The locations of the Quasars surrounding the galaxy and the redshifts associated with them were obtained from a research paper entitled NGC 3628: Ejection Activity Associated with Quasars, page 2, Fig. 1.

Distances were determined using the a Hubble Constant of 72 km/sec/Mpc, Omega_Matter of .3, and Omega_Lambda of .69.  The distances were calculated using the Osservatorio Astronomico di Bologna Cosmological Calculator.  The distances calculated are approximate due to the value of the constants used.  These constants change as additional research is conducted on the expansion of the universe, the mass of the universe, and the amount of total energy of the universe.