DR. ARUNIMA BANERJEE

Some low surface brightness galaxies are known to be have extremely thin stellar disks with the vertical to planar axes ratio 0.1 or less, often referred to as superthin disks. Also, these galaxies are bulgeless i.e devoid of a central spheroidal component called the bulge which is a characteristic feature of most disk galaxies in general. Our earlier studies have shown that it is the compact dark matter halo which plays the decisive role in determining the superthin disk distribution in low-mass disks. Recent studies have indicated that the dark matter halo is also responsible in inhibiting the growth of axisymmetric/non-axisymmetric local instabilities in these superthin disks. In this talk, the speaker will discuss that although the disk is stable to local perturbations, it is unstable to the growth of global non-axisymmetric perturbations, which are responsible for the growth of bars and spiral arms in a galactic disk.