There is ample evidence that pickup ions in the inner heliosphere have two distinct sources. The first source is well identified. Interstellar neutral atoms that can penetrate deep into the heliosphere unimpeded by the solar magnetic field and become ionised by solar UV radiation, or charge exchange with solar wind. Their interstellar origin has been unambiguously identified by observations. In contrast, the nature of the second, so-called inner source, remains unclear. Previous studies suffered from very low counting statistics that did not allow to distinguish between several proposed scenarios. We have analysed data from the Charge Time-Of-Flight instrument on-board the Solar Heliospheric Observatory and found that C+ and O+ are well resolved and furthermore the counting statistics delivered by the Charge Time-Of-Flight instrument is unprecedented. Here we present short-term w-spectra of C+ and O+.

This content is only available via PDF.
You do not currently have access to this content.