JWST spectra of six z=5-9 galaxies show low-ionization covering fractions of 0.2-0.9 and diverse kinematics including blueshifted outflows, indicating heterogeneous multiphase ISM.
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The Keck Cosmic Web Imager Integral Field Spectrograph
14 Pith papers cite this work, alongside 224 external citations. Polarity classification is still indexing.
14
Pith papers citing it
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external citations · Pith
abstract
We report on the design and performance of the Keck Cosmic Web Imager (KCWI), a general purpose optical integral field spectrograph that has been installed at the Nasmyth port of the 10 m Keck II telescope on Mauna Kea, HI. The novel design provides blue-optimized seeing-limited imaging from 350-560 nm with configurable spectral resolution from 1000 - 20000 in a field of view up to 20"x33". Selectable volume phase holographic (VPH) gratings and high performance dielectric, multilayer silver and enhanced aluminum coatings provide end-to-end peak efficiency in excess of 45% while accommodating the future addition of a red channel that will extend wavelength coverage to 1 micron. KCWI takes full advantage of the excellent seeing and dark sky above Mauna Kea with an available nod-and-shuffle observing mode. The instrument is optimized for observations of faint, diffuse objects such as the intergalactic medium or cosmic web. In this paper, a detailed description of the instrument design is provided with measured performance results from the laboratory test program and ten nights of on-sky commissioning during the spring of 2017. The KCWI team is lead by Caltech and JPL (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 (observatory interfaces).
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representative citing papers
An extended Lyα halo is detected around the z=6.64 BAL quasar J0910-0414, extending to 11 pkpc with rotation-like kinematics, lower velocity dispersion than the host core, and contributing 55% of the total Lyα flux due to central absorption.
New JWST and Keck data on off-nuclear TDE 2025abcr show shifting emission-line velocities from a changing reprocessing layer and an IR power-law slope of -2.13 that is consistent with either reprocessing gas or a young stellar cluster of mass ~10^7.6 solar masses.
Spectroscopic data indicate that the ionized gas in ORC4's central galaxy is shock-ionized by a wind associated with the radio ring's formation.
Non-detections of expected third flares in TDE 2022dbl and TDE 2020vdq support rpTDE interpretation over independent events, with modeling favoring bound main-sequence star orbits and deep initial encounters.
Spatially resolved observations of z~0.1 galaxies show Mg II absorption outflow velocities are systematically higher than Hα emission velocities by ~0.4 dex while maintaining similar correlations with star formation rate and surface density.
Lya nebulae around unobscured quasars are more extended, asymmetric, and show steeper velocity dispersion declines than those around obscured quasars, supporting an evolutionary AGN model at cosmic noon.
Radial velocity data reveal a 310-day orbital period in NaSt1 with opposing phases in two groups of emission lines, supporting its nature as a post-mass-transfer massive binary system.
Non-Gaussian LSF shapes bias kinematic extraction from spectra; matching the LSF of templates to the target reduces dispersion bias below 1%.
Bayesian IMF-aware inference on NGC 1569 clusters yields correlations between cluster mass-function truncation mass, galactocentric distance, metallicity, and gas ionization state.
SN 2025coe's double-peaked light curve and nebular spectra are consistent with either an asymmetric core-collapse explosion of a low-mass He-core progenitor or a thermonuclear hybrid white dwarf merger.
New spectroscopy rules out PG 0931+691 as ionizer of WPS 46 and associates the source with an IVC ionized by shocks.
A bias-controlled quasar sample of ~2000 objects demonstrates that the X-ray-to-UV luminosity relation remains constant from redshift 0.7 to 5.
Spatially resolved kinematics show SLACS lens galaxies have nearly isothermal total mass profiles (mean γ=2.04) with average mass-sheet parameter λ_int=1.01, consistent with no measurable bias from power-law assumptions in cosmography.
citing papers explorer
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JWST absorption line spectroscopy with SPURS: ISM covering fractions and kinematics in individual galaxies at $z=5-9$
JWST spectra of six z=5-9 galaxies show low-ionization covering fractions of 0.2-0.9 and diverse kinematics including blueshifted outflows, indicating heterogeneous multiphase ISM.
