Let us examine a fictitious but representative PDF you might find: (MNRAS, 2024).
For researchers and advanced amateurs, the following documents (available via arXiv or journal websites) provide the full analysis: white dwarf 137 pdf hot
The PDF-format spectral analysis (e.g., from the Montreal White Dwarf Database) shows broadened helium absorption lines (He I 4471Å, He II 4686Å) due to high pressure and temperature broadening. The presence of He II lines indicates that some helium is collisionally ionized, requiring temperatures above 60,000 K. Let us examine a fictitious but representative PDF