Change page style: 

Detector Information

T-ReCS contains the same detector as Michelle . Some basic characteristics of the detectors are shown in the table below:


Basic characteristics of T-ReCS's imaging mode

T-ReCS is capable of imaging in the 8–26 micron range as follows:

  • Broad-band (N, Q) and Narrow-band Filter Imaging
  • Pixel size = 0.09" (fixed)
  • Field of view = 28.8"×21.6"
  • Number of filters: currently 20, capacity for 24
  • Occulting bar available for imaging (2" wide)

The principal T-ReCS imaging modes, plus the typical settings of five instrument components in each mode, are listed in the following table.

Sensitivity and Overheads

This section contains information on the sensitivity and performance of T-ReCS in its various observing modes. Go directly to:

Blocking Filters

The following table gives wavelength ranges of the order-sorting filters in NIRI that are used with the grisms. The Gemini identification number for each filter is recorded in data file headers.


The available slits are shown in the following table. The slit widths are given in pixels and arcsec projected on the sky. The spectral resolution is lower in a wider slit (see the grism table), even for point sources since under most atmospheric conditions the seeing wings of pointlike objects fill the wider slits. Note that for each f/6 slit width, 2 slits are available, one of which is offset from the optical axis and causes the spectrum to be shifted to shorter wavelengths on the array. Note also that the f/32 10 pixel wide slit and the f/6 2 pixel wide slit are the same slit.


Basic characteristics of T-ReCS's spectroscopy modes

T-ReCS is capable of spectroscopy with R~100 - 1000 in the 8–26 micron range as follows:


Basic characteristics of T-ReCS's imaging mode

Taken from the current T-ReCS Intro page

Exposure times

The following five tables provide various exposure time limits. Constraints are due to a number of factors, more than one of which may need to be considered for a given NIRI configuration:

  • Minimum possible exposure time due to array electronics (Table 1)

  • Efficiency - ensuring that a much larger percentage of the time is spent exposing the array than reading it out (Table 2)

  • Time required for noise from fluctuations in the sky+telescope background to equal read noise (Table 3)

  • Maximum possible exposure time before array is saturated by background (Table 4)
  • Observation Preparation

    This section mainly describes how to prepare and check NIRI observations. Setting up observing sequences at Phase II is not intuitive until one is quite experienced (and maybe even not then). Thus, the key to successful observation preparation is starting from the NIRI OT Library.


    Low-moderate resolution spectroscopy can be obtained either at f/6 through each of the 1-5μm windows or at f/32 (the latter usually with adaptive optics) at JHK only. A variety of slit widths are available. The properties of the slits, grisms, and blocking filters are decribed in the section. The f/6 and f/32 pixel scales in spectroscopy mode are the same as those in imaging mode.