Reply To: Request for data

[Ken Whight]

Hi Andy,
Sorry for the delay in replying but we’ve been on grandparent half-term duties and four 3 to 7 years old’s don’t leave you with much spare time or energy!
I (think I) only have to compare the depth of absorption to the local continuum level and so don’t need to worry about response correction. I do however need to have a good i.e. not too noisy, continuum level and an accurate dark level the latter of which I obtain by subtracting the signal from a neighbouring stripe of sky. At Hbeta my normalised continuum level noise is about 0.05 so not too bad.
While I work on restoring my data gathering abiltiy I plan to predict the depth of absorption expected for the Sodium D lines over a range of (hydrogen) relative concentrations.
Regards
Ken