The distances of supernova remnants Kes 69 and G21.5−0.9 from H i and 13CO spectra.

We obtain new H i and 13CO images around supernova remnants Kes 69 and G21.5−0.9. By comparing H i spectra with 13CO emission spectra, we significantly revise the kinematic distance for Kes 69 to ∼5.5 kpc, which was 11.2 kpc, and refine the kinematic distance for G21.5−0.9 to ∼4.8 kpc. For Kes 69, the highest velocity of absorption is ∼86 km s−1 and a prominent H i emission feature at ∼112 km s−1 has no respective absorption. These new results suggest that Kes 69 is associated with a newly detected extended 1720-MHz OH maser at velocity of ∼85 km s−1 that originates from within the bright southern radio shell of Kes 69. For G21.5−0.9, the highest velocity of absorption is ∼67 km s−1. The H i absorption spectra of the nearby bright source PMN J1832−1035 and Kes 69 show a common absorption feature at velocity of ∼69 km s−1, which is not seen for G21.5−0.9. The resulting velocity of ∼68 km s−1 gives the best distance estimate of ∼4.8 kpc for G21.5−0.9 and associated young pulsar J1833−1034. [ABSTRACT FROM AUTHOR]