A Supernova Remnant Counterpart for HESS J1832-085
Haberl, F.; Filipović, M. D.; Pühlhofer, G.; Sasaki, M.; Fukui, Y.; Leahy, D.; Sano, H.; Burton, M.; Ruiter, A. J.; Seitenzahl, I. R.; Hurley-Walker, N.; Hancock, P. J.; Rowell, G. P.; Maxted, Nigel I.; Bojičić, I.; Panther, F.; Wong, G. F.; Braiding, C.; Tian, W.; Su, H.; Cui, X.
Australia, Germany, United Kingdom, Japan, China, Canada
Abstract
We examine the new Galactic supernova remnant (SNR) candidate, G23.11+0.18, as seen by the Murchison Widefield Array radio telescope. We describe the morphology of the candidate and find a spectral index of -0.63 ± 0.05 in the 70-170 MHz domain. Coincident TeV gamma-ray detection in High Energy Stereoscopic System (HESS) data supports the SNR nature of G23.11+0.18 and suggests that G23.11+0.18 is accelerating particles beyond TeV energies, thus making this object a promising new cosmic-ray hadron source candidate. The remnant cannot be seen in current optical, infrared and X-ray data sets. We do find, however, a dip in CO-traced molecular gas at a line-of-sight velocity of ∼85 km s-1, suggesting the existence of a G23.11+0.18 progenitor wind-blown bubble. Furthermore, the discovery of molecular gas clumps at a neighboring velocity toward HESS J1832-085 adheres to the notion that a hadronic gamma-ray production mechanism is plausible toward the north of the remnant. Based on these morphological arguments, we propose an interstellar medium association for G23.11+0.18 at a kinematic distance of 4.6 ± 0.8 kpc.