WIYN Integral-Field Kinematics of Disk Galaxies

We have completed a new fiber array, SparsePak, optimized for low-surface-brightness studies of extended sources on the WIYN telescope. We are now using this array as a measuring engine of velocity and velocity-dispersion fields of stars and ionized gas in disk galaxies from high to low surface-brightness. Here we present commissioning data on the velocity ellipsoids, surface densities and mass-to-light ratios in two blue, high surface-brightness, yet small disks. If our preliminary results survive further observation and more sophisticated analysis, then NGC 3949 has sigma_z/sigma_R >> 1, implying strong vertical heating, while NGC 3982's disk is substantially sub-maximal. These galaxies are strikingly unlike the Milky Way, and yet would be seen more easily at high redshift.Comment: to appear in Disk Galaxies: Kinematics, Dynamics and Perturbations, eds. E. Athanassoula and A. Bosma, ASP Conference Series; 4 pages with 4 embedded figure

The Symmetry, Color and Morphology of Galaxies in the Hubble Deep Field

We present a new method of utilizing the color and asymmetry values for galaxies in the Hubble Deep Field to determine both their morphological features and physical parameters. By using a color-asymmetry diagram, we show that various types of star-forming galaxies (e.g. irregular versus interacting, peculiar galaxies) can be distinguished in local samples. We apply the same methods to the F814W images of the Hubble Deep Field, and show preliminary results indicating that galaxy mergers and interactions are the dominate process responsible for creating asymmetries in the HDF galaxies.Comment: 5 Pages with 1 figure; To appear in "After the Dark Ages: When Galaxies were Young", proceedings of the 9th annual October Astrophysics Conference, ed. S. Holt and E. Smit

The Intrinsic Ellipticity of Spiral Disks

We have measured the distribution of intrinsic ellipticities for a sample of 28 relatively face-on spiral disks. We combine H-alpha velocity fields and R and I-band images to determine differences between kinematic and photometric inclination and position angles, from which we estimate intrinsic ellipticities of galaxy disks. Our findings suggest disks have a log-normal distribution of ellipticities (mean epsilon =0.06) and span a range from epsilon= 0 (circular) to epsilon=0.2. We are also able to construct a tight Tully-Fisher relation for our face-on sample. We use this to assess the contribution of disk ellipticity on the observed Tully-Fisher scatter.Comment: 4 pages, 2 figures, to appear in "Disks of Galaxies: Kinematics, Dynamics and Perturbations" (ASP Conference Series), eds E.Athanassoula and A. Bosm