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Concept

Spectroscopie astronomique

Publications associées (32)

Methylidyne Adsorption on Pt(211) Probed by Reflection Absorption Infrared Spectroscopy (RAIRS)

Rainer Beck, Ana Gutiérrez González, Harmina Vejayan

Methylidyne, CH(ads), adsorbed on a Pt(211) surface and its interaction with chemisorbed hydrogen atoms was studied by reflection absorption infrared spectroscopy (RAIRS). Methylidyne was formed on Pt(211) by methane dissociation from a molecular beam foll ...

2022

H I constraints from the cross-correlation of eBOSS galaxies and Green Bank Telescope intensity maps

Jean-Paul Richard Kneib

We present the joint analysis of Neutral Hydrogen (H I) Intensity Mapping observations with three galaxy samples: the Luminous Red Galaxy (LRG) and Emission Line Galaxy (ELG) samples from the eBOSS survey, and the WiggleZ Dark Energy Survey sample. The H I ...

OXFORD UNIV PRESS2022

Removing systematics-induced 21-cm foreground residuals by cross-correlating filtered data

Tianyue Chen

Observations of the redshifted 21-cm signal emitted by neutral hydrogen represent a promising probe of large-scale structure in the universe. However, the cosmological 21-cm signal is challenging to observe due to astrophysical foregrounds which are severa ...

American Physical Society2022

In Situ Infrared Spectroscopy of NOx Reduction Catalysts: A Laboratory Exercise for In-Person and Virtual Learning

Oliver Kröcher, Davide Ferri, Rob Jeremiah G. Nuguid

Infrared (IR) spectroscopy and catalysis represent two of the most practically relevant topics in chemistry, but they are normally taught in separate contexts at the undergraduate level. Although IR spectroscopy is introduced to students as a tool for orga ...

AMER CHEMICAL SOC2022

Multi-gas spectroscopy using tailored mid-IR dispersive wave generated in Si3N4 waveguide

Camille Sophie Brès, Davide Grassani, Fan Yang, Eirini Tagkoudi

We demonstrate simultaneous detection of acetylene, methane and ethane using milliwatt-level dispersive-wave generated in a Si3N4 waveguide covering 2900 cm-1-3380 cm-1 spectral region. This simple mid-IR absorption spectroscopy scheme achieves hundreds of ...

2021

Supercontinuum generation in silicon nitride (Si_3N_4) waveguides for middle infrared spectroscopy

Eirini Tagkoudi

The middle-infrared (mid-IR) spectral range hosts the most intense roto-vibrational absorption lines of many important molecules. Particularly, mid-IR spectroscopy constitutes a unique tool for identifying and quantifying molecular species through their mi ...

EPFL2021

Photo- and thermally-induced electronic and structural dynamics in perovskites and transition metal oxides

Oliviero Cannelli

In this thesis, we exploited optical and X-ray pump-probe methods in a synergistic approach to study the interplay of the electronic, spin and structural degrees of freedom in two class of complex systems relevant for solar energy conversion applications: ...

EPFL2021

Direct observation of multiband transport in magnonic Penrose quasicrystals via broadband and phase-resolved spectroscopy

Dirk Grundler, Mohammad Hamdi, Korbinian Baumgärtl, Sho Watanabe, Vinayak Shantaram Bhat

Quasicrystals are aperiodically ordered structures with unconventional rotational symmetry. Their peculiar features have been explored in photonics to engineer bandgaps for light waves. Magnons (spin waves) are collective spin excitations in magnetically o ...

2021

Learning convergence prediction of astrobots in multi-object spectrographs

Denis Gillet, Jean-Paul Richard Kneib, Matin Macktoobian

Astrobot swarms are used to capture astronomical signals to generate the map of the observable universe for the purpose of dark energy studies. The convergence of each swarm in the course of its coordination has to surpass a particular threshold to yield a ...

2021

Dissociative Sticking Probability of Methane on Pt(110)-(2×1)

Rainer Beck, Ana Gutiérrez González

In this work, we revisit the dissociative sticking of methane on Pt(110)-(2×1) using quasi-classical trajectory (QCT) calculations and supersonic molecular beam (SMB) experiments. Experimentally, we apply the King and Wells method and the reflection absorp ...

2021

Measurement of the 2D emission profiles of hydrogen and impurity ions in the TCV divertor

Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Kevin Henricus Annemarie Verhaegh, Mirko Wensing, Artur Perek

Plasma emission of hydrogen and impurities is measured with use of filtered camera imaging in TCV divertor. The measurement technique is discussed in detail including: selection choice of filters, the absolute calibration procedure and the tomographic inve ...

Elsevier2021

Broadband Optical Spectrum Downconversion to RF Using Integrated Dual-Comb Source

Andrey Voloshin

Combining all the benefits of Fourier transform infrared (FTIR) spectroscopy in a chip scale spectroscopic sensor looks promising for mobile and wearable platform development. Dual-comb spectroscopy enables downconversion of optical absorption spectra into ...

IEEE2021