Snowden and coworkers have presented a model for the ¼ keV soft X-ray diffuse background in which the observed flux is dominated by a \sim 10 ^ { 6 } K thermal plasma located in a 100–300 pc diameter bubble surrounding the Sun , but has significant contributions from a very patchy Galactic halo .
Halo emission provides about 11 % of the total observed flux and is responsible for half of the H i anticorrelation .
The remainder of the anticorrelation is presumably produced by displacement of disk H i by the varying extent of the local hot bubble ( LHB ) .
The ROSAT R1 and R2 bands used for this work had the unique spatial resolution and statistical precision required for separating the halo and local components , but provide little spectral information .
Some consistency checks had been made with older observations at lower X-ray energies , but we have made a careful investigation of the extent to which the model is supported by existing sounding rocket data in the Be ( 73–111 eV ) and B bands ( 115–188 eV ) where the sensitivities to the model are qualitatively different from the ROSAT bands .
We conclude that the two-component model is well supported by the low-energy data .
We find that these combined observations of the local component may be consistent with single-temperature thermal emission models in collisional ionization equilibrium if depleted abundances are assumed .
However , different model implementations give significantly different results , offering little support for the conclusion that the astrophysical situation is so simple .