Table 1 An explicit listing of the possible separate PUI populations for the different regions illustrated in Fig. 4

<8 AU (within ionization cavity)

Standard MHD model—PUIs essentially treated as test particles

~8 AU to HTS (i.e., beyond ionization cavity)

Multi-component model

Interstellar PUIs created in solar wind (\(T \le 1\)  keV, \(n_p \sim 0.05 {-} 0.2 n_i\)) \(+\) thermal plasma (protons and electrons)

IHS

Multi-component model

Three PUI populations:

1) Interstellar PUIs transmitted across HTS without reflection (\(T \sim 1\)  keV, \(n_p \sim 0.18 n_i\))

2) Interstellar PUIs reflected and then transmitted at HTS (\(T \sim 6\) –7 keV, \(n_p \sim 0.02n_i\))

3) Interstellar PUIs created in IHS (\(T \sim 50\)  eV, \(n_p \sim 0.015n_i\)) + thermal plasma (\(T \sim 16\) eV, \(n_i \sim 0.005\)  cm\({}^{-3}\))

Multi-component model

 1) Retain 1) + 2) and incorporate 3) in thermal plasma model (i.e., neglect heat flux for \(T \sim 50\)eV PUIs)

 2) Combine models 1) and 2) and incorporate 3) in thermal plasma model

VLISM

Multi-component model

Solar wind PUIs created in VLISM (\(T \sim 200\)  eV, \(n_p \sim 5 \times 10^{-5}\)  cm\({}^{-3}\)) + thermal plasma (\(T \sim 0.65\) eV, \(n_i \sim 0.15\)  cm\({}^{-3}\))