Search Publications

The ARCiS framework for exoplanet atmospheres. Modelling philosophy and retrieval
DOI: 10.1051/0004-6361/201937377 Bibcode: 2020A&A...642A..28M

Helling, Christiane; Min, Michiel; Ormel, Chris W. +2 more


Aims: We present ARCiS, a novel code for the analysis of exoplanet transmission and emission spectra. The aim of the modelling framework is to provide a tool able to link observations to physical models of exoplanet atmospheres.
Methods: The modelling philosophy chosen in this paper is to use physical and chemical models to constrain cer…

2020 Astronomy and Astrophysics
eHST 79
Strong biases in retrieved atmospheric composition caused by day-night chemical heterogeneities
DOI: 10.1051/0004-6361/202037678 Bibcode: 2020A&A...636A..66P

Parmentier, Vivien; Leconte, Jérémy; Pluriel, William +1 more

Most planets currently amenable to transit spectroscopy are close enough to their host stars to exhibit a relatively strong day to night temperature gradient. For hot planets this leads to a chemical composition dichotomy between the two hemispheres. In the extreme case of ultra-hot Jupiters, some species, such as molecular hydrogen and water, are…

2020 Astronomy and Astrophysics
eHST 79
Modelling the He I triplet absorption at 10 830 Å in the atmosphere of HD 209458 b
DOI: 10.1051/0004-6361/201937175 Bibcode: 2020A&A...636A..13L

Alonso-Floriano, F. J.; Sánchez-López, A.; López-Puertas, M. +16 more

Context. HD 209458 b is an exoplanet with an upper atmosphere undergoing blow-off escape that has mainly been studied using measurements of the Lyα absorption. Recently, high-resolution measurements of absorption in the He I triplet line at 10 830 Å of several exoplanets (including HD 209458 b) have been reported, creating a new opportunity to pro…

2020 Astronomy and Astrophysics
eHST 77
Stellar rotation periods from K2 Campaigns 0-18. Evidence for rotation period bimodality and simultaneous variability decrease
DOI: 10.1051/0004-6361/201936887 Bibcode: 2020A&A...635A..43R

Reinhold, Timo; Hekker, Saskia

Context. Rotation period measurements of stars observed with the Kepler mission have revealed a lack of stars at intermediate rotation periods, accompanied by a decrease of photometric variability. Whether this so-called dearth region is a peculiarity of stars in the Kepler field, or reflects a general manifestation of stellar magnetic activity, i…

2020 Astronomy and Astrophysics
Gaia 77
Non-detection of TiO and VO in the atmosphere of WASP-121b using high-resolution spectroscopy
DOI: 10.1051/0004-6361/201937409 Bibcode: 2020A&A...636A.117M

Hooton, M. J.; Gibson, N. P.; Sing, D. K. +9 more

Thermal inversions have long been predicted to exist in the atmospheres of ultra-hot Jupiters. However, the detection of two species thought to be responsible - titanium oxide and vanadium oxide - remains elusive. We present a search for TiO and VO in the atmosphere of the ultra-hot Jupiter WASP-121b (Teq ≳ 2400 K), an exoplanet with ev…

2020 Astronomy and Astrophysics
Gaia 77
HOLISMOKES. II. Identifying galaxy-scale strong gravitational lenses in Pan-STARRS using convolutional neural networks
DOI: 10.1051/0004-6361/202038219 Bibcode: 2020A&A...644A.163C

Suyu, S. H.; Lemon, C.; Cañameras, R. +6 more

We present a systematic search for wide-separation (with Einstein radius θE ≳ 1.5″), galaxy-scale strong lenses in the 30 000 deg2 of the Pan-STARRS 3π survey on the Northern sky. With long time delays of a few days to weeks, these types of systems are particularly well-suited for catching strongly lensed supernovae with spat…

2020 Astronomy and Astrophysics
eHST 77
Planetary system LHS 1140 revisited with ESPRESSO and TESS
DOI: 10.1051/0004-6361/202038922 Bibcode: 2020A&A...642A.121L

Deleuil, M.; Barrado, D.; Bonfils, X. +17 more

Context. LHS 1140 is an M dwarf known to host two transiting planets at orbital periods of 3.77 and 24.7 days. They were detected with HARPS and Spitzer. The external planet (LHS 1140 b) is a rocky super-Earth that is located in the middle of the habitable zone of this low-mass star. All these properties place this system at the forefront of the h…

2020 Astronomy and Astrophysics
Gaia 76
MIRACLES: atmospheric characterization of directly imaged planets and substellar companions at 4-5 µm. I. Photometric analysis of β Pic b, HIP 65426 b, PZ Tel B, and HD 206893 B
DOI: 10.1051/0004-6361/201937159 Bibcode: 2020A&A...635A.182S

Quanz, S. P.; Todorov, K. O.; Stolker, T. +6 more

Context. Directly imaged planets and substellar companions are key targets for the characterization of self-luminous atmospheres. Their photometric appearance at 4-5 µm is sensitive to the chemical composition and cloud content of their atmosphere.
Aims: We aim to systematically characterize the atmospheres of directly imaged low-mass c…

2020 Astronomy and Astrophysics
AKARI Gaia 76
The MUSE Hubble Ultra Deep Field Survey. XIII. Spatially resolved spectral properties of Lyman α haloes around star-forming galaxies at z > 3
DOI: 10.1051/0004-6361/201937339 Bibcode: 2020A&A...635A..82L

Bacon, Roland; Blaizot, Jérémy; Garel, Thibault +18 more

We present spatially resolved maps of six individually-detected Lyman α haloes (LAHs) as well as a first statistical analysis of the Lyman α (Lyα) spectral signature in the circum-galactic medium of high-redshift star-forming galaxies (-17.5 > MUV > -21.5) using the Multi-Unit Spectroscopic Explorer. Our resolved spectroscopic ana…

2020 Astronomy and Astrophysics
eHST 75
Models and data analysis tools for the Solar Orbiter mission
DOI: 10.1051/0004-6361/201935305 Bibcode: 2020A&A...642A...2R

Fedorov, A.; Budnik, E.; Williams, D. +102 more

Context. The Solar Orbiter spacecraft will be equipped with a wide range of remote-sensing (RS) and in situ (IS) instruments to record novel and unprecedented measurements of the solar atmosphere and the inner heliosphere. To take full advantage of these new datasets, tools and techniques must be developed to ease multi-instrument and multi-spacec…

2020 Astronomy and Astrophysics
SOHO SolarOrbiter 75