Thanks for all your comments, Everyone.
Ken: I haven't bench tested this lately but can get a rough estimation from my H alpha results of this August. If I compare the fwhm of a measured spectral line in my instrument with a spectral linewidth of the same line in the BASS2000 spectrum, I get an instrumental bandpass of ~ 0.18 Angstrom (fwhm) near H alpha for my spectrometer in the present configuration (25 micron slit, 500mmf collimator, 2400 l/mm grating, 300mmf camera lens).
Here is a comparison plot of a measured spectrum taken on August 8 and the BASS2000 spectrum.
- Ha Comparison BASS2000.png (53.13 KiB) Viewed 962 times
In this magnified view, I'm comparing the widths of a relatively isolated feature.
- Ha Comparison BASS2000 - isolated feature.png (43.97 KiB) Viewed 962 times
The BASS2000 spectrum claims a resolution of 0.01 Angstrom and I'm assuming the relation: BASS2000_fwhm^2 + Instrumental_fwhm^2 = Measured_fwhm^2 , which is strict for Gaussian profiles. From the fwhm values quoted on the last plot, the Instrumental_fwhm can be calculated to be ~0.18 Angstroms. This seems to be pretty reasonable when you observe how the images change over the course of the spectral sweep.
It's much more difficult to do this type of comparison in the uv because of the congested nature of the spectrum. Here's an example.
- CaK Comparison BASS2000.png (107.62 KiB) Viewed 961 times
Cheers, Peter.
