Cosmic Web Imager (CWI) Technical Specifications

View the original specsheet.

The Cosmic Web Imager (CWI) is a P200 instrument and prototype developed by Chris Martin and colleagues at Caltech. CWI is available for science observing in a semi-private mode (potential users must contact/work with the CWI team).

Parameter Value
Status Semi-private (contact cmartin@srl.caltech.edu)
Field of view 60″ × 40″
Spatial resolution 2.5 × 1″
Field orientation Adjustable 0° to 90°
Accessible spectral range [a] 405 – 440 nm
450 – 540 nm
630 – 760 nm
Spectral bandpass ~ 15 nm Nod & Shuffle
~ 45 nm unmasked
Spectral resolution (R = λ/Δλ) 5000 (Δλ ~ 0.1 nm)
Estimated efficiency 10% [b]
CCD format 4096 × 4096
Pixel size 15 µm
Pixel binning 1 × 1, 2 × 2
Read noise < 2.8 e
Readout time (2x2) 2, 1, or 0.5 min (through 1, 2, or 4 amplifers)
Scripted Nod & Shuffle Yes
[a] The 405 – 440 nm and 630 – 740 nm gratings are on order as of this writing (Aug 2011).

[b] Estimated efficiency: ~10−18 ergs/cm2/s/arcsec2 after 3 hours on target and 3 hours on background.

An expanded CWI observer's writeup has been provided by the CWI team, and a CWI web-page is also available.

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CWI Specs / v 2.0
Last updated: 18 June 2015 ACM