Cosmic Web Imager (CWI)

The Cosmic Web Imager (CWI) is a P200 instrument & 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).

CWI Instrument Specifications


Parameter

Value

Status

Semi-Private (contact cmartin@srl.caltech.edu)

Field of View

60 x 40 arcseconds

Spatial Resolution

2.5 x 1 arcseconds

Field Orientation

Adjustable 0 to 90 deg

Accessible Spectral Range 1

405 – 440 nm

450 – 540 nm

630 – 760 nm

Spectral Bandpass

~ 15 nm Nod & Shuffle

~ 45 nm unmasked

Spectral Resolution (R = lambda / D lambda)

5000 (D lambda ~ 0.1 nm)

Estimated Efficiency

10% 2

CCD Format

4096 x 4096

Pixel Size

15 um

Pixel Binning

1x1, 2x2

Read Noise

< 2.8 e-

Readout Time (2x2)

2, 1, or 0.5 min (through 1, 2, or 4 amplifers)

Scripted Nod & Shuffle

Yes


1 The 405 – 440 nm and 630 – 740 nm gratings are on order as of this writing (Aug 2011).

2 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.
CWI Specification -- version 18 August 2011
Last Modified 18 August 2011 -- AFB