G156.2+5.7: SN 1006's older cousin
Abstract
We report on the results of an analysis of the hydrodynamic properties of the supernova remnant G156.2+5.7. The models of Truelove and McKee (1999) are constrained by the observed amount of thermal X-ray emission, the measured temperature of the forward-shocked electrons, the inferred location of the reverse shock, and the observed amount of non-radiative Balmer line emission. The results suggest that the remnant is expanding into a low-density environment at a distance of at least 0.6 kpc. We review several clues that suggest the remnant was produced by a Type Ia supernova, which when combined with the other hydrodynamic constraints, implies that G156.2+5.7 is 2.6-15 kyr old, is 0.7-1.7 kpc from Earth (i.e. between Earth and the Perseus arm), and is surrounded by material with a hydrogen density of 0.046-0.075 cm-3. These properties are consistent with the remnant having a low radio surface brightness with a highly-ordered and highly-polarized, tangential magnetic field that is inclined by 60-70 degrees relative to the Galactic plane. However, the inferred density and age are not consistent with the fitted value of the ionization age, which may indicate that the momentum distribution of the electrons is not a Maxwell-Boltzmann distribution, but instead includes a high-energy, non-thermal tail.
- Publication:
-
AAS/High Energy Astrophysics Division #15
- Pub Date:
- April 2016
- Bibcode:
- 2016HEAD...1511811A