On the Rotation of the Inner Parts of the Galactic System.

Abstract

view Abstract Citations (18) References (13) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the Rotation of the Inner Parts of the Galactic System. Münch, Guido ; Münch, Luis Abstract Results of radial-velocity measurements for 18 distant OB stars in galactic longitudes between 345 and 35 are presented. On the basis of published spectroscopic distance moduli, the results have been interpreted in terms of rotational velocities around the galactic center and compared with those of the interstellar neutral hydrogen. The stellar motions seem to suggest for the rotational velocity of the galactic system, at a distance of 6 kpc from the center, a value 10 km/sec higher than that indicated by the 21-cm line. At a distance of 4 kpc from the center, the stellar motions provide rotational velocities around 25 km/sec lower than the 21-cm line profiles do. This discrepancy is shown to be unlikely to arise from systematic errors in the spectroscopic distance moduli or in the radial velocities. The motion of the stars considered indicates a value for Oort's constant A somewhat larger than the classical value A = 20 km/sec. The BO.S Ia star HD 173438 has been found to be a single-line spectroscopic binary with a 250- day period, a semiamplitude of 50 km/sec, and an eccentricity of 0.54. Publication: The Astrophysical Journal Pub Date: March 1960 DOI: 10.1086/146830 Bibcode: 1960ApJ...131..253M full text sources ADS | data products SIMBAD (18)