Blue & Red Channel Spectrographs

A Brief Description:

The MMT Spectrograph is actually composed of two spectrographs sharing a common focal plane assembly and two filter wheels. The spectrographs are denoted Blue Channel and Red Channel for the wavelength ranges for which they are optimized. The instrument mounts to the standard MMT f/9 top box which houses the acquisition and guide cameras, the comparison lamp system and a wavefront sensor. Note: Remote observing is available for both instruments if you have previously observed with them in person at the MMT during good weather with the dome open for at least part of the night.

Blue Channel (Available): a low-to-intermediate resolution instrument optimized for spectroscopy in the range from 3200-8000 Å. A number of gratings are available giving resolution as high as 30 km/sec. Three gratings can be resident in the spectrograph at any one time, thereby facilitating rapid reconfiguration of the spectrograph. The current detector is a highly-optimized ITL/STA 2688×512 CCD. Instrument reference.

Red Channel (Unavailable*): a 3.75″ beam spectrograph optimized for the region 5000 Å to 1.0 μm but usable down to about 3700 Å. A highly-optimized ITL/STA 520×1032 fully depleted CCD is used as the detector. The spectrograph has several operating modes including high-throughput long-slit modes at a variety of spectral resolutions from 20 Å to about 2 Å and prism cross-dispersed modes yielding complete coverage from 4500 Å to 1.0 μm at moderate spectral resolution. As in the case of the Blue Channel, three gratings can reside in the spectrograph at any one time. Instrument reference. *There is a glow present in the Red Channel detector. Please see the Red Channel webpage.

The Fundamental Capabilities:

Please follow the Blue and Red Channel links below to see tables of the fundamental capabilities.

Further Information:

For hints and tips on how to operate the instrument please see the Cheat Sheets.