Abstract
Photometry and long-slit spectroscopy are presented for a sample of 6 galaxies with a low surface brightness stellar disc and a bulge The characteris ing parameters of the bulge and disc components were derived by means of a two-dimensional photometric decomposition of the images of the sample galaxies. Their surface-brightness distribution was assumed to be the sum of the contribution of a Sersic bulge and an exponential disc, with each component being described by elliptical and concentric isophotes of consta nt ellipticity and position angle. The stellar and ionised-gas kinematics were measured along the major and minor axis in half of the sample galaxies, whereas the other half was observed only along two diagonal axes. Spectra along two diagonal axes were obtained also for one of the objects with major and minor axis spectra. The kinematic measurements extend in the disc region out to a surface-brightness level µR � 24 mag arcsec 2 , reaching in all cases the flat part of the rotation curve. The stellar kinematics turns out to be more regular and symmetric than the ionised-gas kinematics, which often shows the presence of non-circular, off-plane, and non-ordered motions. This raises the question about the reliability of the use of the ionised gas a s the tracer of the circular velocity in the modeling of the mass distribution, in particular in th e central regions of low surface brightness galaxies.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
