Kinematics modeling of molecular gas in NGC 3100

This thesis is part of a project aimed at providing a comprehensive study of different galaxy components in the core of radio-loud ETGs, and look for kinematical signatures of feeding/feedback loops that can be causally related to the presence of radio jets. For this purpose, a volume limited (z < 0.03) sample of 11 radio galaxies was selected. This sample is the target of VLT/VIMOS (warm gas and stellar components) and ALMA (molecular gas). This thesis inquires into the kinematics of molecular gas in the centre of one of the sources in the sample: NGC 3100, a FRI radio galaxy hosted by a S0 galaxy at redshift z = 0.0088. NGC 3100 was observed with APEX at 230 GHz and showed a CO(2-1) line profile (double-horned) consistent with the presence of a rotating disk. The inner region of NGC 3100 was then imaged with ALMA. As part of this thesis, ALMA data was reduced and a data cube was obtained with a beam of 1.01''x0.73'', where a CO(2-1) 230-GHz line was clearly detected. The ALMA radio continuum data, revealed the inner part of the radio jets, entirely consistent with those imaged at similar resolution with the VLA. A full analysis of the CO(2-1) line emission was made through the integrated intensity map and the integrated velocity map. The mass of the molecular gas resulted in M = 1.85 +/- 0.4 x 10^8 M_sun, consistent with what found with APEX. The CO map was compared with the distribution of dust in the inner region of the host galaxy. A nice overlap was found for the structures detected in both images. The molecular gas disk shows a complex kinematics, with some warps in the velocity field. Two programs were used to model the disk: TiRiFiC and 3D-Barolo. The comparison of their results was helpful to better understand the kinematics of the gas. The modelling confirmed initial guesses about the inclination and the position angle of the gas disk, and allowed us to derive purely rotational velocity fields as well as fields including non-circular motions.