59 A distant radio galaxy, 8C 1435+63, has a redshift of z = 4.25. Assume WMAP values for this problem: (4) How old was the universe at this redshift? Express your answer both in terms of years and as a fraction of the present age of the universe. (b) What is the present proper distance (in Mpc) to 8C 1435+63? (c) What was the proper distance (in Mpc) to 8C 1435+63 when its light was emitted? (d) What is the luminosity distance to 8C 1435+63? What is the angular diameter distance to 8C 1435+63? The angular diameter of the nucleus of 8C 1435+63 is about 5". What is the linear diameter of the galaxy (in units of kpc)? (g) Suppose the galaxy's redshift were 1. What would its linear diameter be [using the same angular diameter as in part (d)]? Further information about 8C 1435+63, which may be the progenitor of a cD elliptical galaxy, can be found in Spinrad, Dey, and Graham (1995).