Constructing a Tully-Fisher relation for SAMI galaxies.

The following was published on the undergraduate research experience page of Astro Bites, a daily literature journal summarizing new astrophysical research posted to astroph/arXiv. It can be read online here. It is a short summary of my research under the guidance of Prof. Jeremy Mould, CAS, Swinburne Institute of Technology, Mel, Aus on constructing a Tully-Fisher relation for galaxies observed by the SAMI survey.

You can read further on my research experience here

The goal of the SAMI survey is to observe galaxies using an IFS instrument and understand the galactic kinematics better. As part of my project with Prof. Jeremy Mould at CAS, Swinburne, we took a different direction and constructed a Tully-Fisher (TF) relation for the SAMI galaxies. The SDSS r, i & z band absolute magnitudes were used and the rotational velocities were extracted from H alpha emission lines in the IFS spectra (using in-house codes). Further, having constructed the TF relation, we intend to extend it into the third dimension using sigma/V_c as a dynamical parameter. Refer to C. Tonini et al. (2014) as to why sigma/V_c is considered appropriate in characterizing hierarchical assembly and to expand the TF relation into a three-dimensional manifold.

Interestingly, while studying the galaxy spectra, we observed galaxies with double-horned H alpha emission profiles - commonly found in HI observations of galaxies. This peculiar profile is observed in luminous galaxies with large rotational velocities which makes the H alpha emission from the left and right halves of the galaxy (from an observational point of view) strongly doppler shifted about the central value.