Publications de Hakim Atek | EPFL Graph Search

Revealing galaxy candidates out to z similar to 16 with JWST observations of the lensing cluster SMACS0723

Johan Richard, Jean-Paul Richard Kneib, Hakim Atek

One of the main goals of the JWST is to study the first galaxies in the Universe. We present a systematic photometric analysis of very distant galaxies in the first JWST deep field towards the massive lensing cluster SMACS0723. As a result, we report the d ...

OXFORD UNIV PRESS2023

Euclid preparation XXI. Intermediate-redshift contaminants in the search for z > 6 galaxies within the Euclid Deep Survey

Georges Meylan, Frédéric Courbin, Hakim Atek, Richard Massey, Maurizio Martinelli, Jean-Luc Starck, Gianluca Castignani, Marcello Farina, Austin Chandler Peel, Yi Wang

Context. The Euclid mission is expected to discover thousands of z > 6 galaxies in three deep fields, which together will cover a similar to 50 deg(2) area. However, the limited number of Euclid bands (four) and the low availability of ancillary data could ...

EDP SCIENCES S A2022

The BUFFALO HST Survey

Johan Richard, Céline Tchernin, Matthieu Schaller, Pascale Jablonka, Jean-Paul Richard Kneib, Huanyuan Shan, Hakim Atek, Richard Massey, David Richard Harvey, Mathilde Jauzac, Benjamin Yvan Alexandre Clement, Anja Von der Linden

The Beyond Ultra-deep Frontier Fields and Legacy Observations (BUFFALO) is a 101 orbit + 101 parallel Cycle 25 Hubble Space Telescope (HST) Treasury program taking data from 2018 to 2020. BUFFALO will expand existing coverage of the Hubble Frontier Fields ...

IOP PUBLISHING LTD2020

The extreme faint end of the UV luminosity function at z similar to 6 through gravitational telescopes: a comprehensive assessment of strong lensing uncertainties

Johan Richard, Jean-Paul Richard Kneib, Hakim Atek

2018

Mapping substructure in the HST Frontier Fields cluster lenses and in cosmological simulations

Johan Richard, Jean-Paul Richard Kneib, Hakim Atek, Mathilde Jauzac, Cristina Popa

We map the lensing-inferred substructure in the first three clusters observed by the Hubble Space Telescope Frontier Fields (HSTFF) Initiative: Abell 2744 (z = 0.308), MACSJ 0416, (z = 0.396) and MACSJ 1149 (z = 0.543). Statistically resolving dark matter ...

Oxford Univ Press2017

A High Space Density of Luminous Ly alpha Emitters at z similar to 6.5

Hakim Atek, Patrick Mccarthy

We present the results of a systematic search for Ly alpha emitters (LAEs) at 6 less than or similar to z less than or similar to 7.6 using the HST WFC3 Infrared Spectroscopic Parallel (WISP) Survey. Our total volume over this redshift range is similar to ...

Iop Publishing Ltd2017

Strong-lensing analysis of MACSJ0717.5+3745 from Hubble Frontier Fields observations: How well can the mass distribution be constrained?

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

We present a strong-lensing analysis of MACSJ0717.5+3745 (hereafter MACS J0717), based on the full depth of the Hubble Frontier Field (HFF) observations, which brings the number of multiply imaged systems to 61, ten of which have been spectroscopically con ...

Edp Sciences S A2016

Are long gamma-ray bursts biased tracers of star formation? Clues from the host galaxies of the Swift/BAT6 complete sample of bright LGRBs II. Star formation rates and metallicities at z < 1

Hakim Atek

Aims. Long gamma-ray bursts (LGRBs) are associated with the deaths of massive stars and might therefore be a potentially powerful tool for tracing cosmic star formation. However, especially at low redshifts (z < 1.5) LGRBs seem to prefer particular types o ...

Edp Sciences S A2016

The Spitzer-Irac/Mips Extragalactic Survey (Simes) In The South Ecliptic Pole Field

Hakim Atek

We present the Spitzer-IRAC/MIPS Extragalactic survey (SIMES) in the South Ecliptic Pole field. The large area covered (7.7 deg(2)), together with one of the lowest Galactic cirrus emissions in the entire sky and a very extensive coverage by Spitzer, Hersc ...

