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Concept

Galaxie irrégulière

Publications associées (32)

ShapePipe: A new shape measurement pipeline and weak-lensing application to UNIONS/CFIS data

Austin Chandler Peel

Context. The Ultraviolet Near-Infrared Optical Northern Survey (UNIONS) is an ongoing collaboration that will provide the largest deep photometric survey of the northern sky in four optical bands to date. As part of this collaboration, the Canada-France Im ...

EDP SCIENCES S A2022

Nuclear star cluster formation in star-forming dwarf galaxies

Oliver Müller

Nuclear star clusters (NSCs) are massive star clusters found in all types of galaxies from dwarfs to massive galaxies. Recent studies show that while low-mass NSCs in dwarf galaxies (M-gal< 10(9)M(circle dot)) form predominantly out of the merger of globul ...

EDP SCIENCES S A2022

Next generation modeling techniques for strong gravitational lensing and measuring the Hubble constant

Aymeric Alexandre Galan

For many years, observations of the Universe suggest a series problems with our theoretical models, particularly its dark energy and dark matter components. Fortunately, the Universe also provides us with a tool to solve these problems, called strong gravi ...

EPFL2022

Advances in constraining intrinsic alignment models with hydrodynamic simulations

Jonathan Andrew Blazek

We use galaxies from the ILLUSTRISTNG, MASSIVEBLACK-II, and ILLUSTRTS-1 hydrodynamic simulations to investigate the behaviour of large scale galaxy intrinsic alignments. Our analysis spans four redshift slices over the approximate range of contemporary len ...

2021

Origin of stellar prolate rotation in a cosmologically simulated faint dwarf galaxy

Pascale Jablonka, Yves Revaz

Stellar prolate rotation in dwarf galaxies is rather uncommon, with only two known galaxies in the Local Group showing such feature (Phoenix and And II). Cosmological simulations show that in massive early-type galaxies prolate rotation likely arises from ...

OXFORD UNIV PRESS2021

Zero-metallicity Hypernova Uncovered by an Ultra-metal-poor Star in the Sculptor Dwarf Spheroidal Galaxy*

Pascale Jablonka

Although true metal-free "Population III" stars have so far escaped discovery, their nature, and that of their supernovae, is revealed in the chemical products left behind in the next generations of stars. Here we report the detection of an ultra-metal-poo ...

IOP PUBLISHING LTD2021

Towards Efficient and Accurate Numerical Simulations of Galaxies using Task-based Parallelism and Application to Dwarf Galaxies

Loïc Hausammann

Numerical simulations are of a tremendous help to understand the growth of non-linear cosmological structures and how they lead to the formation of galaxies. In recent years, with the goal of improving their prediction power, new hydrodynamical techniques ...

EPFL2021

The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey quasar sample: testing observational systematics on the Baryon Acoustic Oscillation measurement

Cheng Zhao

Baryon Acoustic Oscillations (BAO) are considered to be a very robust standard ruler against various systematics. This premise has been tested against observational systematics, but not to the level required for the next generation of galaxy surveys such a ...

OXFORD UNIV PRESS2021

Reducing the variance of redshift space distortion measurements from mock galaxy catalogues with different lines of sight

Cheng Zhao

Accuratemock catalogues are essential for assessing systematics in the cosmological analysis of large galaxy surveys. Anisotropic two-point clustering measurements from the same simulation show some scatter for different lines of sight (LOS), but are on av ...

OXFORD UNIV PRESS2021

Kinematic and metallicity properties of the Aquarius dwarf galaxy from FORS2 MXU spectroscopy

Pascale Jablonka

Context. Dwarf galaxies found in isolation in the Local Group (LG) are unlikely to have interacted with the large LG spirals, and therefore environmental effects such as tidal and ram-pressure stripping should not be the main drivers of their evolution. Ai ...

EDP SCIENCES S A2020

Chromosome maps of young LMC clusters: an additional case of coeval multiple populations

Carmela Lardo

Recent studies have revealed that the multiple populations (MPs) phenomenon does not occur only in ancient and massive Galactic globular clusters (GCs), but it is also observed in external galaxies, where GCs sample a wide age range with respect to the Mil ...

OXFORD UNIV PRESS2020

Constraining the primordial magnetic field with dwarf galaxy simulations

Pascale Jablonka, Yves Revaz, Salim Bennouna, Mahsa Sanati

Using a set of cosmological hydro-dynamical simulations, we constrained the properties of primordial magnetic fields by studying their impact on the formation and evolution of dwarf galaxies. We performed a large set of simulations (8 dark matter only and ...

EDP SCIENCES S A2020