All Outputs (81)

A Recent Impact Origin of Saturn’s Rings and Mid-sized Moons (2023)
Journal Article
Teodoro, L. F. A., Kegerreis, J. A., Estrada, P. R., Ćuk, M., Eke, V. R., Cuzzi, J. N., Massey, R. J., & Sandnes, T. D. (2023). A Recent Impact Origin of Saturn’s Rings and Mid-sized Moons. Astrophysical Journal, 955(2), Article 137. https://doi.org/10.3847/1538-4357/acf4ed

We simulate the collision of precursor icy moons analogous to Dione and Rhea as a possible origin for Saturn's remarkably young rings. Such an event could have been triggered a few hundred million years ago by resonant instabilities in a previous sat... Read More about A Recent Impact Origin of Saturn’s Rings and Mid-sized Moons.

Dealing with density discontinuities in planetary SPH simulations (2022)
Journal Article
Ruiz-Bonilla, S., Borrow, J., Eke, V., Kegerreis, J., Massey, R., Sandnes, T., & Teodoro, L. (2022). Dealing with density discontinuities in planetary SPH simulations. Monthly Notices of the Royal Astronomical Society, 512(3), 4660-4668. https://doi.org/10.1093/mnras/stac857

Density discontinuities cannot be precisely modelled in standard formulations of smoothed particles hydrodynamics (SPH) because the density field is defined smoothly as a kernel-weighted sum of neighbouring particle masses. This is a problem when per... Read More about Dealing with density discontinuities in planetary SPH simulations.

Measurement of the free neutron lifetime using the neutron spectrometer on NASA's Lunar Prospector mission (2021)
Journal Article
Wilson, J. T., Lawrence, D. J., Peplowski, P. N., Eke, V. R., & Kegerreis, J. A. (2021). Measurement of the free neutron lifetime using the neutron spectrometer on NASA's Lunar Prospector mission. Physical Review C, 104(4), Article 045501. https://doi.org/10.1103/physrevc.104.045501

We use data from the Lunar Prospector Neutron Spectrometer to make the second space-based measurement of the free neutron lifetime finding τ n = 887 ± 14 stat + 7 − 3 syst s, which is within 1 σ of the accepted value. This measurement expands the ran... Read More about Measurement of the free neutron lifetime using the neutron spectrometer on NASA's Lunar Prospector mission.

The surprising accuracy of isothermal Jeans modelling of self-interacting dark matter density profiles (2020)
Journal Article
Robertson, A., Massey, R., Eke, V., Schaye, J., & Theuns, T. (2021). The surprising accuracy of isothermal Jeans modelling of self-interacting dark matter density profiles. Monthly Notices of the Royal Astronomical Society, 501(3), 4610-5634. https://doi.org/10.1093/mnras/staa3954

Recent claims of observational evidence for self-interacting dark matter (SIDM) have relied on a semi-analytic method for predicting the density profiles of galaxies and galaxy clusters containing SIDM. We present a thorough description of this metho... Read More about The surprising accuracy of isothermal Jeans modelling of self-interacting dark matter density profiles.

The effect of pre-impact spin on the Moon-forming collision (2020)
Journal Article
Ruiz-Bonilla, S., Eke, V., Kegerreis, J., Massey, R., & Teodoro, L. (2021). The effect of pre-impact spin on the Moon-forming collision. Monthly Notices of the Royal Astronomical Society, 500(3), 2861-2870. https://doi.org/10.1093/mnras/staa3385

We simulate the hypothesized collision between the proto-Earth and a Mars-sized impactor that created the Moon. Among the resulting debris disc in some impacts, we find a self-gravitating clump of material. It is roughly the mass of the Moon, contain... Read More about The effect of pre-impact spin on the Moon-forming collision.

