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GMOS Performance and Use

Status and availability:	The main observing modes (imaging; long-slit, MOS and IFU spectroscopy) for both GMOS North and South have been commissioned, system verification data have been obtained and these modes are available for use. Nod-and-shuffle is available for long-slit and MOS spectroscopy on both GMOSs. In addition, nod-and-shuffle is available for IFU spectroscopy on GMOS South only. Commissioning of the ADC has not yet started. For GMOS North and South availability in the next semester please see the most recent Call for Proposals.
Modes of operation:	GMOS has six instrument modes: Imaging Long-slit spectroscopy Multi-object spectroscopy Nod-and-Shuffle (long-slit and MOS for both GMOSs; IFU for GMOS South only) Integral field spectroscopy Polarimetry (not yet available) Details of these capabilities may be found in the GMOS components section. A more detailed summary of the modes and example data may be found in the System Verification section.
GMOS components:	See the GMOS components page (also linked from the GMOS contents menu) for details of filters, gratings, slits, IFU, detectors and other components, including description of the Nod-and-Shuffle mode.
Sensitivity:	The Integration Time Calculator can be used to determine limiting magnitudes, exposure times, S/N ratios, background levels, etc. for a wide range of source properties, observing conditions, filters, and GMOS configurations. The ITC was used to generate tables of sensitivity estimates for both imaging and spectroscopy modes. At this time these are estimates only. The R831 grating is not included in these example sensitivity estimates but is available for science use and is included in the ITC. The estimated image quality delivered to the instrument is given as part of the observing condition constraints.
Observing strategies:	See the Observing Strategies page for guidance and special considerations for each observing mode. When you're done, don't forget to check the Checklist.
Phase II Preparations:	See the Phase II Special Instructions. Example OT files for GMOS can be retrieved from the OT Library. For help getting started, please see the OT Tutorial page.
Observing overheads:	See GMOS Overheads for information on estimating acquisition and observing overheads. Note that only overheads actually used will be charged to the program. For Nod-and-Shuffle additional overheads apply. These are described on the Nod-and-Shuffle page.
Target acquisition:	For imaging and long-slit spectroscopy, see the generic target acquisition scenarios. For multi-object spectroscopy and integral field spectroscopy, more details are provided in the Observing Strategies page.
Calibration:	Flat-fielding and wavelength calibration of GMOS are to be carried out using the facility calibration unit. GCAL flat and arc exposure times are given in this table. Baseline calibrations will be obtained for all observations, both queue and classical. Information about photometric and spectroscopic standard stars are available.
Data processing and software:	The GMOS package of IRAF scripts has been released. A description of the data format and data examples is available. Various other notes on the data reduction are also available.

Last update: December 10, 2005; Kathy Roth
Previous version: August 30, 2005; Inger Jørgensen