Fundamental physics with ESPRESSO: Towards an accurate wavelength calibration for a precision test of the fine-structure constant
Year: 2020
Type: article
Abstract: Observations of metal absorption systems in the spectra of distant quasars allow one to constrain a possible variation of the fine-structure constant throughout the history of the Universe. Such a test poses utmost demands on the wavelength accuracy and previous studies were limited by systematics in the spectrograph wavelength calibration. A substantial advance in the field is therefore expected from the new ultra-stable high-resolution spectrograph E SPRESSO , which was recently installed at the VLT. In preparation of the fundamental physics related part of the E SPRESSO GTO program, we present a thorough assessment of the E SPRESSO wavelength accuracy and identify possible systematics at each of the different steps involved in the wavelength calibration process. Most importantly, we compare the default wavelength solution, which is based on the combination of Thorium-Argon arc lamp spectra and a Fabry-Pérot interferometer, to the fully independent calibration obtained from a laser frequency comb. We find wavelength-dependent discrepancies of up to 24 m s −1 . This substantially exceeds the photon noise and highlights the presence of different sources of systematics, which we characterize in detail as part of this study. Nevertheless, our study demonstrates the outstanding accuracy of E SPRESSO with respect to previously used spectrographs and we show that constraints of a relative change of the fine-structure constant at the 10 −6 level can be obtained with E SPRESSO without being limited by wavelength calibration systematics.
Source: Astronomy and Astrophysics
Authors: Tobias M. Schmidt, Paolo Molaro, Michael T. Murphy, Christophe Lovis, Guido Cupani, Stefano Cristiani, Francesco A. Pepe, Rafael Rebolo, Nuno C. Santos, Manuel Abreu, Vardan Adibekyan, Yann Alibert, Matteo Aliverti, Romain Allart, Carlos Allende Prieto, David Alves, Veronica Baldini, Christopher Broeg, Alexandre Cabral, Giorgio Calderone, Roberto Cirami, João Coelho, Igor Coretti, Valentina D’Odorico, Paolo Di Marcantonio, David Ehrenreich, Pedro Figueira, Matteo Genoni, Ricardo Génova Santos, Jonay I. González Hernández, Florian Kerber, Marco Landoni, Ana C. O. Leite, Jean-Louis Lizon, Gaspare Lo Curto, Antonio Manescau, Carlos J. A. P. Martins, Denis Megévand, Andrea Mehner, Giuseppina Micela, Andrea Modigliani, Manuel Monteiro, Mario J. P. F. G. Monteiro, Eric Mueller, Nelson J. Nunes, Luca Oggioni, António Oliveira, Giorgio Pariani, Luca Pasquini, Edoardo Redaelli, Marco Riva, Pedro Santos, Danuta Sosnowska, Sérgio G. Sousa, Alessandro Sozzetti, Alejandro Suárez Mascareño, Stéphane Udry, Maria-Rosa Zapatero Osorio, Filippo Zerbi
Institutions: University of Geneva, Trieste Astronomical Observatory, Institute for Fundamental Physics of the Universe, Swinburne University of Technology, Universidad de La Laguna, Instituto de Astrofísica de Canarias, Universidade do Porto, Institute of Astrophysics and Space Sciences, University of Lisbon, Centro de Astrofísica da Universidade do Porto, University of Bern, Brera Astronomical Observatory, Istituto di Radioastronomia di Bologna, Center for Space and Habitability, European Southern Observatory, European Southern Observatory, Osservatorio Astronomico di Cagliari, National Institute for Astrophysics, Osservatorio Astronomico di Palermo, Osservatorio Astrofisico di Torino, Centro de Astrobiología
Language: English
Subfield: Instrumentation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: G1037624341, G1059456037, G1297482482, G132494354, G1516346500, G1763632427, G1807621157, G2166381293, Orogenic growth in the atlas mountains of SW Marocco - Insights from low-temperature thermochronometry and in situ cosmogenic dating, Le problème de l'intuition., G274581676, G2761687731, Testing fundamental physics with solar twin stars, Instituto de Astrofísica e Ciências do Espaço, Instituto de Astrofísica e Ciências do Espaço, G3661801348, G368632804, G3696820176, G3840324753, G3891694003, G4192228184, G428931209, G434337789, G4430112794, G4724859719, G4855809565, G491858407, Phénomènes de transport et propriétés électroniques des métaux et des supraconducteurs, G5224927334, G526596183, G5454278309, G5499322367, G5677667711, A Geração de Espectrógrafos para encontrar uma nova Terra, G601864726, Wissenschaftliche Korrespondenz von Wolfgang Pauli, Band IV : 1950-1958, G6103259537, G6125752356, Cosmologia e Física Fundamental com o ESPRESSO, G6680474175, Instituto de Astrofísica e Ciências do Espaço, Explorando exoPlanetas com o CHEOPS, G7221734343, G7554324364, G7965899483, G830901801, G967088233
OpenAlex ID: W3206265719