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Detection of an Extended Ly$\alpha$ Halo around a $\textit{z}=6.64$ Broad Absorption Line Quasar with the Keck Cosmic Web Imager
An extended Lyα halo is detected around the z=6.64 BAL quasar J0910-0414, extending to 11 pkpc with rotation-like kinematics, lower velocity dispersion than the host core, and contributing 55% of the total Lyα flux due to central absorption.
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JWST and Keck observations of the off-nuclear tidal disruption event TDE 2025abcr: An evolving reprocessing layer
New JWST and Keck data on off-nuclear TDE 2025abcr show shifting emission-line velocities from a changing reprocessing layer and an IR power-law slope of -2.13 that is consistent with either reprocessing gas or a young stellar cluster of mass ~10^7.6 solar masses.
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A Shocked Wind Interpretation of an Odd Radio Circle
Spectroscopic data indicate that the ionized gas in ORC4's central galaxy is shock-ionized by a wind associated with the radio ring's formation.
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A Disappearing Act: Constraints From "Missing" Flares of Repeating Partial TDE Candidates
Non-detections of expected third flares in TDE 2022dbl and TDE 2020vdq support rpTDE interpretation over independent events, with modeling favoring bound main-sequence star orbits and deep initial encounters.
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Differences between emission and absorption tracers of spatially resolved outflows in clumpy z ~ 0.1 star-forming galaxies
Spatially resolved observations of z~0.1 galaxies show Mg II absorption outflow velocities are systematically higher than Hα emission velocities by ~0.4 dex while maintaining similar correlations with star formation rate and surface density.
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Constraining the nature of active galactic nuclei through circumgalactic Lya emission at z=2-3
Lya nebulae around unobscured quasars are more extended, asymmetric, and show steeper velocity dispersion declines than those around obscured quasars, supporting an evolutionary AGN model at cosmic noon.
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Radial Velocity Evidence for a Post-Mass-Transfer Massive Binary System: NaSt1
Radial velocity data reveal a 310-day orbital period in NaSt1 with opposing phases in two groups of emission lines, supporting its nature as a post-mass-transfer massive binary system.
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The Impact of Non-Gaussian Line Spread Functions on Stellar Kinematic Recovery: Consequences for Dynamical Models
Non-Gaussian LSF shapes bias kinematic extraction from spectra; matching the LSF of templates to the target reduces dispersion bias below 1%.
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Getting to know the Stellar Clusters in NGC 1569: Bayesian inference of stellar cluster properties in a dwarf starburst galaxy
Bayesian IMF-aware inference on NGC 1569 clusters yields correlations between cluster mass-function truncation mass, galactocentric distance, metallicity, and gas ionization state.
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The Double-Peaked Calcium-Strong SN 2025coe: Progenitor Constraints from Early Interaction and Ejecta Asymmetries
SN 2025coe's double-peaked light curve and nebular spectra are consistent with either an asymmetric core-collapse explosion of a low-mass He-core progenitor or a thermonuclear hybrid white dwarf merger.
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The origin of WHAM Point Source~46
New spectroscopy rules out PG 0931+691 as ionizer of WPS 46 and associates the source with an IVC ionized by shocks.
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The X-ray-to-UV relation does not evolve in homogeneous quasar samples
A bias-controlled quasar sample of ~2000 objects demonstrates that the X-ray-to-UV luminosity relation remains constant from redshift 0.7 to 5.
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Spatially Resolved Kinematics of SLACS Lens Galaxies. II: Breaking Degeneracies with Lensing and Dynamical Models
Spatially resolved kinematics show SLACS lens galaxies have nearly isothermal total mass profiles (mean γ=2.04) with average mass-sheet parameter λ_int=1.01, consistent with no measurable bias from power-law assumptions in cosmography.