A dynamical analysis of the massive cluster VC04 in the Vela supercluster

Project Description:

We are conducting a campaign to study and learn more about the properties of the Vela Supercluster (VSCL) located behind the Milky Way at cz~18000 km/s. The VSCL is an extended structure across the Zone of Avoidance (ZoA), which may add an appreciable contribution to the residual bulk flow generated at distances beyond cz~16000 km/s. We have studied five galaxy clusters using deep NIR (JHK_s) observations (with IRSF) which are complete to extinction-corrected absolute magnitude of M_{Ks}^o<-21.5 mag at the distance of the VSCL ( ~2.5 mag below M_K*), within the clustercentric radius of r_c<1.5 Mpc ( ~70% of the Abell radius. VC04 is the richest known galaxy cluster in the VSCL, for which we obtained 90 new spectroscopic redshifts of galaxies with SALT. The iso-density contour map (two-dimensional test) of VC04 and the spectroscopic information of galaxies suggest VC04 to be a not yet fully relaxed cluster. The brightest galaxy of VC04 lies outside of r<0.5 Mpc, within a small density enhancement. We would like to perform a dynamical analysis on VC04 using a three-dimensional test to analyse its structure. The Dressler–Shectman (DS) delta-test (Dressler & Shectman 1988) is a particularly powerful and frequently used method to quantify substructure (using velocity and positional information). In this projects the student will measure the velocity dispersions of galaxies with known redshift measurements using their optical spectra and will perform the DS delta-test on the VC04 cluster to probe substructures in this cluster.

Research Area:

Astronomy

Project Level:

Honours

This Project Is Offered At The Following Node(s):

(UCT)

Special Requirements:

The student must be familiar with Python programming and having experience with IRAF is desirable.