Abstract Details
| Name: SOUMAVO GHOSH Affiliation: IISc, BANGALORE Conference ID: ASI2016_577 Title : Effect of Dark Matter halo on spiral structures of different scales Authors and Co-Authors : Prof. Chanda J. Jog (IISc) Tarun Deep saini (IISc) Abstract Type : Oral Abstract Category : Extragalactic astronomy Abstract : Low surface brightness (LSB) galaxies are known to be dominated by Dark Matter (DM) halo, starting from the very inner radii. Hence, LSB galaxies naturally offer a place to probe the effect of DM halo on galactic dynamics. We have investigated theeffect of dark matter halo on spiral structures of different scales, using the input parameters of UGC 7321, a typical superthin, LSB galaxy. For the small-Âscale structures, we found that the dominant dark matter halo suppresses the smallÂscale spiral structures almost completely, thus providing a natural explanation to the lack of strong flocculent arms in LSB galaxies. Next we also studied global modes which we find are not much affected by DM halo, when the galactic disc is modelled as fluid. However, since these LSB galaxies reside at the edge of the voids, or in isolated places and consequently galaxy encounters are less likely to occur. Therefore, although technically, the global spiral modes are allowed in both stars only and stars embedded in DM halo , the lack of galaxy interactions makes it unlikely for the largeÂscale spiral structures to happen in real galaxies. REFERENCES: • Ghosh S. & Jog C. J., 2014, MNRAS, 439, 929 • Ghosh S., Saini T. D. & Jog C. J., 2015,in press, MNRAS, |