The Distance of the SNR Kes 75 and PWN PSR J 1846 - 0258 System

The supernova remnant (SNR) Kes 75/PSR J1846-0258 association can be regarded as a certainty due to the accurate location of young PSR J1846-0258 at the center of Kes 75 and the detected bright radio/X-ray synchrotron nebula surrounding the pulsar. We provide a new distance estimate to the SNR/pulsar system by analyzing the HI and 13 CO maps, the HI emission and absorption spectra, and the 13 CO emission spectrum of Kes 75. That there are no absorption features at negative velocities strongly argues against the widely-used large distance of 19 to 21 kpc for Kes 75, and shows that Kes 75 is within the Solar circle, i.e. a distance d <13.2 kpc. Kes 75 is likely at a distance of 5.1 to 7.5 kpc because the highest HI absorption velocity is at 95 km/s, and no absorption is associated with a nearby HI emission peak at 102 km/s in the direction of Kes 75. This distance to Kes 75 gives a reasonable luminosity of PSR J1846-0258 and its PWN and also leads to a much smaller radius for Kes 75, so the age of the SNR is consistent with the spin-down age of PSR J1846-0258, confirming this pulsar as the second-youngest in the Galaxy.