Atmospheric Erosion by Giant Impacts onto Terrestrial Planets: A Scaling Law for any Speed, Angle, Mass, and Density (2020)
Journal Article
Kegerreis, J., Eke, V., Catling, D., Massey, R., Teodoro, L., & Zahnle, K. (2020). Atmospheric Erosion by Giant Impacts onto Terrestrial Planets: A Scaling Law for any Speed, Angle, Mass, and Density. Astrophysical Journal Letters, 901(2), Article L31. https://doi.org/10.3847/2041-8213/abb5fb

We present a new scaling law to predict the loss of atmosphere from planetary collisions for any speed, angle, impactor mass, target mass, and body composition, in the regime of giant impacts onto broadly terrestrial planets with relatively thin atmo... Read More about Atmospheric Erosion by Giant Impacts onto Terrestrial Planets: A Scaling Law for any Speed, Angle, Mass, and Density.

Atmospheric Erosion by Giant Impacts onto Terrestrial Planets (2020)
Journal Article
Kegerreis, J., Eke, V., Massey, R., & Teodoro, L. (2020). Atmospheric Erosion by Giant Impacts onto Terrestrial Planets. Astrophysical Journal, 897(2), Article 161. https://doi.org/10.3847/1538-4357/ab9810

We examine the mechanisms by which the atmosphere can be eroded by giant impacts onto Earth-like planets with thin atmospheres, using 3D smoothed particle hydrodynamics simulations with sufficient resolution to directly model the fate of low-mass atm... Read More about Atmospheric Erosion by Giant Impacts onto Terrestrial Planets.

Space-based measurement of the neutron lifetime using data from the neutron spectrometer on NASA's MESSENGER mission (2020)
Journal Article
Wilson, J. T., Lawrence, D. J., Peplowski, P. N., Eke, V. R., & Kegerreis, J. A. (2020). Space-based measurement of the neutron lifetime using data from the neutron spectrometer on NASA's MESSENGER mission. Physical Review Research, 2(2), Article 023316. https://doi.org/10.1103/physrevresearch.2.023316

We establish the feasibility of measuring the neutron lifetime via an alternative, space-based class of methods, which use neutrons generated by galactic cosmic ray spallation of planets surfaces and atmospheres. Free neutrons decay via the weak inte... Read More about Space-based measurement of the neutron lifetime using data from the neutron spectrometer on NASA's MESSENGER mission.

Understanding the large inferred Einstein radii of observed low-mass galaxy clusters (2020)
Journal Article
Robertson, A., Massey, R., & Eke, V. (2020). Understanding the large inferred Einstein radii of observed low-mass galaxy clusters. Monthly Notices of the Royal Astronomical Society, 494(4), 4706-4712. https://doi.org/10.1093/mnras/staa1076

We assess a claim that observed galaxy clusters with mass ∼1014M⊙ are more centrally concentrated than predicted in lambda cold dark matter (ΛCDM). We generate mock strong gravitational lensing observations, taking the lenses from a cosmological hydr... Read More about Understanding the large inferred Einstein radii of observed low-mass galaxy clusters.

Observable tests of self-interacting dark matter in galaxy clusters: cosmological simulations with SIDM and baryons (2019)
Journal Article
Robertson, A., Harvey, D., Massey, R., Eke, V., McCarthy, I. G., Jauzac, M., …Schaye, J. (2019). Observable tests of self-interacting dark matter in galaxy clusters: cosmological simulations with SIDM and baryons. Monthly Notices of the Royal Astronomical Society, 488(3), 3646-3662. https://doi.org/10.1093/mnras/stz1815

We present BAHAMAS-SIDM, the first large-volume, (400 h−1 Mpc)3, cosmological simulations including both self-interacting dark matter (SIDM) and baryonic physics. These simulations are important for two primary reasons: 1) they include the effects of... Read More about Observable tests of self-interacting dark matter in galaxy clusters: cosmological simulations with SIDM and baryons.

