CTIO Hydra View Window

HYDRA CTIO

NEWS:

Download the latest simulator (includes hydraassign):
Solaris version -- Linux version (updated October 2001)

Get the latest concentricities file:

concentricitieslarge --for use with the 400m Bench Schmidt camera (updated December 16, 2002).
alternating_concentricities --for use with smaller numbers of targets or the Air Schmidt camera (emergency backup only, updated March 2000)

(NB! Be sure that ECCENFILE in .fiborg points to the right concentricities file)

"Hydra-CTIO" is a multi-object, fiber-fed spectrograph which is used with the CTIO Blanco 4m telescope. The positioner is mounted at the Cassegrain focus, with the fibers feeding a bench spectrograph located in a room below the dome floor. Hydra-CTIO will ultimately be the principal Cassegrain instrument on the 4m telescope.

The instrument was commissioned during October-December, 1998. It was first used with an Air Schmidt camera and Loral CCD. In its current incarnation, Hydra-CTIO uses a 400mm camera and SITe 4Kx2K detector. The new camera/detector combination offers superior resolution and lower dark current compared to the old Air Schmidt. The Loral Air Schmidt is no longer in use.

Hydra-CTIO is similar to Hydra-WIYN, now in routine use at KPNO. A number of upgrades have been made to Hydra-CTIO. Its salient parameters can be summarized as follows:

138 large (300u/2.0" dia.) fibers
Spectral coverage 330-1100nm
Positioning time ~20 minutes (~8 sec./fiber)
40 minute field
Minimum fiber-fiber distance 25"
Atmospheric Dispersion Compensation
Slit plates for higher spectral resolution: spectral resolution to ~50000 with the 400mm camera and the narrowest slit plates