2D kinematics of the edge-on spiral galaxy ESO 379-006 (original) (raw)

TWO-DIMENSIONAL KINEMATICS OF THE EDGE-ON SPIRAL GALAXY ESO 379-006

The Astronomical Journal, 2013

ABSTRACT We present a kinematical study of the nearly edge-on galaxy ESO 379-006 that shows the existence of extraplanar ionized gas. With Fabry-Perot spectroscopy at Hα, we study the kinematics of ESO 379-006 using velocity maps and position-velocity diagrams parallel to the major and to the minor axis of the galaxy. We build the rotation curve of the disk and discuss the role of projection effects due to the fact of viewing this galaxy nearly edge-on. The twisting of the isovelocities in the radial velocity field of the disk of ESO 379-006 as well as the kinematical asymmetries found in some position-velocity diagrams parallel to the minor axis of the galaxy suggest the existence of deviations to circular motions in the disk that can be modeled and explained with the inclusion of a radial inflow probably generated by a bar or by spiral arms. We succeeded in detecting extraplanar diffuse ionized gas in this galaxy. At the same time, from the analysis of position-velocity diagrams, we found some evidence that the extraplanar gas could lag in rotation velocity with respect to the midplane rotation.

Kinematic Measurements in Spiral Galaxies 2 Velocity fields and their broad interpretation

2004

In this article we first give a brief, historically based, survey of kinematic observations, essentially of rotation curves of spiral galaxies, produced as techniques have advanced and new wavelength ranges have opened up. We then describe the basic inferences from kinematic measurements relevant to galactic structure: the rotational velocity and the velocity dispersion in gas and stars, and how these are made. This is followed by a selection of observations of individual galaxies, picked to illustrate how structural components: bulges, discs, lenses and bars, can be detected and analyzed kinematically as a complement to, or even a substitute for surface photometry. A further section shows how two dimensional kinematic observations of galaxies are even more powerful than one dimensional long–slit optical observations. This is illustrated by Fabry–Pérot mapping of NGC 1530 in Hα, from which we can clearly detect streaming motions in the arms, high velocity flows on either sides of th...