TMAS Visible Light AO Instrument Observing Candidate Observing Modes
Note all numbers on this page has yet to be verified!
TMAS cameras
- Leading option
- 2 ea. Andor 5 MPix (2560 x 2160) NEO sCMOS cameras from Gregg Hallinan
- 6.5 micron pixels; Max rate = 100Hz; QE (400nm) = 0.3, QE (550nm) = 0.57, QE (900nm) = 0.14
- Backup options
- Andor 1 MPix (1024 x 1024) 888 iXon EMCCD camera from Christoph Baranec (with 'BV' quantum efficiency option)
- 13 um pixels; Max rate = 10Hz (full frame); QE (400nm) = 0.6; QE (550nm) = 0.96, QE (900nm) = 0.48
- CCD21 (1024 x 1024) custom former DBSP red channel camera
- ? um pixel; Max rate = Slow; Mature science GUI; pretty good CCD QE, but not particularly red-sensitive
TMAS foci
- Channel 1: F/26.392; f = 134.072m; 10 mas / pixel = 10 mas / 6.5 um = 1.5385 mas/um = 1.5385 "/mm or 0.65 mm/ " (assuming NEO camera)
- Nyquist at lambda = 492nm; FoV = 25.6" x 21.6"
- Channel 2: F/42.227; f = 214.515m; 16 mas / pixel = 16 mas / 6.5 um = 2.4615 mas / um = 2.4615 " / mm or 1.04 mm/ " (assuming NEO camera)
- Nyquist at lambda = 788nm, FoV = 41.0" x 34.6"
- Same focus would have 32 mas / pixel = 32 mas / 13 um; FoV = 32" x 32" assuming 888 iXon camera
- Alt focus 1: F/52.784; f = 268.144m; 10 mas / pixel = 10 mas / 13 um = 0.7693 mas/um = 0.7693 "/mm or 1.3 mm/ " (assuming 888 iXon camera)
- Nyquist at lambda = 492nm; FoV = 12.8" x 10.8"
- Alt focus 2a: F/84.454; f = 429.03m; 16 has / pixel = 16 mas / 13 um = 1.2308 mas / um = 1.2308 " / mm or 0.813 mm / " (assuming 888 iXon camera)
- Nyquist at lambda = 788nm, FoV = 20.5" x 17.3"
- Alt focus 2b: F/26.392; f = 134.072m; 10 mas / pixel = 10 mas / 6.5 um = 1.5385 mas/um = 1.5385 "/mm or 0.65 mm/ " (assuming NEO camera)
- Nyquist at lambda = 492nm; FoV = 25.6" x 21.6"
- Alt focus 2b is identical to Channel 1.
MGS Calibration Defocus Requirement
- We'd like to be able to move one of the cameras in and out of focus enough to generate > 200 pixels across the image. With the larger 13um pixels, this means a spot size that is > 2.6 mm in diameter. At the slower F/42 focus, this would be about +- 100 mm of travel. Newport makes a UTS 150, which could do +- 75 mm, which would give ~ 150 pixels across. I think this will be okay to calibrate our 64 actuators across the pupil (and at F/26 would be more than enough). So, we decide on the UTS 150.
AO modes
- S64 = 64 x 64 subaperture AO correction, limiting mag R ~ 7 provides 0.6um SR ~ 10%, 0.8um SR ~ 20%, FWHM < 0.2" at 35" off-axis
- S32 = 32 x 32 subaperture AO correction, limiting mag R ~ 10 provides visible FWHM < 0.2" on-axis, ~0.3" at 35" off-axis
- S8 = 8 x 8 subaperture AO correction, limiting mag R ~ 17 provides visible FWHM ~ 0.4" on- or off-axis
AO beamsplitters
- 50/50 beamsplitter
- 80/20 visible (trans/refl) + long pass beyond 970nm (TBC)
- 650 nm long pass
- 750 nm long pass (TBC)
- 970 nm long pass
TMAS observing modes
Mode Number |
AO config |
F/43 focus |
F/11 focus |
Science Case |
1 |
S64 |
Imaging filter |
Acquisition |
12 mas/pixel imaging for all visible wavelengths |
1 |
S64 |
Imaging filter |
Acquisition |
AO-assisted speckle (Lucky) imaging (Hildebrandt) |
1 |
S64 |
Imaging filter |
Acquisition |
Lowest R imaging of faintest targets |
2 |
S64 or S32 |
Imaging filter 1 |
Imaging filter 2 |
Dual-color photometry on different plate scales |
2 |
S64 or S32 |
Imaging filter 1 |
Imaging filter 2 |
Narrow field PSF reference for wider-field astrometry |
2 |
S64 or S32 |
Imaging filter 1 |
Imaging filter 2 |
Scattered light subtraction for extragalactic emission line science (Dekany) |
3 |
S64 or S32 |
Flexure and exp. meter |
Single-mode fiber |
10 cm/s precision radial velocity for exoplanet study (Johnson) |
3 |
> 650nm for WFS |
< 500nm for Andor |
feeding precision RV spectrograph (need to identify) |
10 cm/s precision radial velocity for exoplanet study (Johnson) |
4 |
S32 or S64 |
Flexure compensation |
Imaging filter 2 |
Deep (long-exposure) visible imagery / galaxy morphology / UDF |
4 |
S32 or S64 |
Flexure compensation |
Imaging filter 2 |
Red-channel coronagraphy (e.g. Serabyn (vortex coronagraphy)) |
5 |
S8 |
TBD |
GLAO w/ ~0.3" FWHM across moderate field |
Astrometry survey / identification of transients contexts |
5 |
S8 |
TBD |
across visible wavelength |
Astrometry survey / identification of transients contexts |
6 |
S8 |
Flexure & DAR |
Dual, scrambled multi-mode fiber |
5 m/s RV of close (<2") binary stars (Johnson) |
6 |
S8 |
compensation |
w/ one on 2-axis stage |
5 m/s RV of close (<2") binary stars (Johnson) |
This topic: Palomar/TMAS
> WebHome > ArchitectureDefinition
Topic revision: r7 - 2011-11-09 - RichardDekany