Publication Abstracts
Contopoulos and Strömgren 1965
Contopoulos, G., and B. Strömgren, 1965: Tables of Plane Galactic Orbits. NASA Goddard Institute for Space Studies.
For the purpose of calculation of tables of plane galactic orbits the force function F(R) was derived from the rotational-velocity function Θ(R) as determined from 21cm observations for R between 3.5 and 10 kpc and from optical observations between 10 kpc and 13 kpc. The values of the Oort constants A nd B were taken to be +15 km/sec/kpc and -10 km/sec/kpc respectively, while the distance Ro of the sun from the galactic center and the rotational velocity of Ro were assumed to be 10 kpc and 250 km/sec. The force function
F = 73340/R2 - 1581.8 + 3443.03R - 402.621R2 + 12.9402R3
was found to reproduce the observed Θ(R) curve within 1 km/sec. This force function is not valid for R > 14 kpc.
With the expression for F(R) given above a number of plane galactic orbits were calculated by numerical integration using an IBM 7094 computer at the NASA Institute for Space Studies in New York. The initial position for time T=0 was taken to be that of the sun. The tabulated orbits cover a range of initial velocities in the direction of galactic rotation from 190 km/sec to 270 km/sec with st4eps of 10 km/sec and a range of radial velocities from -100 km/sec to +100 km/sec (-80 km/sec to +80 km/ssec for values of the velocity in the direction of galactic rotation ≥ 260 km/sec, steps of 10 km/sec). The orbits were calculated backwards in time, and the coordinates and velocity data are tabulated with a time interval of 1×107 years up to T = -60×107 years.
The tables are useful in studies of the connection between present locations and space velocities of stars and their places and velocities at formation, particularly in the case that individual stellar ages of adequate accuracy are available.
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BibTeX Citation
@book{co07300k,
author={Contopoulos, G. and Strömgren, B.},
title={Tables of Plane Galactic Orbits},
year={1965},
publisher={NASA Goddard Institute for Space Studies},
address={New York, N.Y.},
}
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RIS Citation
TY - BOOK ID - co07300k AU - Contopoulos, G. AU - Strömgren, B. PY - 1965 BT - Tables of Plane Galactic Orbits PB - NASA Goddard Institute for Space Studies CY - New York, N.Y. ER -
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