Publications associées à Diagramme couleur-magnitude des galaxies

The Halos and Environments of Nearby Galaxies (HERON) survey IV. Complexity in the boxy galaxies NGC720 and NGC2768

The shapes of galaxies, their outer regions in particular, are important guideposts to their formation and evolution. In this work, we report on the discovery of strongly box-shaped morphologies of the otherwise well-studied elliptical and lenticular galax ...

Edp Sciences S A2024

Strong gravitational lensing's 'external shear' is not shear

David Richard Harvey, Mathilde Jauzac, Richard Massey

The distribution of mass in galaxy-scale strong gravitational lenses is often modelled as an elliptical power-law plus 'external shear', which notionally accounts for neighbouring galaxies and cosmic shear along our line of sight. A small amount of externa ...

Oxford Univ Press2024

CEERS Key Paper. VII. JWST/MIRI Reveals a Faint Population of Galaxies at Cosmic Noon Unseen by Spitzer

Michaela Hirschmann

The Cosmic Evolution Early Release Science program observed the Extended Groth Strip (EGS) with the Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope (JWST) in 2022. In this paper, we discuss the four MIRI pointings that observed with longer ...

Iop Publishing Ltd2023

An Atlas of Color-selected Quiescent Galaxies at z > 3 in Public JWST Fields

Michaela Hirschmann, Minju Lee

We present the results of a systematic search for candidate quiescent galaxies in the distant universe in 11 JWST fields with publicly available observations collected during the first 3 months of operations and covering an effective sky area of similar to ...

IOP Publishing Ltd2023

A model for the infrared-radio correlation of main sequence galaxies at gigahertz frequencies and its variation with redshift and stellar mass

Jennifer Waltraud Schober, Mark Thomas Sargent

Context. The infrared-radio correlation (IRRC) of star-forming galaxies can be used to estimate their star formation rate (SFR) based on the radio continuum luminosity at MHz-GHz frequencies. For its practical application in future deep radio surveys, it i ...

Edp Sciences S A2023

From starburst to quenching: merger-driven evolution of the star formation regimes in a shell galaxy

Jonathan Erik Peter Petersson

Shell galaxies make a class of tidally distorted galaxies, characterized by wide concentric arc(s), extending out to large galactocentric distances with sharp outer edges. Recent observations of young massive star clusters in the prominent outer shell of N ...

OXFORD UNIV PRESS2022

SEEDisCS: I. Molecular gas in galaxy clusters and their large-scale structure: The case of CL1411.1-1148 at z similar to 0.5

Pascale Jablonka, Gianluca Castignani, Damien Louis Alexandre Spérone-Longin

We investigate how the galaxy reservoirs of molecular gas fuelling star formation are transformed while the host galaxies infall onto galaxy cluster cores. As part of the Spatially Extended ESO Distant Cluster Survey (SEEDisCS), we present CO(3-2) observat ...

EDP SCIENCES S A2021

Virgo filaments I. Processing of gas in cosmological filaments around the Virgo cluster

Pascale Jablonka, Gianluca Castignani

It is now well established that galaxies have different morphologies, gas contents, and star formation rates (SFR) in dense environments like galaxy clusters. The impact of environmental density extends to several virial radii, and galaxies appear to be pr ...

EDP SCIENCES S A2021

Cold gas in the cosmic web around galaxy clusters

Damien Louis Alexandre Spérone-Longin

Galaxies live in very different types of environment. Those different environments are relics from the evolution of the Universe since the Big Bang. This network of structures observed via large scale surveys is called Cosmic Web. Within this web, galaxies ...

EPFL2021

Unveiling the Intrinsic Alignment of Galaxies with Self-calibration and DECaLS DR3 Data

Jean-Paul Richard Kneib, Huanyuan Shan

Galaxy intrinsic alignment (IA) is a source of both systematic contamination of cosmic shear measurement and its cosmological applications and valuable information on the large-scale structure of the universe and galaxy formation. The self-calibration (SC) ...

IOP PUBLISHING LTD2020

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: GLAM-QPM mock galaxy catalogues for the emission line galaxy sample

Cheng Zhao, Johan Comparat, Anand Stéphane Raichoor

We present 2000 mock galaxy catalogues for the analysis of baryon acoustic oscillations (BAOs) in the Emission Line Galaxy (ELG) sample of the extended Baryon Oscillation Spectroscopic Survey Data Release 16 (eBOSS DR16). Each mock catalogue has a number d ...

