In Brief
CYCLOPS is a Cassegrain fibre-feed for the UCLES spectrograph. It provides better throughput than the current Coude mirror train, while also reformatting an approximately 2 arcsec diameter aperture on the sky into an 11 x 0.6 arcsec pseudo-slit at the entrance of the UCLES spectrographs. It is known that for a wavelength configuration centred on 5000-6000A that CYCLOPS delivers 30% more photons at 50% higher resolution than the equivalent 31 l/mm set-up with a 1 arcsec slit.
Note that CYCLOPS can not be used with UHRF.
More detailed information can be found on the CYCLOPS web page at UNSW.
Status (as of February 2011)
Prospective users should note that at the present time:
- CYCLOPS is commissioned with 12 of its originally planned 15 fibres.
- There is now no measurable flexure (< 0.1") between the instrument and guide camera.
- Slit flats (i.e. flats taken through the UCLES slit rather than the CYCLOPS fibres) are needed for processing CYCLOPS data, and can be acquired during the day wih technician assistance.
Performance Assumptions
Astronomers proposing to use CYCLOPS should note and assume the following for the purposes of preparing proposals:
- Proposers should assume as an approximate figure of merit, that the combined effect of the bundle/coude train throughput and slit/bundle aperture losses is that CYCLOPS delivers 30% more counts in 1.5 arcsec seeing than the current UCLES coude train + 1.0 arcsec slit.
- CYCLOPS delivers a fixed spectra resolution with the 79 l/mm grating of &lambda/&delta&lambda = 70000 (equivalent to a spectral FWHM of 2.55 pixels).
- Only the 79 l/mm echelle grating can be usefully used with CYCLOPS.
Astronomers interested in more details are encouraged to contact the UCLES Support Astronomer (Gayandhi de Silva, AAO, gdesliva -@- aao.gov.au) or the CYCLOPS Project Scientist (Chris Tinney, UNSW, c.tinney -@- unsw.edu.au) to further discuss their plans if they require more information.
Operational Matters
CYCLOPS cannot be interchanged with the UCLES Coude-train feed without making a top-end change. They therefore cannot be interchanged during a night, and in fact can only be interchanged subject to the AAO's usual requirements on instrument changes.
CYCLOPS can no longer be interchanged with IRIS2 during a night.
As far as the UCLES spectrograph is concerned, CYCLOPS data will be very similar to any other 79 l/mm echelle data. So data reduction will very closely follow that required with normal UCLES 79 l/mm echelle data - proposing observers should plan on using existing reduction suites for this purpose.
CYCLOPS has a slightly modified graphical user interface (GUI) compared to that currently used for UCLES (i.e. disabling the beam rotator and mirror slide), and a small additional GUI for controlling the CYCLOPS fibre flat-field, ThAr lamps and fibre vibrator. These changes are small and proposing observers can prepare by reading the documentation for regular UCLES observations.
Further Information
- The CYCLOPS web page at UNSW.
- A presentation giving an overview of the instrument and its design.
Return to UCLES instrument page
Gayandhi De Silva, AAT Technical Secretary, aatts -@- aao.gov.au