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Concept

Star system

Related publications (31)

GHOST commissioning science results - II: a very metal-poor star witnessing the early galactic assembly

Pascale Jablonka

This study focuses on Pristine_180956.78-294759.8 (hereafter P180956, [Fe/H] = -1.95 +/- 0.02), a star selected from the Pristine Inner Galaxy Survey (PIGS), and followed-up with the recently commissioned Gemini High-resolution Optical SpecTrograph (GHOST) ...

Oxford Univ Press2024

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 PHANGS-JWST Treasury Survey: Star Formation, Feedback, and Dust Physics at High Angular Resolution in Nearby GalaxieS

Robin Gopala Tress

The PHANGS collaboration has been building a reference data set for the multiscale, multiphase study of star formation and the interstellar medium (ISM) in nearby galaxies. With the successful launch and commissioning of JWST, we can now obtain high-resolu ...

IOP Publishing Ltd2023

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

Emission-line properties of IllustrisTNG galaxies: from local diagnostic diagrams to high-redshift predictions for JWST

Michaela Hirschmann, Adèle Marie Françoise Plat

We compute synthetic, rest-frame optical and ultraviolet (UV) emission-line properties of galaxy populations at redshifts from z approximate to 0 to =8 in a full cosmological framework. We achieve this by coupling, in post-processing, the cosmological Illu ...

Oxford Univ Press2023

Near-infrared emission line diagnostics for AGN from the local Universe to z ∼ 3

Michaela Hirschmann

Optical rest-frame spectroscopic diagnostics are usually employed to distinguish between star formation and active galactic nucleus (AGN) powered emission. However, this method is biased against dusty sources, hampering a complete census of the AGN populat ...

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

The first generations of stars in the Local Group

Romain Ely Roland Lucchesi

The different projects of this thesis contribute to improving our understanding of the early chemical evolution of the galaxies. The standard cosmological model states an hierarchical formation of the galaxies, the dwarf galaxies being the first stellar sy ...

EPFL2022

TOCOSMO VIII. A key test of systematics in the hierarchical method of time-delay cosmography

Frédéric Courbin

The largest source of systematic errors in the time-delay cosmography method likely arises from the lens model mass distribution, where an inaccurate choice of model could in principle bias the value of H-0. A Bayesian hierarchical framework has been propo ...

EDP SCIENCES S A2022

The eta Aquilae System: Radial Velocities and Astrometry in Search of eta Aql B

Richard Irving Anderson

The classical Cepheid eta Aql was not included in past Leavitt Law work because of a presumed complicating orbit due to a known B9.8V companion. To determine the orbit of eta Aql B, we analyze a significant number of radial velocity (RV) measurements from ...

2022

HD 60431, the CP2 star with the shortest rotational period Physical parameters and period analysis

Pierre North

Context. CP2 stars show periodic photometric, spectroscopic, and magnetic variations with the rotational period. They are generally slow rotators, with rotational periods exceeding half a day, except for the late B-type star HD 60431, which has an unusuall ...

EDP SCIENCES S A2022

UNITSIM-Galaxies: data release and clustering of emission-line galaxies

Ginevra Favole

New surveys such as European Space Agencys (ESA's) Euclid mission are planned to map with unprecedented precision the large-scale structure of the Universe by measuring the 3D positions of tens of millions of galaxies. It is necessary to develop theoretica ...

OXFORD UNIV PRESS2022

A birth-death-migration model for life in astrophysical environments

Claudio Grimaldi

To assess the number of life-bearing worlds in astrophysical environments, it is necessary to take the intertwined processes of abiogenesis (birth), extinction (death), and transfer of life (migration) into account. We construct a mathematical model that i ...

OXFORD UNIV PRESS2021

The GOGREEN Survey: Evidence of an Excess of Quiescent Disks in Clusters at 1.0

Pascale Jablonka, Hung-Hsu Chan

We present the results of the measured shapes of 832 galaxies in 11 galaxy clusters at 1.0 < z < 1.4 from the GOGREEN survey. We measure the axis ratio (q), the ratio of the minor to the major axis, of the cluster galaxies from near-infrared Hubble Space T ...

IOP Publishing Ltd2021

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

Cold gas in the cosmic web around galaxy clusters

Damien Louis Alexandre Spérone-Longin

Galaxies live in very different types of environment. Those different environments are relics from the evolution of the Universe since the Big Bang. This network of structures observed via large scale surveys is called Cosmic Web. Within this web, galaxies ...

EPFL2021

SEEDisCS: I. Molecular gas in galaxy clusters and their large-scale structure: The case of CL1411.1-1148 at z similar to 0.5

Pascale Jablonka, Gianluca Castignani, Damien Louis Alexandre Spérone-Longin

We investigate how the galaxy reservoirs of molecular gas fuelling star formation are transformed while the host galaxies infall onto galaxy cluster cores. As part of the Spatially Extended ESO Distant Cluster Survey (SEEDisCS), we present CO(3-2) observat ...

EDP SCIENCES S A2021

Quantifying the information impact of future searches for exoplanetary biosignatures

Claudio Grimaldi

One of the major goals for astronomy in the next decades is the remote search for biosignatures (i.e., the spectroscopic evidence of biological activity) in exoplanets. Here we adopt a Bayesian statistical framework to discuss the implications of such futu ...

National Academy of Sciences2020

Molecular gas in CLASH brightest cluster galaxies at z similar to 0.2-0.9

Pascale Jablonka, Gianluca Castignani

Brightest cluster galaxies (BCGs) are excellent laboratories for the study of galaxy evolution in dense Mpc-scale environments. We used the IRAM-30 m to observe, in CO(1 -> 0), CO(2 -> 1), CO(3 -> 2), or CO(4 -> 3), 18 BCGs at z similar to 0.2-0.9 drawn fr ...

EDP SCIENCES S A2020

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