The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The two-fold disc-wide symmetry of spiral arms is generally attributed to density waves. Densisty wave theory can also explain a modulation of the star formation pattern along the arms according to the radial relation of the site with respect to the density-wave resonances. The degree of two-fold symmetry is reduced by the presence of a bar component. This is attributed to the increased radial mixing...
The relative tangential force amplitude provides an useful measure for the barassociated gravitational perturbation in galaxies. However, the estimation of gravitational field from near-IR images involves several uncertainties. Some of these uncertainties, as well as our current efforts in analyzing the effects of image noise and the artificial bulge stretch are summarized, illustrated by examples...
The properties of bars in S0 galaxies and early-type spirals is only beginning to be explored. This paper discusses some preliminary results on maximum relative gravitational bar torques and relative Fourier intensity amplitudes in SB0 and SB0/a galaxies and how these compare with similar quantities estimated for spirals.
Bar fractions and bar strengths are compared for active and non-active galaxies using a sample of 180 galaxies from the Ohio State University Bright Galaxy Survey (OSUBGS). The identification of bars and calculation of the perturbation strengths are made using Fourier techniques. We found that bars in AGNs are massive, but have weak perturbation strengths due to dilution of forces by massive bulges...
It is assumed that the two-fold disc-wide symmetry of spirals is caused by density waves, but also the potential of a bar component may have a significant influence on structural properties. The strength of the bar component appears to be anti-correlated with the degree of symmetry of star-forming regions in the spiral arms (Rozas et al., 1998). We present new results of R and Hα surface photometry...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.