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Publications associées (23)

Evolution of the Size-Mass Relation of Star-forming Galaxies Since z=5.5 Revealed by CEERS

Michaela Hirschmann

We combine deep imaging data from the CEERS early release JWST survey and Hubble Space Telescope imaging from CANDELS to examine the size-mass relation of star-forming galaxies and the morphology-quenching relation at stellar masses M-star >= 10(9.5)M(circ ...

Iop Publishing Ltd2024

The Pristine survey - XXI. Exploring the metal-poor boundary with ESPaDoNS

Pascale Jablonka

In this paper, we study high-resolution spectra of 19 stars that have metallicity estimates below -3.5 using at least two metallicity-sensitive photometric indices based on Pristine photometry. The purpose is to understand what kind of stars populate this ...

OXFORD UNIV PRESS2023

HD 213258: A new rapidly oscillating, super slowly rotating, strongly magnetic Ap star in a spectroscopic binary

Pierre North

We report on HD 213258, an Ap star that we recently identified as presenting a unique combination of rare, remarkable properties. Our study of this star is based on ESPaDOnS Stokes I and V data obtained at seven epochs spanning a time interval slightly sho ...

EDP SCIENCES S A2023

Discovery of a Binary-origin Classical Cepheid in a Binary System with a 59 day Orbital Period

Richard Irving Anderson

We report the discovery of a surprising binary configuration of the double-mode Cepheid OGLE-LMC-CEP-1347 pulsating in the first (P-1= 0.690 days) and second-overtone (P-2= 0.556 days) modes. The orbital period (P-orb= 59 days) of the system is five times ...

Iop Publishing Ltd2022

Do the majority of stars form as gravitationally unbound?

Richard Irving Anderson

Context. Some of the youngest stars (age less than or similar to 10 Myr) are clustered, while many others are observed scattered throughout star forming regions or in complete isolation. It has been intensively debated whether such scattered or isolated st ...

2022

Cepheids with Giant Companions. I. Revealing a Numerous Population of Double-lined Binary Cepheids* (dagger)

Richard Irving Anderson

Masses of classical Cepheids of 3-11 M are predicted by theory but those measured clump between 3.6-5 M. As a result, their mass-luminosity relation is poorly constrained, impeding our understanding of basic stellar physics and the Leavitt Law. All Cepheid ...

2021

Homotopical relations between 2-dimensional categories and their infinity-analogues

Lyne Moser

In this thesis, we study the homotopical relations of 2-categories, double categories, and their infinity-analogues. For this, we construct homotopy theories for the objects of interest, and show that there are homotopically full embeddings of 2-categories ...

EPFL2021

Spectroscopic Orbits Of Three Dwarf Barium Stars

Pierre North

Barium stars are thought to result from binary evolution in systems wide enough to allow the more massive component to reach the asymptotic giant branch and eventually become a CO white dwarf. While Ba stars were initially known only among giant or subgian ...

OBSERVATORY2020

Barium and related stars, and their white-dwarf companions

Pierre North, Conrad Johnston, Shreeya Sushil Shetye

Barium (Ba) dwarfs and CH subgiants are the less evolved analogues of Ba and CH giants. They are F- to G-type main-sequence stars polluted with heavy elements by their binary companions when the companion was on the asymptotic giant branch (AGB). This comp ...

EDP SCIENCES S A2019

The Pristine survey II: A sample of bright stars observed with FEROS

Pascale Jablonka

Extremely metal-poor (EMP) stars are old objects formed in the first Gyr of the Universe. They are rare and, to select them the most successful strategy has been to build on large and low-resolution spectroscopic surveys. The combination of narrow- and bro ...

Wiley-V C H Verlag Gmbh2017

Detecting unresolved binary stars in Euclid VIS images

Frédéric Courbin, Thibault Adrien Kuntzer

Measuring a weak gravitational lensing signal to the level required by the next generation of space-based surveys demands exquisite reconstruction of the point-spread function (PSF). However, unresolved binary stars can significantly distort the PSF shape. ...

