International Congress of Engineering and Natural Sciences Studies, Ankara, Turkey, 7 - 09 May 2021, pp.82
Molecular clouds (MCs) are the places for stars to be born and die. It is necessary to obtain
multiple emission lines to study the physics and kinematics of the MCs better. Carbon monoxide
(CO), the second most abundant molecule in the interstellar medium, is widely used to probe the star-forming
gas clouds. In this study, we probe the physics of the gas and dust across the disc of the
nearby spiral galaxy NGC 7331. Using the literature CO data, we selected 14 regions over the galaxy.
12CO(1-0) intensities, far-ultraviolet (FUV) and 24𝜇𝑚 flux density were obtained for all the regions.
CO intensities, gas mass, gas surface density, 24𝜇𝑚-to-FUV flux ratio (i.e. the extinction) increase up
to about 40" (≈ 3 kpc) from the centre and then start to decrease. There is a positive correlation
between many parameters studied, such as between the molecular gas mass and the extinction. Our
results indicate that the regions on the eastern side of the disc show some differences in the physical
parameters compared to the regions on the western side. This indicates that the star formation history
and physical properties of the interstellar medium could be different on either side of the disc.