| Abstract : | The existence of a tangible relationship between relativistic jets in active galactic nuclei (AGNs) and the morphology of their host galaxies has often been suggested. In particular, it is widely believed that powerful jets are hosted in elliptical galaxies, harboring supermassive black holes (SMBH, $M_{BH} > 10^{8} M_{sun}$). However, fully developed relativistic jets, capable of emitting gamma-ray photons are observed in a few gamma-ray detected Narrow-line Seyfert 1 galaxies (gamma-NLSy1s), harboring lower black hole mass ~10$^{6}$ to ~10$^{7} M_{sun}$, and are usually hosted in spiral/disc galaxies. This challenges the theoretical scenarios of jet formation and casts doubts on the connection between relativistic jet production, SMBH mass, and the host galaxy, in the case of gamma-NLSy1s. To resolve this tension of galaxy types in gamma-NLSy1s, we have selected a sample of gamma-NLSy1s having redshift ~< 0.6 with their intra-night optical variability study has already been carried out. This has resulted in a sample of 11 gamma-NLSy1s. The host galaxy imaging of these galaxies in SDSS filters g and r with 3.6m Devasthal Optical Telescope (DOT) of Aryabhatta Research Institute of Observation Sciences, India has revealed the spiral and/or disc galaxy-type morphologies for all the observed sources using the 2D surface brightness model-fitting code GALFIT. Furthermore, based on the differential light curves of these sources, it is found that about half of the sources are also showing minute-like variability. The spiral and/or disc galaxy-type morphologies in gamma-NLSy1s suggest that the launching of relativistic jets in AGNs is independent of their host galaxy types. |
