2006/05/31 by K. Spekkens, Kristine Spekkens, R. Giovanelli +1
Physics and Astronomy · #Amplitude #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Galaxy rotation curve #Geometry #Optics #Photometry (optics) #Physics #Population #Rotation (mathematics) #Spiral galaxy #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/506177
published as Astron.J.132:1426-1444,2006 · v2: minor changes to match proofs. 23 pages, 15 figures, AJ in press. For version with high resolution figures, see http://www.physics.rutgers.edu/~spekkens/papers/fast1.pdf
arxiv created 2006/07/25 · openalex publication_date 2006/08/15 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present I -band photometry, long-slit optical spectroscopy, and new aperture synthesis H I observations for eight late-type spiral galaxies with rotation velocities in the range 243 km s -1 ≲ V rot ≲ 308 km s -1 . The sample will be used to study the structure and angular momentum of disks at the high-mass end of the spiral galaxy population; here we discuss the basic properties of these "fast rotators" and derive hybrid optical/H I rotation curves for each. Despite the presence of H I warps and low-mass companions in many systems, their kinematics are regular and there is excellent agreement between optical and H I tracers near the optical radius r opt . At high inclinations at which projection effects are negligible, the sample galaxies exhibit flat, featureless rotation curves out to their last measured points at 1.7 r opt -3.5 r opt . The intermediate-inclination systems are also consistent with a constant rotation amplitude for r ≳ 0.5 r opt . We therefore find no evidence for declining rotation curves at the high-mass end of the late-type spiral galaxy population. Combining our data with the compilation of spiral galaxies with reliable outer H I kinematics from the work of Casertano and van Gorkom, we find no convincing trends between logarithmic outer rotation curve slopes and rotation amplitudes or surface brightnesses for galaxies with V rot ≳ 220 km s -1 . Correlations between these slopes and morphological types or disk scale lengths are also marginal in this regime.