Planetary Giant Impacts: Convergence of High-Resolution Simulations using Efficient Spherical Initial Conditions and SWIFT (2019)
Journal Article
Kegerreis, J., Eke, V., Gonnet, P., Korycansky, D., Massey, R., Schaller, M., & Teodoro, L. (2019). Planetary Giant Impacts: Convergence of High-Resolution Simulations using Efficient Spherical Initial Conditions and SWIFT. Monthly Notices of the Royal Astronomical Society, 487(4), 5029-5040. https://doi.org/10.1093/mnras/stz1606

We perform simulations of giant impacts onto the young Uranus using smoothed particle hydrodynamics (SPH) with over 100 million particles. This 100–1000 × improvement in particle number reveals that simulations with below 107 particles fail to conver... Read More about Planetary Giant Impacts: Convergence of High-Resolution Simulations using Efficient Spherical Initial Conditions and SWIFT.

Grid Mapping the Northern Plains of Mars: Geomorphological, Radar, and Water‐Equivalent Hydrogen Results From Arcadia Plantia (2018)
Journal Article
Ramsdale, J. D., Balme, M. R., Gallagher, C., Conway, S. J., Smith, I. B., Hauber, E., …Wilson, J. T. (2019). Grid Mapping the Northern Plains of Mars: Geomorphological, Radar, and Water‐Equivalent Hydrogen Results From Arcadia Plantia. Journal of Geophysical Research: Planets, 124(2), 504-527. https://doi.org/10.1029/2018je005663

A project of mapping ice‐related landforms was undertaken to understand the role of subsurface ice in the northern plains. This work is the first continuous regional mapping from CTX (ConTeXt Camera, 6 m/pixel; Malin et al., 2007) imagery in Arcadia... Read More about Grid Mapping the Northern Plains of Mars: Geomorphological, Radar, and Water‐Equivalent Hydrogen Results From Arcadia Plantia.

Grid Mapping the Northern Plains of Mars: A New Overview of Recent Water‐ and Ice‐Related Landforms in Acidalia Planitia (2018)
Journal Article
Orgel, C., Hauber, E., Gasselt, S., Reiss, D., Johnsson, A., Ramsdale, J. D., …Teodoro, L. F. (2019). Grid Mapping the Northern Plains of Mars: A New Overview of Recent Water‐ and Ice‐Related Landforms in Acidalia Planitia. Journal of Geophysical Research: Planets, 124(2), 454-482. https://doi.org/10.1029/2018je005664

We used a grid‐mapping technique to analyze the distribution of 13 water‐ and ice‐related landforms in Acidalia Planitia as part of a joint effort to study the three main basins in the northern lowlands of Mars, that is, Acidalia, Utopia, and Arcadia... Read More about Grid Mapping the Northern Plains of Mars: A New Overview of Recent Water‐ and Ice‐Related Landforms in Acidalia Planitia.

Unravelling the mystery of lunar anomalous craters using radar and infrared observations (2018)
Journal Article
Fa, W., & Eke, V. R. (2018). Unravelling the mystery of lunar anomalous craters using radar and infrared observations. Journal of Geophysical Research: Planets, 123(8), 2119-2137. https://doi.org/10.1029/2018je005668

In Miniature Radio Frequency (Mini‐RF) radar images, anomalous craters are those having a high circular polarization ratio (CPR) in their interior but not exterior to their rims. Previous studies found that most CPR‐anomalous craters contain permanen... Read More about Unravelling the mystery of lunar anomalous craters using radar and infrared observations.

Image Reconstruction Techniques in Neutron and Gamma-Ray Spectroscopy: Improving Lunar Prospector Data (2018)
Journal Article
Wilson, J., Lawrence, D., Peplowski, P., Cahill, J., Eke, V., Massey, R., & Teodoro, L. (2018). Image Reconstruction Techniques in Neutron and Gamma-Ray Spectroscopy: Improving Lunar Prospector Data. Journal of Geophysical Research: Planets, 123(7), 1804-1822. https://doi.org/10.1029/2018je005589

We present improved resolution maps of the Lunar Prospector Neutron Spectrometer thermal, epithermal, and fast neutron data and gamma ray spectrometer Th‐line fluxes via global application of pixon image reconstruction techniques. With the use of moc... Read More about Image Reconstruction Techniques in Neutron and Gamma-Ray Spectroscopy: Improving Lunar Prospector Data.