Iop Publishing Ltd2016

The extraordinary amount of substructure in the Hubble Frontier Fields cluster Abell 2744

Johan Richard, Céline Tchernin, Jean-Paul Richard Kneib, Huanyuan Shan, Hakim Atek, Richard Massey, Markus Rexroth, David Richard Harvey, Mathilde Jauzac, Benjamin Yvan Alexandre Clement

We present a joint optical/X-ray analysis of the massive galaxy cluster Abell 2744 (z = 0.308). Our strong- and weak-lensing analysis within the central region of the cluster, i.e. at R < 1 Mpc from the brightest cluster galaxy, reveals eight substructures ...

Oxford Univ Press2016

The Lyman alpha reference sample VII. Spatially resolved H alpha kinematics

Hakim Atek

We present integral field spectroscopic observations with the Potsdam Multi-Aperture Spectrophotometer of all 14 galaxies in the z similar to 0.1 Lyman Alpha Reference Sample (LARS). We produce 2D line-of-sight velocity maps and velocity dispersion maps fr ...

Edp Sciences S A2016

Hubble Frontier Fields: predictions for the return of SN Refsdal with the MUSE and GMOS spectrographs

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

We present a high-precision mass model of the galaxy cluster MACS J1149.6+ 2223, based on a strong gravitational lensing analysis of Hubble Space Telescope Frontier Fields (HFF) imaging data and spectroscopic follow-up with Gemini/Gemini Multi-Object Spect ...

Oxford Univ Press2016

Hubble Frontier Fields: the geometry and dynamics of the massive galaxy cluster merger MACSJ0416.1-2403

Johan Richard, Jean-Paul Richard Kneib, Hakim Atek, Richard Massey, Markus Rexroth, David Richard Harvey, Mathilde Jauzac, Benjamin Yvan Alexandre Clement

We use a joint optical/X-ray analysis to constrain the geometry and history of the ongoing merging event in the massive galaxy cluster MACSJ0416.1-2403 (z = 0.397). Our investigation of cluster substructure rests primarily on a combined strong-and weak-len ...

Wiley-Blackwell2015

The Lyman alpha reference sample IV. Morphology at low and high redshift

Hakim Atek

Context. The transport of Ly alpha photons in galaxies is a complex process and the conditions under which Ly alpha photons manage to escape from certain galaxies is still under investigation. The Lyman alpha reference sample (LARS) is a sample of 14 local ...

EDP Sciences2015

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

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

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

Hubble Frontier Fields: a high-precision strong-lensing analysis of the massive galaxy cluster Abell 2744 using similar to 180 multiple images

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

We present a high-precision mass model of galaxy cluster Abell 2744, based on a strong gravitational-lensing analysis of the Hubble Space Telescope Frontier Fields (HFF) imaging data, which now include both Advanced Camera for Surveys and Wide Field Camera ...

Oxford University Press2015

Uvudf: Ultraviolet Through Near-Infrared Catalog And Photometric Redshifts Of Galaxies In The Hubble Ultra Deep Field

Hakim Atek

We present photometry and derived redshifts from up to eleven bandpasses for 9927 galaxies in the Hubble Ultra Deep field (UDF), covering an observed wavelength range from the near-ultraviolet (NUV) to the near-infrared (NIR) with Hubble Space Telescope ob ...

Institute of Physics2015

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

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

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

THE LYMAN ALPHA REFERENCE SAMPLE V. THE IMPACT OF NEUTRAL ISM KINEMATICS AND GEOMETRY ON Ly alpha ESCAPE

Hakim Atek

We present high-resolution far-UV spectroscopy of the 14 galaxies of the Ly alpha Reference Sample; a sample of strongly star-forming galaxies at low redshifts (0.028 < z < 0.18). We compare the derived properties to global properties derived from multi-ba ...

American Astronomical Society2015

THE Ly alpha REFERENCE SAMPLE. I. SURVEY OUTLINE AND FIRST RESULTS FOR MARKARIAN 259

Hakim Atek

The Ly alpha Reference Sample (LARS) is a substantial program with the Hubble Space Telescope (HST) that provides a sample of local universe laboratory galaxies in which to study the detailed astrophysics of the visibility and strength of the Ly alpha line ...

American Astronomical Society2014