Rotational and Rotational-Vibrational Raman Spectroscopy of Air to Characterize Astronomical Spectrographs

Vogt, Frédéric P. A.; Kerber, Florian; Mehner, Andrea; Yu, Shanshan; Pfrommer, Thomas; Lo Curto, Gaspare; Figueira, Pedro; Parraguez, Diego; Pepe, Francesco A.; Mégevand, Denis; Riva, Marco; Di Marcantonio, Paolo; Lovis, Christophe; Amate, Manuel; Molaro, Paolo; Cabral, Alexandre; Osorio, Maria Rosa Zapatero
Bibliographical reference

Physical Review Letters, Volume 123, Issue 6, id.061101

Advertised on:
8
2019
Number of authors
17
IAC number of authors
1
Citations
8
Refereed citations
7
Description
Raman scattering enables unforeseen uses for the laser guide-star system of the Very Large Telescope. Here, we present the observation of one up-link sodium laser beam acquired with the ESPRESSO spectrograph at a resolution λ /Δ λ ˜140 000 . In 900 s on source, we detect the pure rotational Raman lines of 16O2, 14N2, and 14N 15N (tentatively) up to rotational quantum numbers J of 27, 24, and 9, respectively. We detect the 16O2 fine-structure lines induced by the interaction of the electronic spin S and end-over-end rotational angular momentum N in the electronic ground state of this molecule up to N =9 . The same spectrum also reveals the ν1 ←0 rotational-vibrational Q-branch for 16O2 and 14N2 14. These observations demonstrate the potential of using laser guide-star systems as accurate calibration sources for characterizing new astronomical spectrographs.
Type