VLT-MAN-ESO-14650-4942
P96
24.06.2015
9 of 161
ESO, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany
2.4.8.1 Backbone flexures.........................................................................................60
2.4.8.2 Spectrograph flexures ...................................................................................60
2.4.9 Radial velocity accuracy................................................................................60
2.4.10 NIR 11th order vignetting (K band) .................................................................61
2.4.11 VIS CCD pick-up noise..................................................................................62
2.4.12 NIR –IFU parasitic reflections........................................................................62
2.4.13 UVB/VIS ADCs problem................................................................................63
2.4.14 Drift of acquisition reference positions...........................................................63
2.4.15 TCCD features ..............................................................................................63
3. Observing with X-shooter .............................................................................................64
3.1 Observing modes and basic choices.....................................................................64
3.2 Target acquisition..................................................................................................65
3.2.1 Acquisition loop .............................................................................................65
3.2.2 Blind offset precisions ...................................................................................66
3.3 Examples of OBs preparations/acquisitions with p2pp3 ........................................67
3.3.1 Direct acquisition...........................................................................................67
3.3.2 Blind offset acquisition...................................................................................73
3.4 Spectroscopic observations ..................................................................................75
3.4.1 Overview and important remarks...................................................................75
3.4.1.1 Observing modes ..........................................................................................75
3.4.1.2 Effect of atmospheric dispersion....................................................................75
3.4.1.3 Exposure time in the NIR arm .......................................................................75
3.4.2 Staring (SLIT and IFU) ..................................................................................76
3.4.3 Staring synchronized (SLIT and IFU) ............................................................76
3.4.4 Nodding along the slit (SLIT only)..................................................................77
3.4.5 Fixed offset to sky (SLIT and IFU) .................................................................78
3.4.6 Generic offset (SLIT and IFU) .......................................................................78
3.4.7 and IFU) templates........................................................................................78
3.5 Observation strategy, summary, and tricks ...........................................................79
3.5.1 Instrument setup ...........................................................................................79
3.5.2 Observation strategy .....................................................................................80
3.5.3 Telluric standard stars and telluric lines correction (see also Sect.6.6.1) .......82
3.5.4 Observing bright objects, limiting magnitudes, and the diaphragm mode ......82
3.5.5 Readout times in the UVB and VIS arms: minimization of overheads............83
4. The XSHOOTER imaging mode ...................................................................................84
5. Instrument and telescope overheads ..........................................................................100
5.1.1 Summary of telescope and instrument overheads.......................................100
5.1.2 Execution time computation and how to minimize the overheads ................102
6. Calibrating and reducing X-shooter data.....................................................................104
6.1 X-shooter calibration plan ...................................................................................104
6.2 Wavelength and spatial scale calibration.............................................................107
6.3 Flat-field and Wavelength calibrations.................................................................108
6.4 Spectroscopic skyflats.........................................................................................109
6.5 Attached calibrations...........................................................................................110
6.6 Spectrophotometric calibration............................................................................110
6.6.1 Telluric absorption correction ......................................................................110
6.6.2 Absolute flux calibration ..............................................................................112
6.7 The X-shooter pipeline ........................................................................................113
6.8 Examples of observations with X-shooter............................................................114
6.9 Frequently Asked Questions ...............................................................................114
7. Reference material .....................................................................................................116
