The central region of the enigmatic Malin 1

Abstract

Malin 1, being a class of giant low surface galaxies, continues to surprise us even today. The HST/F814W observation has shown that the central region of Malin 1 is more like a normal SB0/a galaxy, while the rest of the disk has the characteristic of a low surface brightness system. The AstroSat/UVIT observations suggest scattered recent star formation activity all over the disk, especially along the spiral arms. The central $$9 $$ 9 ′ ′ ( $$\\sim 14\\,\\hbox {kpc}$$ ∼ 14 kpc ) region, similar to the size of the Milky Way’s stellar disk, has a number of far-UV clumps—indicating recent star-formation activity. The high resolution UVIT/F154W image reveals far-UV emission within the bar region ( $$\\sim 4\\,\\hbox {kpc}$$ ∼ 4 kpc )—suggesting the presence of hot, young stars in the bar. These young stars from the bar region are perhaps responsible for producing the strong emission lines such as H $$\\alpha $$ α , [O ii ] seen in the SDSS spectra. Malin 1B, a dwarf early-type galaxy, is interacting with the central region and probably responsible for inducing the recent star-formation activity in this galaxy.