Hydrogen line profiles

Raw data from the Galactic plane, latitude 0, from longitude 20 to longitude 94 is available here.

The data was collected using a Spectra Cyber spectrometer. The telescope uses a 3.7m reflector built on the alt/az mount described here.

The individual data files are ascii text files with a header line and 400 lines of data.

Each line of data is 5 kHz step from 1419405.750kHz to 1421400.750kHz.

I have no instruments capable of verifying the accuracy of the frequency.

The header line consists of 's' for spectrometer, date, time, (GMT), 1 second integration, H +/- 1000kHz and 5 times dc amplification.

Plotting the raw data looks like top right.

It can be seen that there is a distinct curve in the baseline of the data and this can be removed by fitting a polynomial curve to the baseline and subtracting giving middle right.