Search Publications

Lithium-rotation connection in the newly discovered young stellar stream Psc-Eri (Meingast 1)
DOI: 10.1051/0004-6361/201937137 Bibcode: 2020A&A...635L..13A

Bayo, A.; Bouy, H.; Bouvier, J. +4 more

Context. As a fragile element, lithium is a sensitive probe of physical processes occurring in stellar interiors.
Aims: We aim to investigate the relationship between lithium abundance and rotation rate in low-mass members of the newly discovered 125 Myr-old Psc-Eri stellar stream.
Methods: We obtained high-resolution optical spectra and…

2020 Astronomy and Astrophysics
Gaia 16
Foreshock Bubbles at Venus: Hybrid Simulations and VEX Observations
DOI: 10.1029/2019JA027056 Bibcode: 2020JGRA..12527056O

Omidi, N.; Collinson, G.; Sibeck, D.

In the absence of a global magnetic field at Venus, its ionosphere is the obstacle to the flow of the solar wind resulting in the formation of a smaller bow shock and foreshock. Spacecraft observations and global hybrid (kinetic ions, fluid electrons) simulations have demonstrated that despite its smaller size, the foreshock at Venus has propertie…

2020 Journal of Geophysical Research (Space Physics)
VenusExpress 16
New empirical constraints on the cosmological evolution of gas and stars in galaxies
DOI: 10.1093/mnras/staa1565 Bibcode: 2020MNRAS.496.1124P

Loeb, Abraham; Padmanabhan, Hamsa

We combine the latest observationally motivated constraints on stellar properties in dark matter haloes, along with data-driven predictions for the atomic (H I) and molecular (H2) gas evolution in galaxies, to derive empirical relationships between the build-up of galactic components and their evolution over cosmic time. At high redshif…

2020 Monthly Notices of the Royal Astronomical Society
eHST 16
Embedding globular clusters in dark matter minihaloes solves the cusp-core and timing problems in the Fornax dwarf galaxy
DOI: 10.1093/mnras/staa011 Bibcode: 2020MNRAS.492.3169B

Silk, Joseph; Boldrini, Pierre; Mohayaee, Roya

We use a fully GPU N-body code to demonstrate that dark matter (DM) minihaloes, as a new component of globular clusters (GCs), resolve both the timing and cusp-core problems in Fornax if the (five or six) GCs were recently accreted (≤3 Gyr ago) by Fornax. Under these assumptions, infall of these GCs does not occur and no star clusters form in the …

2020 Monthly Notices of the Royal Astronomical Society
Gaia 16
Formation and Evolution of the Large-Scale Magnetic Fields in Venus' Ionosphere: Results From a Three Dimensional Global Multispecies MHD Model
DOI: 10.1029/2020GL087593 Bibcode: 2020GeoRL..4787593M

Luhmann, Janet; Toth, Gabor; Nagy, Andrew +2 more

Large-scale magnetic fields have been observed in Venus' ionosphere by both the Pioneer Venus Orbiter (PVO) and Venus Express spacecraft. In this study, we examine the formation and evolution of the large-scale magnetic field in the Venus ionosphere using a sophisticated global multispecies Magnetohydrodynamics (MHD) model that has been developed …

2020 Geophysical Research Letters
VenusExpress 16
The Blanco DECam bulge survey. I. The survey description and early results
DOI: 10.1093/mnras/staa2426 Bibcode: 2020MNRAS.499.2340R

Clarkson, William I.; Robin, Annie C.; Martin, Nicolas +18 more

The Blanco Dark Energy Camera (DECam) Bulge survey is a Vera Rubin Observatory (LSST) pathfinder imaging survey, spanning ~200 deg2 of the Southern Galactic bulge, -2° < b < -13° and -11° < l < +11°. We have employed the CTIO-4 m telescope and the DECam to image a contiguous ~200 deg2 region of the relatively less…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 16
Propagation of waves above a plage as observed by IRIS and SDO
DOI: 10.1051/0004-6361/201936070 Bibcode: 2020A&A...634A..63K

Srivastava, A. K.; Mathioudakis, M.; Jelínek, P. +2 more

Context. Magnetohydrodynamic waves are proposed as the mechanism that transport sufficient energy from the photosphere to heat the transition region (TR) and corona. However, various aspects of these waves, such as their nature, propagation characteristics, and role in the atmospheric heating process, remain poorly understood and require further i…

2020 Astronomy and Astrophysics
IRIS 16
H0LiCOW - XI. A weak lensing measurement of the external convergence in the field of the lensed quasar B1608+656 using HST and Subaru deep imaging
DOI: 10.1093/mnras/staa1436 Bibcode: 2020MNRAS.498.1406T

Treu, T.; Fassnacht, C. D.; Meylan, G. +11 more

We investigate the environment and line of sight (LoS) of the H0LiCOW (H0 Lenses in COSMOGRAIL's Wellspring) lens B1608+656 using Subaru Suprime-Cam and the Hubble Space Telescope (HST) to perform a weak lensing analysis. We compare three different methods to reconstruct the mass map of the field, i.e. the standard Kaiser-Squires invers…

2020 Monthly Notices of the Royal Astronomical Society
eHST 16
Modelling the AGN broad-line region using single-epoch spectra - II. Nearby AGNs
DOI: 10.1093/mnras/staa285 Bibcode: 2020MNRAS.493.1227R

Treu, T.; Vestergaard, M.; Peterson, B. M. +4 more

The structure of the broad-line region (BLR) is an essential ingredient in the determination of active galactic nucleus (AGN) virial black hole masses, which in turn are important to study the role of black holes in galaxy evolution. Constraints on the BLR geometry and dynamics can be obtained from velocity-resolved studies using reverberation map…

2020 Monthly Notices of the Royal Astronomical Society
eHST 16
Prospects for measuring Mercury's tidal Love number h2 with the BepiColombo Laser Altimeter
DOI: 10.1051/0004-6361/201936517 Bibcode: 2020A&A...633A..85T

Oberst, J.; Iess, L.; Kallenbach, R. +7 more

Context. The Love number h2 describes the radial tidal displacements of Mercury's surface and allows constraints to be set on the inner core size when combined with the potential Love number k2. Knowledge of Mercury's inner core size is fundamental to gaining insights into the planet's thermal evolution and dynamo working pri…

2020 Astronomy and Astrophysics
BepiColombo 16