Kinematics of the Isolated Luminous Infrared Galaxy CIG 993

Abstract

Abstract We present scanning Fabry–Perot interferometric observations of CIG 993, which is an apparently isolated luminous infrared galaxy that also exhibits luminous blue compact and Wolf–Rayet galaxy features, and which also has a high star formation rate. Our high-resolution observations of the Hα emission line allowed us to derive the radial velocity field (VF), the velocity dispersion σ, and the residual VFs of the galaxy. This galaxy exhibits several kinematical components. On the one hand, the velocity gradients detected on the VF can be associated with a rotating disk, which is in contrast to previous results with less spectral resolution. However, the VF, the σ and residual VF show significant deviations from circular motions in the central part of the galaxy that matches a region with high number of Wolf–Rayet and O stars, which is coincident with the blue luminous component of the galaxy. We find narrow and broad velocity components for the ionized gas in the central part of the galaxy. The broad component is evidence of a central outflow related with the ongoing burst of stellar formation. The morpho-kinematical analysis of the galaxy indicates we are only seeing the brightest parts of the galaxy, which correspond to the bulge, a central bar and the beginning of the disk. We believe that CIG 993 is a disk galaxy that harbors important star-forming processes, which are most likely caused by a relatively recent interaction. This could imply that small encounters can change the global characteristics of a galaxy without disturbing the main rotation disk motion or the morphology of the galaxy.