Abstract Details

Name: K ADITYA
Affiliation: Indian Institute of Science Education and Research, Tirupati
Conference ID: ASI2021_437
Title : GMRT HI 21cm observations of the superthin galaxy FGC1440
Authors and Co-Authors : K Aditya(Indian Institute of Science Education and Research, Tirupati), Peter Kamphuis (Ruhr-Universität Bochum) & Arunima Banerjee (Indian Institute of Science Education and Research, Tirupati)
Abstract Type : Poster
Abstract Category : Extragalactic Astronomy
Abstract : Superthin galaxies are low surface brightness, bulges disc galaxies, characterised by optical discs with strikingly high values of planar-to-vertical axes ratios ($>$ 10), the physical origin and evolution of which continue to be a puzzle. We present GMRT HI 21cm radio-synthesis observations of FGC1440, an extremely thin disc galaxy with an axial ratio $a/b$ equal to 20.4, with a spectral resolution of 1.7 km/s (8.138kHz), a spatial resolution of 15.9” × 13.5” and an rms equal to 1.01mJy/beam. We construct a three-dimensional tilted ring model of the HI distribution to derive the kinematic properties of FGC 1440 using Fully automated Tirific (FAT). Our results indicate that FGC 1440 has a slowly rising rotation curve with an asymptotic rotational velocity equal to 142 kms$^{-1}$, an inclination equal to 88.5 degrees and position angle of 53.6 degrees. The HI distribution is asymmetric on the approaching and the receding sides. By manually comparing the PV diagrams at different offsets, we find that the HI velocity dispersion lies in between 5 and15 kms$^{-1}$, and the scale height corresponding to the HI disc less than 1.8 kpc. Further, the galaxy might possibly host a line of sight warp.