368 citations · 4.4k across the 47 of their papers we have counts for
46 papers · 1 filter
More Realistic Planetesimal Masses Alter Kuiper Belt Formation Models and Add Stochasticity
Nathan A. Kaib, Alex Parsells, Simon Grimm +2
We perform simulations here that include the gravitational effects of the primordial planetesimal belt consisting of ~10^5 massive bodies. In our simulations, Neptune unlocks from…
Speeding up the GENGA N-body integrator on consumer-grade graphics cards
R. Brasser, S. L. Grimm, P. Hatalova +1
GPU computing is popular due to the calculation potential of a single card. The N-body integrator GENGA is built to for this, but it suffers a performance penalty on consumer-grade…
Time-resolved transmission spectroscopy of the ultra-hot Jupiter WASP-189 b
Bibiana Prinoth, H. Jens Hoeijmakers, Stefan Pelletier +14
Ultra-hot Jupiters are tidally locked with their host stars dividing their atmospheres into a hot dayside and a colder nightside. As the planet moves through transit, different reg…
Terrestrial planet formation from a ring
J. M. Y. Woo, A. Morbidelli, S. L. Grimm +2
It has been long proposed that, if all the terrestrial planets form within a tiny ring of solid material at around 1 AU, the concentrated mass-distance distribution of the current…
The THOR+HELIOS general circulation model: multi-wavelength radiative transfer with accurate scattering by clouds/hazes
Russell Deitrick, Kevin Heng, Urs Schroffenegger +5
General circulation models (GCMs) provide context for interpreting multi-wavelength, multi-phase data of the atmospheres of tidally locked exoplanets. In the current study, the non…
GENGA II: GPU planetary N-body simulations with non-Newtonian forces and high number of particles
Simon L. Grimm, Joachim G. Stadel, Ramon Brasser +2
We present recent updates and improvements of the graphical processing unit (GPU) N-body code GENGA. Modern state-of-the-art simulations of planet formation require the use of a ve…
The Mantis Network I: A standard grid of templates and masks for cross-correlation analyses of ultra-hot Jupiter transmission spectra
Daniel Kitzmann, Jens H. Hoeijmakers, Simon L. Grimm +3
The atmospheres of ultra-hot Jupiters are highly interesting and unique chemical laboratories. Due to the very high atmospheric temperatures, their chemical composition is dominate…
An upper limit on late accretion and water delivery in the Trappist-1 exoplanet system
Sean N. Raymond, Andre Izidoro, Emeline Bolmont +9
The Trappist-1 system contains seven roughly Earth-sized planets locked in a multi-resonant orbital configuration, which has enabled precise measurements of the planets' masses and…
Titanium oxide and chemical inhomogeneity in the atmosphere of the exoplanet WASP-189b
Bibiana Prinoth, H. Jens Hoeijmakers, Daniel Kitzmann +21
The temperature of an atmosphere decreases with increasing altitude, unless a shortwave absorber exists that causes a temperature inversion. Ozone plays this role in the Earth`s at…
3D radiative-transfer for exoplanet atmospheres. gCMCRT: a GPU accelerated MCRT code
Elspeth K. H. Lee, Joost P. Wardenier, Bibiana Prinoth +10
Radiative-transfer (RT) is a key component for investigating atmospheres of planetary bodies. With the 3D nature of exoplanet atmospheres being important in giving rise to their ob…
The terrestrial planet formation paradox inferred from high-resolution N-body simulations
Jason Man Yin Woo, Ramon Brasser, Simon L. Grimm +2
Recent improvements to GPU hardware and the symplectic N-body code GENGA allow for unprecedented resolution in simulations of planet formation. In this paper, we report results fro…
Simulating gas giant exoplanet atmospheres with Exo-FMS: Comparing semi-grey, picket fence and correlated-k radiative-transfer schemes
Elspeth K. H. Lee, Vivien Parmentier, Mark Hammond +5