Consequences of Giant Impacts on Early Uranus for Rotation, Internal Structure, Debris, and Atmospheric Erosion (2018)
Journal Article
Kegerreis, J., Teodoro, L., Eke, V., Massey, R., Catling, D., Fryer, C., …Zahnle, K. (2018). Consequences of Giant Impacts on Early Uranus for Rotation, Internal Structure, Debris, and Atmospheric Erosion. Astrophysical Journal, 861(1), Article 52. https://doi.org/10.3847/1538-4357/aac725

We perform a suite of smoothed particle hydrodynamics simulations to investigate in detail the results of a giant impact on the young Uranus. We study the internal structure, rotation rate, and atmospheric retention of the post-impact planet, as well... Read More about Consequences of Giant Impacts on Early Uranus for Rotation, Internal Structure, Debris, and Atmospheric Erosion.

The diverse density profiles of galaxy clusters with self-interacting dark matter plus baryons (2018)
Journal Article
Robertson, A., Massey, R., Eke, V., Tulin, S., Yu, H., Bahé, Y., …Schaye, J. (2018). The diverse density profiles of galaxy clusters with self-interacting dark matter plus baryons. Monthly Notices of the Royal Astronomical Society: Letters, 476(1), L20-L24. https://doi.org/10.1093/mnrasl/sly024

We present the first simulated galaxy clusters (M200 > 1014 M⊙) with both self-interacting dark matter (SIDM) and baryonic physics. They exhibit a greater diversity in both dark matter and stellar density profiles than their counterparts in simulatio... Read More about The diverse density profiles of galaxy clusters with self-interacting dark matter plus baryons.

Evidence for a Localized Source of the Argon in the Lunar Exosphere (2017)
Journal Article
Kegerreis, J. A., Eke, V. R., Massey, R. J., Beaumont, S. K., Elphic, R. C., & Teodoro, L. F. (2017). Evidence for a Localized Source of the Argon in the Lunar Exosphere. Journal of Geophysical Research: Planets, 122(10), 2163-2181. https://doi.org/10.1002/2017je005352

We perform the first tests of various proposed explanations for observed features of the Moon's argon exosphere, including models of the following: spatially varying surface interactions; a source that reflects the lunar near-surface potassium distri... Read More about Evidence for a Localized Source of the Argon in the Lunar Exosphere.

Equatorial locations of water on Mars: Improved resolution maps based on Mars Odyssey Neutron Spectrometer data (2017)
Journal Article
Wilson, J. T., Eke, V. R., Massey, R. J., Elphic, R. C., Feldman, W. C., Maurice, S., & Teodoro, L. F. (2018). Equatorial locations of water on Mars: Improved resolution maps based on Mars Odyssey Neutron Spectrometer data. Icarus, 299, 148-160. https://doi.org/10.1016/j.icarus.2017.07.028

We present a map of the near subsurface hydrogen distribution on Mars, based on epithermal neutron data from the Mars Odyssey Neutron Spectrometer. The map’s spatial resolution is approximately improved two-fold via a new form of the pixon image reco... Read More about Equatorial locations of water on Mars: Improved resolution maps based on Mars Odyssey Neutron Spectrometer data.

Knowing the unknowns: uncertainties in simple estimators of galactic dynamical masses (2017)
Journal Article
Campbell, D. J., Frenk, C. S., Jenkins, A., Eke, V. R., Navarro, J. F., Sawala, T., …Theuns, T. (2017). Knowing the unknowns: uncertainties in simple estimators of galactic dynamical masses. Monthly Notices of the Royal Astronomical Society, 469(2), 2335-2360. https://doi.org/10.1093/mnras/stx975

The observed stellar kinematics of dispersion-supported galaxies are often used to measure dynamical masses. Recently, several analytical relationships between the stellar line-of-sight velocity dispersion, the projected (2D) or deprojected (3D) half... Read More about Knowing the unknowns: uncertainties in simple estimators of galactic dynamical masses.