Publications associées à Exoplanète

New insight on the nature of cosmic reionizers from the CEERS survey

The Epoch of Reionization (EoR) began when galaxies grew in abundance and luminosity, so their escaping Lyman continuum (LyC) radiation started ionizing the surrounding neutral intergalactic medium (IGM). Despite significant recent progress, the nature and ...

Edp Sciences S A2024

The Pristine dwarf galaxy survey-V. The edges of the dwarf galaxy Hercules

Pascale Jablonka, Nicolas Lawrence Etienne Longeard

We present a new spectroscopic study of 175 stars in the vicinity of the dwarf galaxy Hercules (d similar to 132 kpc) with data from the Anglo-Australian Telescope and its AAOmega spectrograph together with the Two Degree Field multi-object system to solve ...

OXFORD UNIV PRESS2023

Euclid preparation XXX. Performance assessment of the NISP red grism through spectroscopic simulations for the wide and deep surveys

Frédéric Courbin, Georges Meylan, Gianluca Castignani, Michaela Hirschmann, Maurizio Martinelli, Yi Wang, Richard Massey, Fabio Finelli, Marcello Farina

This work focusses on the pilot run of a simulation campaign aimed at investigating the spectroscopic capabilities of the Euclid NearInfrared Spectrometer and Photometer (NISP), in terms of continuum and emission line detection in the context of galaxy evo ...

EDP SCIENCES S A2023

The Pristine survey - XX. GTC follow-up observations of extremely metal-poor stars identified from Pristine and LAMOST

Pascale Jablonka

A B S T R A C T Ultra-metal-poor stars ( [Fe / H] < -4 . 0) are very rare, and finding them is a challenging task. Both narrow-band photometry and low-resolution spectroscopy have been useful tools for identifying candidates, and in this work, we combine b ...

OXFORD UNIV PRESS2023

A Highly Magnified Gravitationally Lensed Red QSO at z = 2.5 with a Significant Flux Ratio Anomaly

Hung-Hsu Chan

We present the discovery of a gravitationally lensed dust-reddened QSO at z = 2.517, identified in a survey for QSOs by infrared selection. Hubble Space Telescope imaging reveals a quadruply lensed system in a cusp configuration, with a maximum image separ ...

2023

Constraining quasar structure using high-frequency microlensing variations and continuum reverberation

Frédéric Courbin, Eric Gérard Guy Paic, Hung-Hsu Chan, Vivien François Bonvin, Georgios Vernardos, Martin Raoul Robert Millon

Gravitational microlensing is a powerful tool for probing the inner structure of strongly lensed quasars and for constraining parameters of the stellar mass function of lens galaxies. This is achieved by analysing microlensing light curves between the mult ...

EDP SCIENCES S A2022

The Pristine dwarf galaxy survey - IV. Probing the outskirts of the dwarf galaxy Bootes I

Pascale Jablonka, Nicolas Lawrence Etienne Longeard, Romain Ely Roland Lucchesi

We present a new spectroscopic study of the dwarf galaxy Bootes I (Boo I) with data from the Anglo-Australian Telescope and its AAOmega spectrograph together with the Two Degree Field multi-object system. We observed 36 high-probability Boo I stars selecte ...

OXFORD UNIV PRESS2022

Genomic Diversity of Torque Teno Virus in Blood Samples from Febrile Paediatric Outpatients in Tanzania: A Descriptive Cohort Study

Mary-Anne Hartley

Torque teno virus (TTV) is considered to be an ubiquitous member of the commensal human blood virome commonly reported in mixed genotype co-infections. This study investigates the genomic diversity of TTV in blood samples from 816 febrile Tanzanian childre ...

MDPI2022

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

Reflectivity of Venus's Dayside Disk During the 2020 Observation Campaign: Outcomes and Future Perspectives

Stephan Hellmich

We performed a unique Venus observation campaign to measure the disk brightness of Venus over a broad range of wavelengths in 2020 August and September. The primary goal of the campaign was to investigate the absorption properties of the unknown absorber i ...

IOP Publishing Ltd2022

The Effects of Planetary and Stellar Parameters on Brittle Lithospheric Thickness

Marie Estelle Solange Violay, Michael Heap

The thicknesss of the brittle lithosphere—the outer portion of a planetary body that fails via fracturing— plays a key role in the geological processes of that body. The properties of both a planet and its host star can influence that thickness, and the po ...

2021

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

Recent advances in superconducting nanowire single-photon detector technology for exoplanet transit spectroscopy in the mid-infrared

Simone Frasca

The Origins Space Telescope mission concept includes an exoplanet transit spectrometer that requires detector arrays with ultrahigh pixel-to-pixel stability. Superconducting nanowire single-photon detectors, or SNSPDs, have the potential to meet these stri ...

SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS2021

The GOGREEN survey: transition galaxies and the evolution of environmental quenching

Pascale Jablonka, Hung-Hsu Chan

We measure the rate of environmentally driven star formation quenching in galaxies at z similar to 1, using eleven massive () galaxy clusters spanning a redshift range 1.0 < z < 1.4 from the GOGREEN sample. We identify three different types of transition g ...

OXFORD UNIV PRESS2021

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

A Microlensing Accretion Disk Size Measurement in the Lensed Quasar WFI 2026-4536

Frédéric Courbin, Vivien François Bonvin, Martin Raoul Robert Millon

We use 13 seasons of R-band photometry from the 1.2 m Leonard Euler Swiss Telescope at La Silla to examine microlensing variability in the quadruply imaged lensed quasar WFI 2026-4536. The lightcurves exhibit similar to 0.2 mag of uncorrelated variability ...

IOP PUBLISHING LTD2020

Overview of the FTU results

Cristian Galperti, Gabriele Grosso, Filippo Bagnato

Since the 2016 IAEA Fusion Energy Conference, FTU operations have been mainly devoted to experiments on runaway electrons and investigations into a tin liquid limiter; other experiments have involved studies of elongated plasmas and dust. The tearing mode ...

IOP Publishing Ltd2019

A microphotonic astrocomb

Tobias Kippenberg, Michael Wolfgang Geiselmann, Junqiu Liu, Tobias Herr, Miles Henry Anderson, Stefan Kundermann

Earth-like planets, dark energy and variability of fundamental physical constants can be discovered by observing wavelength shifts in the optical spectra of astronomical objects(1-5). These wavelength shifts are so tiny that exquisitely accurate and precis ...

Nature Publishing Group2019

Daylight Discomfort Glare Evaluation with Evalglare: Influence of Parameters and Methods on the Accuracy of Discomfort Glare Prediction

Jan Wienold, Clotilde Marie A Pierson, Magali Bodart

Nowadays, discomfort glare indices are frequently calculated by using evalglare. Due to the lack of knowledge on the implications of the methods and parameters of evalglare, the default settings are often used. But wrong parameter settings can lead to inap ...

2018

Pristine dwarf galaxy survey - I. A detailed photometric and spectroscopic study of the very metal-poor Draco II satellite

Pascale Jablonka, Silvia Martin de Nicolas Agut, Nicolas Lawrence Etienne Longeard

We present a detailed study of the faint Milky Way satellite Draco II (Dra II) from deep CFHT/MegaCam broad-band g and i photometry and narrow-band metallicity-sensitive CaliK observations, along with follow-up Keck II/DEIMOS multi-object spectroscopy. For ...

OXFORD UNIV PRESS2018