Testing the distance duality relation using Type Ia supernovae and ultracompact radio sources

We test the possible deviation of the cosmic distance duality relation D-A(z)(1 + z)(2)/D-L(z) equivalent to 1 using the standard candles/rulers in a fully model-independent manner. Type Ia supernovae are used as the standard candles to derive the luminosity distance D-L(z), and ultracompact radio sources are used as the standard rulers to obtain the angular diameter distance D-A(z). We write the deviation of distance duality relation as D-A(z)(1 + z)(2)/D-L(z) = eta(z). Specifically, we use two parametrizations of eta(z), i.e. eta(1)(z) = 1 + eta(0)z and eta(2)(z) = 1 + eta(0)z/(1 + z). The parameter eta(0) is obtained using the Markov chain Monte Carlo methods by comparing D-L(z) and D-A(z) at the same redshift. The best-fitting results are eta(0) = -0.06 +/- 0.05 and -0.18 +/- 0.16 for the first and second parametrizations, respectively. Our results depend on neither the cosmological models nor the matter contents or the curvature of the Universe.