view Abstract Citations (52) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Velocity dispersions in galaxies. III. The nucleus of M31. Morton, D. C. ; Thuan, T. X. Abstract A stigmatic spectrum covering 116" through the pointlike nucleus of M31 was obtained with the Princeton integrating television system at the coude' spectrograph of the Hale telescope. The spectrum covered the range 4918 to 5302 A at a resolution of 0.66 A or 39 km s ' with the slit in the E-W direction about 38 from the major axis of the nucleus. The seeing disk had a diameter of about 4" at half the peak light. Comparison of our spectrum with standard G8 III, K0 III, and K3 III stars broadened for various velocity dispersions gives a line-of-sight dispersion at the center of M31 of a = 120 I 30 km s-' with no detectable change out to 113". The spectral lines appear to have a rotational tilt of 20 km s ' (arc sec) -1 out to 13" where the velocities reach +62 and -44 km s-' and then return close to zero. If the nucleus of M3 1 can be considered a dynamical entity, application of the virial theorem, including the effect of rotation, gives a mass of (1.8 1 0.8) x 108 M0 and a ratio of mass to visual light of 13 M0/Ly0. Subject headings: galactic nuclei - galaxies, motions in Publication: The Astrophysical Journal Pub Date: March 1973 DOI: 10.1086/152000 Bibcode: 1973ApJ...180..705M full text sources ADS | data products SIMBAD (4) NED (1) Related Materials (4) Part 1: 1972ApJ...174..489M Part 2: 1973ApJ...179...55M Part 4: 1977ApJ...212...13M Part 5: 1976ApJ...205...63M
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