Rotation Curves Of Spiral Galaxies Research Articles

Extended rotation curves of high-luminosity spiral galaxies. III - The spiral galaxy NGC 7217

view Abstract Citations (27) References (27) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Extended rotation curves of high-luminosity spiral galaxies. III. The spiral galaxy NGC 7217. Peterson, C. J. ; Rubin, V. C. ; Ford, W. K., Jr. ; Roberts, M. S. Abstract NOC 7217 is an isolated Sab galaxy with a relatively fiat rotation curve, predominantly circular motions, and high maximum rotational velocity, Vmax = 290 km 1 The total mass out to the final measured velocity is = 1.2 + 0.1 x 1011 (R = 10.5 kpc); we estimate < 3 x 10" if the rotation curve remains flat to the Holmberg radius, R = 26.6 kpc. The ratio of mass to blue luminosity increases from unity at R = 1 kpc to no more than 6 at R = 26.6 kpc. The hydrogen mass, Hi = 1.7 x 10 , is low with respect to both the blue luminosity and the total mass, making the hydrogen properties of NOC 7217 much like those of an SO or Sa galaxy. Broad nuclear emission lines ( 700 km S-' total width for [N ii] A6583) imply a nuclear mass = 10 within R = 100 pc. Subject headings: galaxies: individual - galaxies: internal motions Publication: The Astrophysical Journal Pub Date: December 1978 DOI: 10.1086/156658 Bibcode: 1978ApJ...226..770P Keywords: Galactic Rotation; Luminosity; Spiral Galaxies; Galactic Evolution; Galactic Radiation; Radial Velocity; Astronomy; Luminosities:Spiral Galaxies; Masses:Spiral Galaxies; Rotation:Spiral Galaxies full text sources ADS | data products NED (1) Related Materials (4) Part 1: 1977ApJ...217L...1R Part 2: 1978ApJ...224..782R Part 4: 1978ApJ...225L.107R Part 5: 1979ApJ...230...35R

Extended rotation curves of high-luminosity spiral galaxies. IV - Systematic dynamical properties, SA through SC

For a sample of 10 high-luminosity spiral galaxies, Sa through Sc, we have obtained accurate rotation curves which extend to about 80% of the de Vaucouleurs radii.

Extended rotation curves of high-luminosity spiral galaxies. II - The anemic SA galaxy NGC 4378

view Abstract Citations (34) References (34) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Extended rotation curves of high-luminosity spiral galaxies. II. The anemic Sa galaxy NGC 4378. Rubin, V. C. ; Ford, W. K., Jr. ; Strom, K. M. ; Strom, S. E. ; Romanishin, W. Abstract Spectroscopic and photometric observations are reported for the Sa galaxy NGC 4378. Our data suggest that this galaxy is located at a distance of 50 Mpc; if so, its absolute blue luminosity MB = -21.1. From an analysis of its rotation curve, a total mass, = 3.6 + 0.5 x 10" , is derived. The mass to blue-luminosity ratio increases from /LB = 4.0 for regions within 2 kpc of the nucleus to /LB 10 in the outer regions of the galaxy. The hydrogen-mass to blue- luminosity ratio, HI/LB 0.1, is quite typical of early-type galaxies. Star formation in NGC 4378 follows a pattern qualitatively similar to that in our own Galaxy. Newly formed stars are virtually absent in the nuclear bulge region but increase in relative number out to a radius of 18 kpc, beyond which the star-formation rate drops. Ionized hydrogen regions in NGC 4378 show a ratio [N ii]/Ha which drops below unity only beyond 10 kpc. This result suggests that metal enrichment in the disk of this galaxy may have proceeded to a greater degree and over a larger fraction of the disk than is typical of other early-type galaxies. NGC 4378 has been called an "anemic" spiral by van den Bergh. This classification appears to result from the combined influences of a somewhat fainter than normal disk surface brightness and a lower star-forming efficiency in its arms. Subject headings: galaxies: individual - galaxies: internal motions - galaxies: photometry - galaxies: stellar content - galaxies: structure Publication: The Astrophysical Journal Pub Date: September 1978 DOI: 10.1086/156426 Bibcode: 1978ApJ...224..782R Keywords: Astronomical Photometry; Astronomical Spectroscopy; Galactic Rotation; Galactic Structure; Spiral Galaxies; Astrometry; Brightness; Emission Spectra; Galactic Evolution; Hydrogen; Mass Distribution; Mass Ratios; Stellar Evolution; Ubv Spectra; Astronomy; Photometry:Spiral Galaxies; Spiral Galaxies:Internal Motions; Spiral Galaxies: Structure full text sources ADS | data products NED (2) Related Materials (4) Part 1: 1977ApJ...217L...1R Part 3: 1978ApJ...226..770P Part 4: 1978ApJ...225L.107R Part 5: 1979ApJ...230...35R

Extended rotation curves of high-luminosity spiral galaxies. I - The angle between the rotation axis of the nucleus and the outer disk of NGC 3672

A large velocity gradient is observed in the excited nuclear gas of NGC 3672 when the slit is aligned along the minor axis, and a nuclear velocity gradient smaller than that implied by the rotation curve of the outer disk is observed with the slit along the major axis. The most direct interpretation of this obsevation is that the rotation axis of the nuclear gas disk makes a large angle with the rotation axis of the outer galaxy as a whole. An alternative explanation is that the nuclear gas is not rotating, but contracting (at about 50 km/s) in the plane of the outer disk. Both models imply that a transient phenomenon is being observed. The nucleus is small, less than 350 pc, and of low mass about 200 million solar masses, compared with a galaxy mass of approximately 140 billion solar masses.