UIST logo

Instrument Apertures and Foci

UIST logo

Apertures
(Last update - 3 October '03)
 
Mode Aperture for telescope, arcsec
Imaging 0.12 -6.04 -2.14
Imaging 0.06 -2.66 -0.32
Spectroscopy 7.30 1.10
IFU 1.50 -0.00
X-disp Spec -- --
Polarimetry 24.09 0.01
Notes:
* All values redone after new centre-of-rotation determined
1. Use the same aperture for imaging-polarimetry and spectro-polarimetry (values tuned to the latter).
2. The arcsec values are simply the mm values x -1.524
3. The first value is E-W, the second N-S, so in the rotated UIST frame the first value is along the slit (up and down, or in Y in pixels - see below)
4.The difference between apertures should be fixed (so strictly speaking we only need to measure onne, or maybe two for the two camera plate scales). Approximate offsets are: 
 - Spectroscopy = Imaging(0.12arcsec) + 13.2, Imaging(0.12arcsec) + 2.6 

 - IFU          = Imaging(0.12arcsec) +  7.5, Imaging(0.12arcsec) + 2.0 

 - Polarimetry  = Imaging(0.12arcsec) + 31.2, Imaging(0.12arcsec) + 3.7

 

Location on array
Use these numbers for imaging acquisition
(Last update - 4 April '03)
 
Mode Location on array, (x,y)
Spectroscopy, 1 pix slit 506.4 590
Spectroscopy, 2 pix slit 505.2 590
Spectroscopy, 4 pix slit 502.2 590
Spectroscopy, 5 pix slit 501.5 590
Spectroscopy, 7 pix slit 507.7 590
X-disp Spectros, 3 pix slit 503.5 5412
X-disp Spectros, 5 pix slit 503.4 5412
X-disp Spectros, 7 pix slit 504.0 5412
Spec-Pol, 2 pix slit 510.6 7402
Spect-Pol, 5 pix slit 511.6 7402
IFU 499 540
Imaging, 1024x1024 480 480
Imaging, 512x512 224 224
Imaging Polarimetry 511 7403

Notes:
1. Centre of rotation is at (x,y)=.... (ask Russell)
2. Rough y-axis centre of each cross-dispersed 20" slit, or the top spec-pol slit, on array.
3. For polarimetry, in imaging mode WITHOUT the prism in the beam, putting a star on the above location will put the star in the center of the top slit in the 5-pixel spec-pol-mask (or the centre of the top aperture in the imaging-pol-mask).

 

Additional offsets during source acquisition
(Last update - 4 April '03)
 
Grism Filter used Additional offset
by TSS at telescope
IJ J-spec right 0.67 arcsec
Short_K B2 left 0.05 arcsec
Long_K B2 left 0.9 arcsec
KL B2 left 0.9 arcsec
Short_L 3.4cont left 0.1 arcsec
Long_L BrA right 0.17 arcsec
M BrA left 0.15 arcsec

 

Telescope foci
(Last update - 3 September '03)
 
Mode Focus, mm
Spectroscopy 0.86
Imaging, 0.12 0.86
Imaging, 0.06JHK 1.08
Imaging, 0.06LM 0.78
IFU 1.04*
Pol 0.93*
Notes:
The 0.12" imaging and spectroscopy foci should be about the same.
The 0.06"JHK focus should be MORE than the 0.12" focus by about 0.2mm.
The 0.06"LM focus should be LESS than the 0.12" focus by about 0.05mm.
The IFU focus should be MORE than the 0.12" focus by about 0.2mm
The Pol focus should be MORE than the 0.12" focus by about 0.05mm
*Estimated values

Previous Values (prior to date):
20031003
20030903
20030731
20030424
20030403
20030131
20030106
 

Previous: Grism Wheels | Up: UIST Engineering | Next: UIST Engineering

Last Modification Date: 3 October 2003
Last Modification Author: Chris Davis