AAOmega first night check list
This page is designed as a check list for the instrument support astronomer for the first night of a new AAOmega run. Please report any ambiguous items, or any items that should be added.
- Is the correct dichroic in AAOmega?
The AAOmega full status dialog will say X5700 or X6700. Any other value is incorrect and must be changed in order to allow correct 2dfdr data reduction.
If the dichroic has not been seated properly then the blue spectra may fall off the CCD. The red spectra will be fine since this light is in transmission. Check there are a few (10-20) blank pixels above and below the spectra, at all X values, in a blue camera flat frame.
Are all the lights off inside the spectrograph room? This includes indicator LEDS on items like the dichroic sensing system. Enter the spectrograph room, close the door and turn the lights off for a few minautes. Take a torch!
Are all the top-end lights off? The 2dF electronics racks have indicator lights. These can be left on after engineering work and should be set to the off postions.
Are the correct gratings in?
Are the cameras at the correct wavelength and blaze angle, and are the CCDs focussed?
Note, the blue camera frequently has to be moved by the day crew between observing runs. They do this to attach the vacuum pump more easily. This can leave AAOmega claiming that the camera is in position (where it was left at the end of the last run) but in fact no spectra will appear on the blue CCD while the red one is fine. Simply reconfigure the blue arm using the AAOmega gui (tdfct) as normal.
For the medium/high resolution gratings, there can be strong grating ghosts in the field. Do they cover critical features, and should the camera/grating angles be modified to move the ghost (position is quite non-linear)? One must check an arc frame and scan for the ghost.
Take some Bias frames (dome lights off) so that bad columns can be recovered and so that 2dfdr will use the best bad pixel mask.
Which version of 2dfdr is available?
The last stable general user release is available at the telescope. More powerful versions may be available, but are considered beta test versions and so should only be used by experianced users and with caution.
Which .idx file(s) will be used with 2dfdr?
Is the user aware of the issues of CVD and the configure wavelength?
For Blue data
Is the 5577A night sky line free from bad columns? This is particularly important for 580V data with the X6700 dichroic.
Do you get the 5577A sky line at all? Will you need twilight flats and/or offset skies?
Are key spectral features free from bad columns? H-beta and [OIII] are often in just the wrong place.
Is the blue arc solution correct? The blue arc solution should be examined. It needs to be perfect but can be unstable, requiring modification to the starting point via fits header keyword parameters, described in the Guide to modifying the wavelength solution.