700 1- Donner K. Nordita, Copenhagen, Denmark aut NATIONALLICENCE 700 1- Byrd G. Department of Physics and Astronomy, University of Alabama, Alabama, USA aut NATIONALLICENCE 773 0- Celestial Mechanics and Dynamical Astronomy Kluwer Academic Publishers 48/2(1990-06-01), 95-113 0923-2958 48:2<95 1990 48 10569 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer