The revised distance of supernova remnant G15.4+0.1

We measure the distance to the supernova remnant G15.4+0.1 which is likely associated with TeV source HESS J1818-154. We build the neutral hydrogen (Hi) absorption and 13CO spectra for supernova remnant G15.4+0.1 by employing data from the Southern Galactic Plane Survey (SGPS) and the Hi/OH/Recombination line survey (THOR). The maximum absorption velocity of about 140 kms−1 constrains the lower limit of its distance to about 8.0 kpc. Further, the fact that the Hi emission feature at about 95 km s−1 seems to have no corresponding absorption suggests that G15.4+0.1 likely has an upper limit for distance of about 10.5 kpc. The 13CO spectrum for the remnant supports our measurement. The new distance provides revised parameters on its associated pulsar wind nebula and TeV source.