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Instrument Apertures and Foci

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History
- UIST off scope in March 2003 to replace grisms and filters
- UIST off scope (cryogenic/vacuum problems) from Dec '03 until 2 April '04.

Apertures
(Last update - 19 April '04)
[UIST off scope prior to this date for long period - see above]
 
Mode Aperture for telescope, arcsec
Imaging 0.12 -6.77 -2.62
Imaging 0.06 - -
Spectroscopy +6.65 -0.75
IFU +0.69 -1.07
X-disp Spec -- --
Polarimetry +24.43* +1.08*
Notes:

1. Use the same aperture for imaging-polarimetry and spectro-polarimetry.
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
*Estimated values

 

Location on array
Use these numbers for imaging acquisition AND aperture measurements
(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 (0.12") 480 480
Imaging, 1024x1024 (0.06") 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 the top spec-pol slit on the 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. (E-beam image of star will then be on pixel 510,823; o-beam on 510,655 [for H-band]).
Apertures highlighted in red to be measured on QA night, please

 

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 0.90 arcsec
KL B2 left 0.90 arcsec
Short_L 3.4cont left 0.10 arcsec
Long_L BrA right 0.17 arcsec
M BrA left 0.15 arcsec

PLEASE NOTE: UPICK automatically applies the above offsets. TSSs do not have to adjust the source position after imaging acquisition in the thermal (this is why upick puts the star on a slightly different pixel than is listed earlier on this page).

UIST Focii

The plot below shows fine-focus measurements taken on QA nights. Note that not all focii are measured on a given day (so some values are missing). The dates marked "UIST off scope" indicate when the instrument was physically taken off the telescope for a period of time. Thus, after one of these periods values might be expected to change...

  UIST focii

Pink - 0.12imaging/Spec focii; Yellow - 0.06JHK focii; Light Blue - 0.06LM focii; Purple - IFU focii; Brown - Pol focii.

Current values being used at the telescope are given in the table below

 

Telescope foci
(Last update - 2 April '04)
 
Mode Focus, mm
Spectroscopy 0.56*
Imaging, 0.12" 0.56
Imaging, 0.06"JHK 0.75*
Imaging, 0.06"LM 0.54*
IFU 0.71*
Pol 0.60*
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 0.19mm.
The 0.06"LM focus should be LESS than the 0.12" focus by about 0.02mm.
The IFU focus should be MORE than the 0.12" focus by about 0.15mm
The Pol focus should be MORE than the 0.12" focus by about 0.04mm
*Estimated values

 

Previous Values (prior to date):
20040402
20031220
20031124
20031003
20030903
20030731
20030424
20030403
20030131
20030106
 

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Last Modification Date: 19 April 2004
Last Modification Author: Chris Davis C.davis at jach.hawaii.edu