J/A+A/609/A34 VUV absorption cross section of CO_2_ (Venot+, 2018) ================================================================================ VUV-absorption cross section of carbon dioxide from 150 to 800 K and applications to warm exoplanetary atmospheres. Venot O., Benilan Y., Fray N., Gazeau M.-C., Lefevre F., Es-sebbar Et., Hebrard E., Schwell M., Bahrini C., Montmessin F., Lefevre M., Waldmann I.P. =2018A&A...609A..34V (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Atomic physics ; Spectra, ultraviolet Keywords: molecular data - methods: laboratory: molecular - planets and satellites: atmospheres Abstract: We quantify the temperature dependency of the VUV absorption cross section of carbon dioxide. The VUV absorption cross section of CO_2_ increases with the temperature. The absorption we measured at 150K seems to be close to the absorption of CO_2_ in the fundamental ground state. The absorption cross section can be separated in two parts: a continuum and a fine structure superimposed on the continuum. The variation of the continuum of absorption can be represented by the sum of three gaussian functions. We used these data in our 1D thermo-photochemical model in order to study their impact on the predicted atmospheric composition of warm exoplanets. Using data at high temperature in thermo-photochemical models modifies significantly the abundance and the photodissociation rates of many species, in addition to carbon dioxide, such as methane and ammonia. These deviations have an impact on synthetic transmission spectra, leading to variations of up to 5ppm. Description: We performed experimental measurements of CO_2_ absorption cross section with synchrotron radiation for the wavelength range (115-200nm). For longer wavelengths (195-230nm), we used a deuterium lamp and a 1.5m Jobin-Yvon spectrometer. We present a full set of high resolution ({Delta}{lambda}=0.03nm) absorption cross sections of CO_2_ from 115 to 230nm for temperatures ranging from 150 to 800K. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file co2_150k.dat 22 1985 Absorption cross section of CO_2_ at 150K co2_170k.dat 22 2154 Absorption cross section of CO_2_ at 170K co2_195k.dat 22 2345 Absorption cross section of CO_2_ at 195K co2_230k.dat 22 2367 Absorption cross section of CO_2_ at 230K co2_300k.dat 22 2167 Absorption cross section of CO_2_ at 300K co2_420k.dat 22 2040 Absorption cross section of CO_2_ at 420K co2_500k.dat 22 2101 Absorption cross section of CO_2_ at 500K co2_585k.dat 22 3031 Absorption cross section of CO_2_ at 585K co2_700k.dat 22 3127 Absorption cross section of CO_2_ at 700K co2_800k.dat 22 3394 Absorption cross section of CO_2_ at 800K -------------------------------------------------------------------------------- Byte-by-byte Description of file: co2*.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 9 F9.5 nm lambda [114/230] Wavelength 12- 22 E11.5 cm2 CS Absorption cross section -------------------------------------------------------------------------------- Acknowledgements: Olivia Venot, olivia.venot(at)lisa.u-pec.fr ================================================================================ (End) Olivia Venot [LISA, France], Patricia Vannier [CDS] 26-Sep-2017