OXFORD UNIV PRESS2020

Molecular gas in distant brightest cluster galaxies

Gianluca Castignani

The mechanisms governing the stellar mass assembly and star formation history of brightest cluster galaxies (BCGs) are still being debated. By means of new and archival molecular gas observations we investigate the role of dense megaparsec-scale environmen ...

2020

The Pristine Dwarf-Galaxy survey - II. In-depth observational study of the faint Milky Way satellite Sagittarius II

Pascale Jablonka, Nicolas Lawrence Etienne Longeard

We present an extensive study of the Sagittarius II (Sgr II) stellar system using MegaCam g and i photometry, narrow-band, metallicity-sensitive calcium H&K doublet photometry and Keck II/DEIMOS multiobject spectroscopy. We derive and refine the Sgr II str ...

OXFORD UNIV PRESS2020

The time delay between star formation quenching and morphological transformation of galaxies in clusters: a phase-space view of EDisCS

Pascale Jablonka

We explore the possible effect of cluster environments on the structure and star formation histories of galaxies by analysing the projected phase-space (PPS) of intermediate-redshift clusters (0.4

OXFORD UNIV PRESS2019

The impact of cored density profiles on the observable quantities of dwarf spheroidal galaxies

Yves Revaz, David Richard Harvey, Loïc Hausammann

We modify the chemo-dynamical code GEAR to simulate the impact of self-interacting dark matter (SIDM) on the observable quantities of 19 low-mass dwarf galaxies with a variety star-forming properties. We employ a relatively high, velocity independent cross ...

OXFORD UNIV PRESS2018

ARE ULTRA-FAINT GALAXIES AT z=6-8 RESPONSIBLE FOR COSMIC REIONIZATION? COMBINED CONSTRAINTS FROM THE HUBBLE FRONTIER FIELDS CLUSTERS AND PARALLELS

Jean-Paul Richard Kneib, Hakim Atek, Benjamin Yvan Alexandre Clement, Mathilde Jauzac, Johan Richard

We use deep Hubble Space Telescope imaging of the Frontier Fields to accurately measure the galaxy rest-frame ultraviolet luminosity function (UV LF) in the redshift range z similar to 6-8. We combine observations in three lensing clusters, A2744, MACS 041 ...

Iop Publishing Ltd2015

New constraints on the faint end of the UV luminosity function at z∼ 7-8 using the gravitational lensing of the hubble frontier fields cluster A2744

Jean-Paul Richard Kneib, Hakim Atek, Benjamin Yvan Alexandre Clement, Mathilde Jauzac, Johan Richard

Exploiting the power of gravitational lensing, the Hubble Frontier Fields (HFF) program aims at observing six massive galaxy clusters to explore the distant universe far beyond the limits of blank field surveys. Using the complete Hubble Space Telescope ob ...

American Astronomical Society2015

HST/WFC3 Near-Infrared spectroscopy of quenched galaxies at z~1.5 from the WISP Survey: Stellar population properties

Hakim Atek

We combine Hubble Space Telescope (HST) G102 and G141 near-IR (NIR) grism spectroscopy with HST/WFC3UVIS, HST/WFC3-IR, and Spitzer/IRAC [3.6 mu m] photometry to assemble a sample ofmassive (log(M-star/M-circle dot) similar to 11.0) and quenched (specific s ...

American Astronomical Society2013

Stochastic bias of colour-selected BAO tracers by joint clustering-weak lensing analysis

Jean-Paul Richard Kneib, Johan Comparat, Huanyuan Shan, David Schlegel

The baryon acoustic oscillation (BAO) feature in the two-point correlation function of galaxies supplies a standard ruler to probe the expansion history of the Universe. We study here several galaxy selection schemes, aiming at building an emission-line ga ...

Oxford Univ Press2013

The Low-Mass Initial Mass Function In The 30 Doradus Starburst Cluster

Marilyne Andersen, Georges Meylan

We present deep Hubble Space Telescope NICMOS 2 F160W band observations of the central 56 '' x 57 '' (14 pc x 14.25 pc) region around R136 in the starburst cluster 30Dor (NGC 2070) located in the Large Magellanic Cloud. Our aim is to derive the stellar ini ...

2009