Publications associées à Stellar Metallicities and Gradients in the Faint M31 Satellites Andromeda XVI and Andromeda XXVIII

Publications associées (18)

Euclid: Early Release Observations – The intracluster light and intracluster globular clusters of the Perseus cluster

Frédéric Courbin, Georges Meylan, Yannick Michael Bahé

We study the intracluster light (ICL) and intracluster globular clusters (ICGCs) in the nearby Perseus cluster of galaxies using Euclid’s Early Release Observations. By modelling the isophotal and iso-density contours, we mapped the distributions and prope ...

2025

A Merging Pair of Massive Quiescent Galaxies at z=3.44 in the Cosmic Vine

Michaela Hirschmann, Marion Nancy Amandine Farcy

We report the spectroscopic confirmation of a merging pair of massive quiescent galaxies at z = 3.44. Using JWST observations, we confirm that the two galaxies lie at a projected separation of 4.5 kpc with a velocity offset of similar to 680 km s(-1) (delt ...

EDP SCIENCES S A2025

The Ionizing Photon Production Efficiency of Star-forming Galaxies at z ∼ 4-10

Michaela Hirschmann

Context. Investigating the ionizing emission of star-forming galaxies and the escape fraction of ionizing photons is critical to understanding their contribution to reionization and their impact on the surrounding environment. The number of ionizing photon ...

EDP Sciences SA2025

The effect of measurement uncertainties on the inferred stability of planes of satellite galaxies

Salvatore Taibi

Context. Observations have revealed that the Milky Way, Andromeda, Centaurus A, and possibly other galaxies host spatially thin and kinematically coherent planes of satellites. Such structures are highly improbable within the standard ΛCDM cosmological mod ...

2025

Finding gravitational lenses at the dawn of the new generation of wide-field surveys

Javier Alejandro Acevedo Barroso

Strong gravitational lensing has become one of the main astrophysical probes of the extragalactic universe. It allows precise measurements of deflector galaxy masses. It acts as a cosmic telescope, revealing sources otherwise too dim or small to study. Whe ...

EPFL2025

Evidence of star cluster migration and merger in dwarf galaxies

Oliver Müller

Nuclear star clusters (NSCs) are the densest stellar systems in the Universe. These clusters can be found at the centre of all galaxy types but tend to favour galaxies of intermediate stellar mass around 109M⊙ (refs. 1,2). At present, two main processes ar ...

2025

The VELOCE modulation zoo III. Detecting additional pulsation modes in optical spectra of classical Cepheids using semi-partial distance correlation periodograms

Kent Barbey, Richard Irving Anderson, Giordano Viviani

Known for their large amplitude radial pulsations, classical Cepheids are critical standard candles in astrophysics. However, they also exhibit various pulsational irregularities and additional signals that provide deeper insights into their structure and ...

2025

The KALEIDOSCOPE survey: a new strong and weak gravitational lensing view of the massive galaxy cluster MACS J1423.8+2404

Benjamin Emmanuel Nicolas Beauchesne

We present a combined strong and weak gravitational-lensing analysis of the massive galaxy cluster MACS J1423.8+2404 (z = 0.545, MACS J1423 hereafter), one of the most dynamically relaxed and massive cool-core clusters discovered in the MAssive Cluster Sur ...

2024

Chemical cartography of the Milky Way

Richard Irving Anderson

Context. The motion of stars has been used to reveal details of the complex history of the Milky Way, in constant interaction with its environment. Nevertheless, to reconstruct the Galactic history puzzle in its entirety, the chemo-physical characterisatio ...

EDP SCIENCES S A2023

Precision Modeling of JWST's First Cluster Lens SMACS J0723.3-7327*

Jean-Paul Richard Kneib, Benjamin Yvan Alexandre Clement, Benjamin Emmanuel Nicolas Beauchesne

Exploiting the fundamentally achromatic nature of gravitational lensing, we present a lens model for the massive galaxy cluster SMACS J0723.3-7323 (SMACS J0723; z = 0.388) that significantly improves upon earlier work. Building on strong-lensing constraint ...

IOP Publishing Ltd2023

Euclid preparation XXV. The Euclid Morphology Challenge: Towards model-fitting photometry for billions of galaxies

Frédéric Courbin, Georges Meylan

The European Space Agency's Euclid mission will provide high-quality imaging for about 1.5 billion galaxies. A software pipeline to automatically process and analyse such a huge amount of data in real time is being developed by the Science Ground Segment o ...

EDP SCIENCES S A2023

Reeling in the Whirlpool galaxy: Distance to M 51 clarified through Cepheids and the type IIP supernova 2005cs

Richard Irving Anderson

Context. The distance to the Whirlpool galaxy, M 51, is still debated, even though the galaxy has been studied in great detail. Current estimates range from 6.02 to 9.09 Mpc, and different methods yield discrepant results. No Cepheid distance has been publ ...

2023

CEERS Epoch 1 NIRCam Imaging: Reduction Methods and Simulations Enabling Early JWST Science Results

Michaela Hirschmann

We present the data release and data reduction process for the Epoch 1 NIRCam observations for the Cosmic Evolution Early Release Science Survey (CEERS). These data consist of NIRCam imaging in six broadband filters (F115W, F150W, F200W, F277W, F356W and F ...

IOP Publishing Ltd2023

Dark Energy Survey year 3 results: Constraints on cosmological parameters and galaxy-bias models from galaxy clustering and galaxy-galaxy lensing using the redMaGiC sample

Jonathan Andrew Blazek

We constrain cosmological parameters and galaxy-bias parameters using the combination of galaxy clustering and galaxy-galaxy lensing measurements from the Dark Energy Survey (DES) year-3 data. We describe our modeling framework and choice of scales analyze ...

American Physical Society2022

Dark Energy Survey Year 3 results: Cosmology with moments of weak lensing mass maps

Jonathan Andrew Blazek

We present a cosmological analysis using the second and third moments of the weak lensing mass (convergence) maps from the first three years of data (Y3) data of the Dark Energy Survey. The survey spans an effective area of 4139 square degrees and uses the ...

American Physical Society2022

IX. Systematic comparison between lens modelling software programs:Time-delay prediction for WGD 2038-4008

Frédéric Courbin, Aymeric Alexandre Galan

The importance of alternative methods for measuring the Hubble constant, such as time-delay cosmography, is highlighted by the recent Hubble tension. It is paramount to thoroughly investigate and rule out systematic biases in all measurement methods before ...

EDP SCIENCES S A2022

The need for a multi-purpose, optical-NIR space facility after HST and JWST The case for an ESA-led HabEx Workhorse Camera

Frédéric Courbin

In the early 2030s, after the end of operations for the epochal Hubble Space Telescope and the long-anticipated James Webb Space Telescope, astrophysics will lose access to a general purpose high-spatial resolution space observatory to cover the UV-optical ...

SPRINGER2021

Astrophysical applications of gravitationally lensed quasars : from dark matter halos to the structure of quasar accretion disks

Alexander Patrick Eigenbrod

Gravitational lensing describes how light is deflected as it passes in the vicinity of a mass distribution. The amplitude of the deflection is proportional to the mass of the deflector, called "gravitational lens", and is generally weak, even for large mas ...

EPFL2008