Before proceeding to the analysis of the line profiles one should note that many spectra contain narrow absorption lines. At Pa Beta some of these lines fall on top of the hydrogen emission line changing its profile. These lines are of photospheric origin and it is desirable to get rid of them for a proper analysis of the emission line profiles. Such a procedure is possible to be carried out with the data set available. Further than that, it provides extremely useful information for the understanding of the T Tauri stars and surrounding material. This is discussed in the next chapter.
Figures 3.12 and 3.13 show respectively the Pa Beta and Br Gamma spectra of the T Tauri stars observed during the UT9512 run.. When two spectra are displayed for a given star the upper one (with continuum normalized to unity) is the result of removing the photospheric component of the spectrum and the lower one (shifted vertically so that the continuum is at about 0.6) is the spectrum before removing the photospheric component. If only one spectrum is displayed no lines with photospheric origin were identified and thence there was no photospheric component to be removed. Figure 3.14 shows the Pa Beta and Br Gamma spectra obtained during the UT9410 observing run.
Figure 3.13: Br Gamma spectra of the observed
T Tauri stars. When two spectra are shown per panel the upper one
corresponds to the star's spectrum after removal of the photospheric
component and the lower one corresponds to the star's spectrum before
removal of that component. If only one spectrum is displayed no lines
with photospheric origin were identified and thence there was no
photospheric component to be removed. Stars are ordered alphabetically.
Figure 3.14: Pa Beta and Br gamma spectra of the T
Tauri stars observed during the UT9410 observing run. The error bar for
each spectral point is also plotted. The first five panels (starting at
the top left and moving rightwards) display the Pa Beta data obtained
with stars ordered alphabetically. The remaining panels display the
obtained Br Gamma spectra also arranged alphabetically by the name of
the stars. As readily noted, the wavelength coverage for the UT9410 data
is about four times smaller than that for the UT9512 observing run.