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The KLEVER Survey: spatially resolved metallicity maps and gradients in a sample of 1.2 < z < 2.5 lensed galaxies

Curti, Mirko; Maiolino, Roberto; Cirasuolo, Michele; Mannucci, Filippo; Williams, Rebecca J; Auger, Matt; Mercurio, Amata; Hayden-Pawson, Connor; Cresci, Giovanni; Marconi, Alessandro; Belfiore, Francesco; Cappellari, Michele; Cicone, Claudia; Cullen, Fergus; Meneghetti, Massimo; Ota, Kazuaki; Peng, Yingjie; Pettini, Max; Swinbank, Mark; Troncoso, Paulina

The KLEVER Survey: spatially resolved metallicity maps and gradients in a sample of 1.2 < z < 2.5 lensed galaxies Thumbnail


Mirko Curti

Roberto Maiolino

Michele Cirasuolo

Filippo Mannucci

Rebecca J Williams

Matt Auger

Amata Mercurio

Connor Hayden-Pawson

Giovanni Cresci

Alessandro Marconi

Francesco Belfiore

Michele Cappellari

Claudia Cicone

Fergus Cullen

Massimo Meneghetti

Kazuaki Ota

Yingjie Peng

Max Pettini

Paulina Troncoso


We present near-infrared observations of 42 gravitationally lensed galaxies obtained in the framework of the KMOS Lensed Emission Lines and VElocity Review (KLEVER) Survey, a programme aimed at investigating the spatially resolved properties of the ionized gas in 1.2 < z < 2.5 galaxies by means of a full coverage of the YJ, H, and K near-infrared bands. Detailed metallicity maps and gradients are derived for a subsample of 28 galaxies from reconstructed source-plane emission-line maps, exploiting the variety of different emission-line diagnostics provided by the broad wavelength coverage of the survey. About 85per cent of these galaxies are characterized by metallicity gradients shallower than 0.05 dexkpc−1 and 89 per cent are consistent with a flat slope within 3σ (⁠67 per cent within 1σ), suggesting a mild evolution with cosmic time. In the context of cosmological simulations and chemical evolution models, the presence of efficient feedback mechanisms and/or extended star formation profiles on top of the classical ‘inside-out’ scenario of mass assembly is generally required to reproduce the observed flatness of the metallicity gradients beyond z ∼ 1. Three galaxies with significantly (>3σ) ‘inverted’ gradients are also found, showing an anticorrelation between metallicity and star formation rate density on local scales, possibly suggesting recent episodes of pristine gas accretion or strong radial flows in place. Nevertheless, the individual metallicity maps are characterized by a variety of different morphologies, with flat radial gradients sometimes hiding non-axisymmetric variations on kpc scales, which are washed out by azimuthal averages, especially in interacting systems or in those undergoing local episodes of recent star formation.

Journal Article Type Article
Acceptance Date Nov 25, 2019
Online Publication Date Dec 19, 2019
Publication Date Feb 28, 2020
Deposit Date Feb 26, 2020
Publicly Available Date Feb 26, 2020
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 492
Issue 1
Pages 821-842
Public URL


Published Journal Article (5.4 Mb)

Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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