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Concept

Raie à 21 centimètres

Publications associées (31)

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: N-body mock challenge for the eBOSS emission line galaxy sample

Cheng Zhao, Anand Stéphane Raichoor, Amélie Tamone

Cosmological growth can be measured in the redshift space clustering of galaxies targeted by spectroscopic surveys. Accurate prediction of clustering of galaxies will require understanding galaxy physics, which is a very hard and highly non-linear problem. ...

OXFORD UNIV PRESS2021

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: measurement of the BAO and growth rate of structure of the emission line galaxy sample from the anisotropic power spectrum between redshift 0.6 and 1.1

Cheng Zhao, Anand Stéphane Raichoor, Amélie Tamone, Claudio Gorgoni

We analyse the large-scale clustering in Fourier space of emission line galaxies (ELG) from the Data Release 16 of the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey. The ELG sample contains 173736 galaxies covering 1170deg(2) ...

OXFORD UNIV PRESS2021

Constraining dark photons and their connection to 21 cm cosmology with CMB data

Kyrylo Bondarenko

In the inhomogeneous Universe, the cosmological conversion of dark photons into ordinary photons (and vice versa) may happen at a great number of resonance redshifts. This alters the CMB observed energy spectrum and degree of small-scale anisotropies. We u ...

2020

Time-resolved formation of excited atomic and molecular states in XUV-induced nanoplasmas in ammonia clusters

Marcel Drabbels, Andrew Daniel Bonnar Clark, Verónica Oliver Álvarez de Lara

High intensity XUV radiation from a free-electron laser (FEL) was used to create a nanoplasma inside ammonia clusters with the intent of studying the resulting electron-ion interactions and their interplay with plasma evolution. In a plasma-like state, ele ...

ROYAL SOC CHEMISTRY2020

Validation of emission-line galaxies target selection algorithms for the Dark Energy Spectroscopic Instrument using the MMT Binospec

Anand Stéphane Raichoor

The forthcoming Dark Energy Spectroscopic Instrument (DESI) experiment plans to measure the effects of dark energy on the expansion of the Universe and create a 3D map of the Universe using galaxies up to z similar to 1.6 and QSOs up to z similar to 3.5. I ...

OXFORD UNIV PRESS2020

The completed SDSS-IV extended baryon oscillation spectroscopic survey: growth rate of structure measurement from anisotropic clustering analysis in configuration space between redshift 0.6 and 1.1 for the emission-line galaxy sample

Jean-Paul Richard Kneib, Cheng Zhao, Anand Stéphane Raichoor, Amélie Tamone, Claudio Gorgoni

We present the anisotropic clustering of emission-line galaxies (ELGs) from the Sloan Digital Sky Survey IV (SDSS-IV) extended Baryon Oscillation Spectroscopic Survey (eBOSS) Data Release 16 (DR16). Our sample is composed of 173 736 ELGs covering an area o ...

OXFORD UNIV PRESS2020

Investigation of the fine structure of antihydrogen

Shirit Cohen, Juan Mario Michan

At the historic Shelter Island Conference on the Foundations of Quantum Mechanics in 1947, Willis Lamb reported an unexpected feature in the fine structure of atomic hydrogen: a separation of the 2S(1/2) and 2P(1/2) states(1). The observation of this separ ...

2020

21-cm observations and warm dark matter models

Alexey Boyarsky, Oleg Ruchayskiy, Wessel Valkenburg

Observations of the redshifted 21-cm signal (in absorption or emission) allow us to peek into the epoch of the "Dark Ages" and the onset of reionization. These data can provide a novel way to learn about the nature of dark matter, in particular, about the ...

American Physical Society2019

Quasi-stellar objects acting as potential strong gravitational lenses in the SDSS-III BOSS survey

Jean-Paul Richard Kneib, Frédéric Courbin, Timothée Guy Olivier Delubac

We present a sample of 12 quasi-stellar objects (QSOs) that potentially act as strong gravitational lenses on background emission line galaxies (ELG) or Lyman-alpha emitters (LAEs) selected through a systematic search of the 297 301 QSOs in the Sloan Digit ...

EDP SCIENCES S A2019

Observation of the 1S-2P Lyman-alpha transition in antihydrogen

Shirit Cohen

In 1906, Theodore Lyman discovered his eponymous series of transitions in the extreme-ultraviolet region of the atomic hydrogen spectrum(1,2). The patterns in the hydrogen spectrum helped to establish the emerging theory of quantum mechanics, which we now ...

Nature Publishing Group2018

Spectroscopic investigations of divertor detachment in TCV

Basil Duval, Holger Reimerdes, Benoît Labit, Nicola Vianello, Federico Nespoli, Christian Gabriel Theiler, Umar Sheikh, Cedric Kar-Wai Tsui, Kevin Henricus Annemarie Verhaegh, Wouter Vijvers, Roberto Maurizio, Claudio Marini

The aim of this work is to provide an understanding of detachment at TCV with emphasis on analysis of the Balmer line emission. A new Divertor Spectroscopy System has been developed for this purpose. Further development of Balmer line analysis techniques h ...

Elsevier2017