Paper detail

Wavelength calibration of the Hamilton echelle spectrograph

We present the wavelength calibration of the Hamilton echelle spectrograph (the Lick observatory). The main problem of the calibration arises from the fact that thorium lines are absent in the spectrum of "ThAr" hollow-cathode lamp now under the operation. On the other hand, numerous unknown strong lines are present in the spectrum. These lines was identified with titanium. We estimate the temperature of the lamp gas which permits us to calculate the intensities of the lines, and to select a large number of relevant Ti I and Ti II lines. The titanium line list for the Lick hallow-cathode lamp is presented. The wavelength calibration using this line list was made with accuracy about 0.006A.