The histograms for the FWHM of the Pa Beta and Br Gamma emission lines are shown in Figure 5.3.
The lines are very broad, with the Pa Beta lines having a mean FWHM of
km/s
and a median of 190 km/s
and with the Br Gamma
lines
having a mean FWHM of
km/s
and a median of 200 km/s
. Both lines have a similar
distribution of FWHM.
Figure 5.3: Pa Beta and Br Gamma FWHM
Histograms. The Pa Beta data is displayed in the upper panel and the Br Gamma
data on the lower.
Such broad lines can result from the dynamics of the region where they originate or from radiative transfer effects that broaden the line. This will be further discussed in Chapter 6.