Baseline Calibrations
Standard wavelength calibration and flat fielding for MODS1 and MODS2 obtained with each instruments own internal calibration unit. Baseline calibrations include biases, comparison lamp spectra, slitless and thru-slit continuum lamp flats, internal imaging flats, and spectrophotometric standards. Calibration scripts sets the PARTNER and PROPID as CALIBRATION, and sets the PI_NAME as ALL.
Flat fields appear to be very stable for a run, and the slitless pixel flats and slit flats do not have to be taken daily; once per run should suffice.
Biases, on the other hand, may vary, and for the imaging and prism readout regions of interest which do not have an overscan: i.e. 3K x 3K, 4K x 3K, 1K x 1K; it is recommended to take biases on the night that the data are taken.
Calibration Observations are included as part of the MODS OT Library. Calibration scripts generated from v10.24 of the library are in /lbt/lbto/mods/modsCalibs_OT/. Note that the calibration units for MODS1 and MODS2 differ slightly so the calibration times have been tailored for each instrument within the templates and are not identical for MODS1 and MODS2. Scripts for spectrophotometric standards are in the OT library and also in /lbt/lbto/mods/modsSpecPhot.
MODS Calibration Summary
Observing Mode |
Standard Instrument |
Biases |
Arcs |
Flat Fields |
Twilight Sky Flats |
Spectro-photometric Standards |
|||
|---|---|---|---|---|---|---|---|---|---|
| Spectral Slit Flats | Pixel to Pixel Slitless Flats | Imaging Flats | |||||||
Grating Long-slit Spectroscopy |
Binning: 1x1ROI: 8Kx3K |
Dual | About Biases | Arcs taken with: LS560x0.6 standard About Arcs |
To be taken with each long-slit used | About Pixel to Pixel Slitless Flats | N/A | About Slitless Twilight Flats (not recommended) |
Spec Phot Standards |
| Red | |||||||||
| Blue | |||||||||
| Grating
Multi-Slit |
Binning: 1×1
ROI: 8Kx3K |
Dual | About Biases | Arcs and Flats template to be adjusted for mask About MOS Arcs About MOS Flats |
About Pixel to Pixel Slitless Flats | N/A | About MOS Slitless Twilight Flats (not recommended) |
Spec Phot Standards | |
| Red | |||||||||
| Blue | |||||||||
| Prism
Long-Slit |
Binning: 1×1
ROI: 4Kx3K |
Dual | About Biases | Arcs taken with: LS560x0.3 standard About Arcs |
About Long Slit Flats | Prism slitless flats saturate and are not to be used | N/A | About Slitless Twilight Flats (not recommended) |
Spec Phot Standards |
| Red | |||||||||
| Blue | |||||||||
| Prism
Multi-Slit |
ROI: 4Kx3K
Binning: 1×1 |
Dual | About Biases | Arcs and Flats template to be adjusted for mask About Arcs About Flats |
Prism slitless flats saturate and are not to be used | N/A | About MOS Slitless Twilight Flats (not recommended) |
Spec Phot Standards | |
| Red | |||||||||
| Blue | |||||||||
| Imaging | ROI: 3Kx3K
Binning: 1×1 |
Dual | About Biases | N/A | N/A | N/A | About Imaging Pixel to Pixel Flats | Imaging Twilight Flats (recommended) |
N/A |
| Red | |||||||||
| Blue | |||||||||
