Grimm, SL;
Malik, M;
Kitzmann, D;
Guzmán-Mesa, A;
Hoeijmakers, HJ;
Fisher, C;
Mendonca, JM;
... Heng, K; + view all
(2021)
HELIOS-K 2.0 Opacity Calculator and Open-source Opacity Database for Exoplanetary Atmospheres.
Astrophysical Journal Supplement
, 253
(1)
, Article 30. 10.3847/1538-4365/abd773.
Preview |
Text
2101.02005v1.pdf - Accepted Version Download (12MB) | Preview |
Abstract
Computing and using opacities is a key part of modeling and interpreting data of exoplanetary atmospheres. Since the underlying spectroscopic line lists are constantly expanding and currently include up to ~1010–1011 transition lines, the opacity calculator codes need to become more powerful. Here we present major upgrades to the HELIOS-K GPU-accelerated opacity calculator and describe the necessary steps to process large line lists within a reasonable amount of time. Besides performance improvements, we include more capabilities and present a toolbox for handling different atomic and molecular data sets, from downloading and preprocessing the data to performing the opacity calculations in a user-friendly way. HELIOS-K supports line lists from ExoMol, HITRAN, HITEMP, NIST, Kurucz, and VALD3. By matching the resolution of 0.1 cm−1 and cutting length of 25 cm−1 used by the ExoCross code for timing performance (251 s excluding data read-in time), HELIOS-K can process the ExoMol BT2 water line list in 12.5 s. Using a resolution of 0.01 cm−1, it takes 45 s, equivalent to about 107 lines s−1. As a wavenumber resolution of 0.01 cm−1 suffices for most exoplanetary atmosphere spectroscopic calculations, we adopt this resolution in calculating opacity functions for several hundred atomic and molecular species and make them freely available on the open-access DACE database. For the opacity calculations of the database, we use a cutting length of 100 cm−1 for molecules and no cutting length for atoms. Our opacities are available for downloading from https://dace.unige.ch/opacityDatabase and may be visualized using https://dace.unige.ch/opacity.
| Type: | Article |
|---|---|
| Title: | HELIOS-K 2.0 Opacity Calculator and Open-source Opacity Database for Exoplanetary Atmospheres |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-4365/abd773 |
| Publisher version: | https://doi.org/10.3847/1538-4365/abd773 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Planets and satellites: atmospheres |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10119694 |
Archive Staff Only
 |
View Item |
