Concept

Irregular galaxy

Related publications (83)

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

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 impact of the fiducial cosmology assumption on BAO distance scale measurements

Cheng Zhao, Paul Carter

Standard analysis pipelines for measurements of Baryon Acoustic Oscillations (BAO) in galaxy surveys make use of a fiducial cosmological model to guide the data compression required to transform from observed redshifts and angles to the measured angular an ...

OXFORD UNIV PRESS2020

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 chemical evolution of the dwarf spheroidal galaxy Sextans

Pascale Jablonka, Pierre North, Carmela Lardo, Romain Ely Roland Lucchesi, Romaine Theler

We present our analysis of the FLAMES dataset targeting the central 25 ' region of the Sextans dwarf spheroidal galaxy (dSph). This dataset is the third major part of the high-resolution spectroscopic section of the ESO large program 171.B-0588(A) obtained ...

EDP SCIENCES S A2020

Tracing the formation of the Milky Way through ultra metal-poor stars

Pascale Jablonka, Nicolas Lawrence Etienne Longeard

We use Gaia DR2 astrometric and photometric data, published radial velocities and MESA models to infer distances, orbits, surface gravities, and effective temperatures for all ultra metal-poor stars ([Fe/H] < -4.0 dex) available in the literature. Assuming ...

OXFORD UNIV PRESS2019

Weak-lensing shear measurement with machine learning Teaching artificial neural networks about feature noise

Frédéric Courbin, Thibault Adrien Kuntzer, Malte Tewes

Cosmic shear, that is weak gravitational lensing by the large-scale matter structure of the Universe, is a primary cosmological probe for several present and upcoming surveys investigating dark matter and dark energy, such as Euclid or WFIRST. The probe re ...

EDP SCIENCES S A2019

Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram

Stephan Morgenthaler, Mikaël Martino, Jean-Marie Petit, Shuangqing Liao

Context. The ESA Gaia mission provides a unique time-domain survey for more than 1.6 billion sources with G less than or similar to 21 mag. Aims. We showcase stellar variability in the Galactic colour-absolute magnitude diagram (CaMD). We focus on pulsatin ...

EDP SCIENCES S A2019

Observable tests of self-interacting dark matter in galaxy clusters: BCG wobbles in a constant density core

David Richard Harvey, Richard Massey

Models of cold dark matter (CDM) predict that the distribution of dark matter in galaxy clusters should be cuspy, centrally concentrated. Constant density cores would be strong evidence for beyond CDM physics, such as self-interacting dark matter (SIDM). A ...

OXFORD UNIV PRESS2019

Machine-learning Classifiers for Intermediate Redshift Emission-line Galaxies

Jean-Paul Richard Kneib, Johan Comparat, David Schlegel

Classification of intermediate redshift (z = 0.3-0.8) emission line galaxies as star-forming galaxies, composite galaxies, active galactic nuclei (AGNs), or low-ionization nuclear emission regions (LINERs) using optical spectra alone was impossible because ...

IOP PUBLISHING LTD2019

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

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