Image Details
Caption: Figure 5.
Exponential wings are required. Comparison of a Gaussian×exponential model (red) and a single Gaussian profile (blue) for Hα. Uncertainties are shown as vertical lines in each spectral bin, although they are too small to be visible. The exponential model provides a far superior fit, with smoother residuals and a strongly preferred ΔBIC, highlighting the necessity of exponential wings to capture the broad-line shape.
© 2026. The Author(s). Published by the American Astronomical Society.