Fundamental physics with ESPRESSO: a new determination of the D/H ratio towards PKS1937-101

Guarneri, Francesco; Pasquini, Luca; D'Odorico, Valentina; Cristiani, Stefano; Cupani, Guido; Di Marcantonio, Paolo; González Hernández, J. I.; Martins, C. J. A. P.; Suárez Mascareño, Alejandro; Milaković, Dinko; Molaro, Paolo; Murphy, Michael T.; Nunes, Nelson J.; Palle, Enric; Pepe, Francesco; Rebolo, Rafael; Santos, Nuno C.; Génova Santos, Ricardo; Schmidt, Tobias M.; Sousa, Sérgio G.; Sozzetti, Alessandro; Trost, Andrea
Bibliographical reference

Monthly Notices of the Royal Astronomical Society

Advertised on:
4
2024
Number of authors
22
IAC number of authors
5
Citations
2
Refereed citations
0
Description
Primordial abundances of light elements are sensitive to the physics of the early Universe and can directly constrain cosmological quantities, such as the baryon-to-photon ratio $\eta _{10}$, the baryon density, and the number of neutrino families. Deuterium is especially suited for these studies: its primordial abundance is sensitive and monotonically dependent on $\eta _{10}$, allowing an independent measurement of the cosmic baryon density that can be compared, for instance, against the Planck satellite data. The primordial deuterium abundance can be measured in high H I column density absorption systems towards distant quasars. We report here a new measurement, based on high-resolution ESPRESSO data, of the primordial D I abundance of a system at redshift $z \sim 3.572$, towards PKS1937-101. Using only ESPRESSO data, we find a D /H ratio of $2.638\pm 10^{-5}$, while including the available UVES data improves the precision, leading to a ratio of $2.608 \pm 10^{-5}$. The results of this analysis agree with those of the most precise existing measurements. We find that the relatively low column density of this system ($\log {N_{\rm H_I}/ {\rm cm}^{-2}}\sim 18$) introduces modelling uncertainties, which become the main contributor to the error budget.