Radiative-transfer (RT) is a fundamental part of modelling exoplanet atmospheres with general circulation models (GCMs). An accurate RT scheme is required for estimates of the atmo…
Mars' formation can constrain the primordial orbits of the gas giants
Jason Man Yin Woo, Joachim Stadel, Simon Grimm +1
Recent high precision meteoritic data infers that Mars finished its accretion rapidly within 10 Myr of the beginning of the Solar system and had an accretion zone that did not enti…
Growing Mars fast: High-resolution GPU simulations of embryo formation
Jason Man Yin Woo, Simon L. Grimm, Ramon Brasser +1
Recent high precision meteoritic data improve constraints on the formation timescale and bulk composition of the terrestrial planets. High resolution N-body simulations allow direc…
HELIOS-K 2.0 Opacity Calculator and Open-source Opacity Database for Exoplanetary Atmospheres
Simon L. Grimm, Matej Malik, Daniel Kitzmann +12
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 an…
An N-body population synthesis framework for the formation of moons around Jupiter-like planets
Marco Cilibrasi, Judit Szulágyi, Simon L. Grimm +1
The moons of giant planets are believed to form in situ in Circumplanetary Discs (CPDs). Here we present an N-body population synthesis framework for satellite formation around a J…
Refining the transit timing and photometric analysis of TRAPPIST-1: Masses, radii, densities, dynamics, and ephemerides
Eric Agol, Caroline Dorn, Simon L. Grimm +32
We have collected transit times for the TRAPPIST-1 system with the Spitzer Space Telescope over four years. We add to these ground-based, HST and K2 transit time measurements, and…
A super-Earth and a sub-Neptune orbiting the bright, quiet M3 dwarf TOI-1266
B. -O. Demory, F. J. Pozuelos, Y. Gomez Maqueo Chew +70
We report the discovery and characterisation of a super-Earth and a sub-Neptune transiting the bright (), quiet, and nearby (37 pc) M3V dwarf TOI-1266. We validate the plane…
Information content of JWST-NIRSPEC transmission spectra of warm Neptunes
Andrea Guzmán-Mesa, Daniel Kitzmann, Chloe Fisher +7
Warm Neptunes offer a rich opportunity for understanding exo-atmospheric chemistry. With the upcoming James Webb Space Telescope (JWST), there is a need to elucidate the balance be…
High-resolution Transmission Spectroscopy of MASCARA-2 b with EXPRES
H. Jens Hoeijmakers, Samuel H. C. Cabot, Lily Zhao +10
We report detections of atomic species in the atmosphere of MASCARA-2 b, using the first transit observations obtained with the newly commissioned EXPRES spectrograph. EXPRES is a…
On the impact of tides on the transit-timing fits to the TRAPPIST-1 system
Emeline Bolmont, Brice-Olivier Demory, Sergi Blanco-Cuaresma +5
Transit Timing Variations, or TTVs, can be a very efficient way of constraining masses and eccentricities of multi-planet systems. Recent measurements of the TTVs of TRAPPIST-1 led…
THOR 2.0: Major Improvements to the Open-Source General Circulation Model
Russell Deitrick, João M. Mendonça, Urs Schroffenegger +3
THOR is the first open-source general circulation model (GCM) developed from scratch to study the atmospheres and climates of exoplanets, free from Earth- or Solar System-centric t…
Interpreting High-Resolution Spectroscopy of Exoplanets Using Cross-Correlations and Supervised Machine Learning
Chloe Fisher, H. Jens Hoeijmakers, Daniel Kitzmann +4
We present a new method for performing atmospheric retrieval on ground-based, high-resolution data of exoplanets. Our method combines cross-correlation functions with a random fore…
Helios-r2 -- A new Bayesian, open-source retrieval model for brown dwarfs and exoplanet atmospheres
Daniel Kitzmann, Kevin Heng, Maria Oreshenko +5
We present an improved, hybrid CPU-GPU atmospheric retrieval code, Helios-r2, which is applicable to medium-resolution emission spectra of brown dwarfs, in preparation for precisio…