The two Gemini Multi-Object Spectrographs (GMOS), one on each telescope, provide 0.36-0.94 µm long-slit and multi-slit spectroscopy and imaging over a 5.5 arcminute field of view. Each GMOS is also equipped with an Integral Field Unit (IFU) making it possible to obtain spectra from a 35 square arcsecond area with a sampling of 0.2 arcseconds. The Nod-and-Shuffle mode, which enables superior sky subtraction, is available with both GMOS-N and GMOS-S in most spectroscopic modes.

The GMOS were built by a collaboration of the Astronomy Technology Centre at the ROE, the University of Durham in the UK and the Herzberg Institute of Astrophysics in Canada. GMOS-N was delivered in July 2001 with GMOS-S following in December 2002.

The Instrument Scientists for GMOS are German Gimeno (GMOS-S) and Kathy Roth (GMOS-N).

Announcements

New Red-Sensitive CCDs manufactured by Hamamatsu Photonics have been purchased for GMOS-N, more information regarding these CCDs is available on the GMOS-N Array (Hamamatsu) webpages. Installation of these devices has met with some difficulty and the project is delayed. As an interim solution Gemini has also purchased deep depletion devices from e2v, more information will be available regarding these CCDs on the GMOS-N Array (e2v DD) webpages. The e2v DD devices will be installed first while the issues with the eventual Hamamatsu upgrade are resolved. See the Status and Availability webpage for more details.

In order to allow observers to take advantage of the wavelength regime opened up by the new detectors on GMOS-N, we will be installing two new filters (Z and Y) for imaging and band limited spectroscopy in the far red. These new filters will be installed when the new Hamamatsu CCDs are commissioned, contingent on delivery schedules. See the GMOS filters webpage for more details.

See the Status and Availability page for current instrument configurations.

GMOS Science Highlights

How to Use These Pages

The GMOS pages are organized as follows:

• Status and Availability: Modes available in the current and upcoming semesters; current grating and slit configurations.
• Nod-and-Shuffle: All you ever wanted to know about this remarkable GMOS capability - including when and how to use it.
• Imaging: GMOS is not just a MOS, or an S; it is a camera too; info on camera properties, filters and detectors.
• Spectroscopy Overview: Introduction and properties of gratings, blocking filters, and detectors.
• Long-slit Spectroscopy
• Multi-object Spectroscopy (including mask-making)
• Integral Field Spectroscopy
• Sensitivity and Overheads: Sensitivity tables, integration time calculator, and details of observing overheads.
• Guiding Options: The GMOS OIWFS and how to use it; when to use the peripheral wavefront sensors with GMOS.
• Calibration: Info on GCAL, flats and arcs, standard stars, and baseline calibrations.
• Observation Preparation: How to configure GMOS in the Observing Tool; observing strategies and checklists.
• Data Format and Reduction: Examples of GMOS data and links to data reduction resources.
• Documents: GMOS optical layout; design documents and references.

GMOS-S gets some TLC. Click to view larger image.