Edp Sciences S A2017

Evaluating the effect of stellar multiplicity on the point spread function of space-based weak lensing surveys

Frédéric Courbin, Georges Meylan, Thibault Adrien Kuntzer

The next generation of space-based telescopes used for weak lensing surveys will require exquisite point spread function (PSF) determination. Previously negligible effects may become important in the reconstruction of the PSF, in part because of the improv ...

Edp Sciences S A2016

The Time-Domain Spectroscopic Survey: Understanding The Optically Variable Sky With Sequels In Sdss-Iii

Jean-Paul Richard Kneib

The Time-Domain Spectroscopic Survey (TDSS) is an SDSS-IV eBOSS subproject primarily aimed at obtaining identification spectra of similar to 220,000 optically variable objects systematically selected from SDSS/Pan-STARRS1 multi-epoch imaging. We present a ...

Iop Publishing Ltd2016

Design of Single-Molecule Magnets: Insufficiency of the Anisotropy Barrier as the Sole Criterion

Jan Gui-Hyon Dreiser

Determination of the electronic energy spectrum of a trigonalsymtnetry mononuclear Yb3+ single-molecule magnet (SMM) by highresolution absorption and luniinescente spectroscopies reveals that the first excited electronic doublet is placed nearly 500 cm(-1) ...

American Chemical Society2015

SALSA: a tool to estimate the stray light contamination for low-Earth orbit observatories

Thibault Adrien Kuntzer

Stray light contamination reduces considerably the precision of photometric of faint stars for low altitude space-borne observatories. When measuring faint objects, the necessity of coping with stray light contamination arises in order to avoid systematic ...

Spie-Int Soc Optical Engineering2014

[C II] and 12CO (1-0) emission maps in HLSJ091828. 6+ 514223: a strongly lensed interacting system at z= 5.24

Jean-Paul Richard Kneib, Benjamin Yvan Alexandre Clement

We present Submillimeter Array [ C II] 158 mu m and Karl G. Jansky Very Large Array (CO)-C-12(1-0) line emission maps for the bright, lensed, submillimeter source at z = 5.2430 behind A 773: HLSJ091828.6+514223 (HLS0918). We combine these measurements with ...

American Astronomical Society2014

A 7 deg(2) survey for galaxy-scale gravitational lenses with the HST imaging archive(star)

Frédéric Courbin, Georges Meylan

We present the results of a visual search for galaxy-scale gravitational lenses in similar to 7 deg(2) of Hubble Space Telescope (HST) images. The data set comprises the whole imaging data ever taken with the Advanced Camera for Surveys (ACS) in the filter ...

Wiley-Blackwell2014

Image Analysis For Cosmology: Results From The Great10 Star Challenge

Frédéric Courbin, Georges Meylan, Marc Gentile

We present the results from the first public blind point-spread function (PSF) reconstruction challenge, the GRavitational lEnsing Accuracy Testing 2010 (GREAT10) Star Challenge. Reconstruction of a spatially varying PSF, sparsely sampled by stars, at non- ...

University of Chicago Press2013

The ESPRI project: astrometric exoplanet search with PRIMA I. Instrument description and performance of first light observations

Ludger Weber

Context. The ESPRI project relies on the astrometric capabilities offered by the PRIMA facility of the Very Large Telescope Interferometer for discovering and studying planetary systems. Our survey consists of obtaining high-precision astrometry for a larg ...

Edp Sciences S A2013

A deep proper-motion survey of the nearby open cluster Blanco 1

Jean-Claude Mermilliod

We provide two comprehensive catalogues of positions and proper motions in the area of open cluster Blanco 1. The main catalogue, CtlgM, contains 6271 objects down to V similar to 18.5 and covers a circular similar to 11 deg2 area. The accuracy of CtlgM pr ...

Blackwell Publishing Ltd, Oxford2011