ESO, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany
TABLE OF CONTENTS
1.!Introduction ........................................................................................................................7!
1.1!Scope...........................................................................................................................8!
1.2!X-shooter in a nutshell .................................................................................................8!
1.3!Shortcuts to most relevant facts for proposal preparation ...........................................8!
1.4!List of Abbreviations & Acronyms ................................................................................9!
1.5!Reference Documents .................................................................................................9!
2.!Technical description of the instrument ...........................................................................10!
2.1!Overview of the opto-mechanical design...................................................................10!
2.2!Description of the instrument sub-systems................................................................11!
2.2.1!The Backbone.....................................................................................................11!
The Instrument Shutter and The calibration unit.........................................................11!
The Acquisition and Guiding slide. .............................................................................12!
The IFU.......................................................................................................................13!
The Acquisition and Guiding Camera .........................................................................13!
The dichroic box .........................................................................................................14!
The flexure compensation tip-tilt mirrors.....................................................................15!
The Focal Reducer and Atmospheric Dispersion Correctors .....................................15!
2.2.2!The UVB spectrograph .......................................................................................16!
Slit carriage .................................................................................................................16!
Optical layout ..............................................................................................................17!
Detector ......................................................................................................................17!
2.2.3!The VIS spectrograph .........................................................................................19!
Slit carriage .................................................................................................................19!
Optical layout ..............................................................................................................19!
Detector ......................................................................................................................19!
2.2.4!The NIR spectrograph ........................................................................................19!
Pre-slit optics and entrance window ...........................................................................19!
Slit wheel ....................................................................................................................20!
Optical layout ..............................................................................................................20!
Detector ......................................................................................................................21!
2.3!Spectral format, resolution and overall performances ...............................................24!
2.3.1!Spectral format ...................................................................................................24!
2.3.2!Spectral resolution and sampling........................................................................24!
2.3.3!Overall sensitivity................................................................................................24!
2.4!Instrument features and problems to be aware of .....................................................26!
2.4.1!UVB and VIS detectors sequential readout ........................................................26!
2.4.2!Remnance ..........................................................................................................26!
2.4.3!Instrument stability ..............................................................................................26!
Backbone flexures ......................................................................................................26!
Spectrograph flexures.................................................................................................26!
3.!Observing with X-shooter ................................................................................................27!
3.1!Observing modes and basic choices .........................................................................27!
3.2!Target acquisition ......................................................................................................27!
3.3!Spectroscopic observations.......................................................................................28!
3.3.1!Staring (SLIT and IFU)........................................................................................28!
3.3.2!Staring synchronized (SLIT and IFU) .................................................................28!
3.3.3!Nodding along the slit (SLIT only).......................................................................28!
3.3.4!Fixed offset to sky (SLIT and IFU) ......................................................................29!
3.3.5!Generic offset (SLIT and IFU).............................................................................29!
