The Keck Cosmic Web Imager: a capable new integral field spectrograph for the W. M. Keck Observatory

Abstract

The Keck Cosmic Web Imager (KCWI) is a new facility instrument being developed for the W. M. Keck Observatory and funded for construction by the Telescope System Instrumentation Program (TSIP) of the National Science Foundation (NSF). KCWI is a bench-mounted spectrograph for the Keck II right Nasmyth focal station, providing integral field spectroscopy over a seeing-limited field up to 20"x33" in extent. Selectable Volume Phase Holographic (VPH) gratings provide high efficiency and spectral resolution in the range of 1000 to 20000. The dual-beam design of KCWI passed a Preliminary Design Review in summer 2011. The detailed design of the KCWI blue channel (350 to 700 nm) is now nearly complete, with the red channel (530 to 1050 nm) planned for a phased implementation contingent upon additional funding. KCWI builds on the experience of the Caltech team in implementing the Cosmic Web Imager (CWI), in operation since 2009 at Palomar Observatory. KCWI adds considerable flexibility to the CWI design, and will take full advantage of the excellent seeing and dark sky above Mauna Kea with a selectable nod-and-shuffle observing mode. In this paper, models of the expected KCWI sensitivity and background subtraction capability are presented, along with a detailed description of the instrument design. The KCWI team is lead by Caltech (project management, design and implementation) in partnership with the University of California at Santa Cruz (camera optical and mechanical design) and the W. M. Keck Observatory (program oversight and observatory interfaces).

QSO MUSEUM I: a sample of 61 extended Ly α-emission nebulae surroundingz∼ 3 quasars

“…Nevertheless, recently, the deployment of new advanced integral field spectrographs on 10-m class telescopes, i.e. the Multi-Unit Spectroscopic Explorer (MUSE; Bacon et al 2010) on the ESO/VLT and the Keck Cosmic Web Imager (KCWI; Morrissey et al 2012), opened up the possibility of routinely performing such an experiment by targeting very low levels of surface brightness (SB). Indeed, the latest observations are able to directly studying in emission at least the CGM of galaxies with reasonable observational times (∼tens of hours).…”

High-efficiency UV/optical/NIR detectors for large aperture telescopes and UV explorer missions: development of and field observations with delta-doped arrays

“…Palomar were completed with this detector behind the Cosmic Web Imager (CWI) 61,62 as part of an ongoing campaign to evaluate the detector's on sky performance and to obtain a science data to set the stage for future space missions. The first of these runs was in Nov. 2015, with follow up in spring and fall of 2016.…”

LZIFU: an emission-line fitting toolkit for integral field spectroscopy data

“…Future surveys using high-multiplex integral field unit (IFU) instrument such as HECTOR on the Anglo-Australian Telescope will observe on the order of 100,000 galaxies . Current and forthcoming wide-field IFU instruments are also delivering large quantity of high quality data, such as the Wide Field Spectrograph (WiFeS) on the Australian National University 2.3m telescope (Dopita et al 2007, the new Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (Bacon et al 2010), the SITELLE instrument on the Canada France Hawaii Telescope (Grandmont et al 2012), the Keck Cosmic Web Imager at the W. M. Keck Observatory (Martin et al 2010;Morrissey et al 2012).…”