Do central compact objects have carbon atmospheres?
Abstract
An understanding of the chemical composition of central compact object (CCO) atmospheres is necessary in order to measure their fundamental physical properties. It has been proposed, based on X-ray spectral modeling, that the CCOs in the Cassiopeia A and G353.6-0.7 supernova remnants have uniform-temperature carbon atmospheres. Here, we show that a single-temperature carbon atmosphere model is capable of fitting the spectra of at least seven of the eight currently known central compact objects, with reasonable values of their radii resulting. However, sincetwo of these CCOs are known from their pulsations to have more complex, multi-temperature surfaces, the good fits of their spectra to a single-temperature carbon atmosphere must be a coincidence. This result argues that spectral modeling of a phase-averaged spectrum alone is insufficient evidence that a neutron star has a carbon atmosphere.
- Publication:
-
AAS/High Energy Astrophysics Division #16
- Pub Date:
- August 2017
- Bibcode:
- 2017HEAD...1610928A