Search Publications
Dual MeV gamma-ray and dark matter observatory - GRAMS Project
Odaka, Hirokazu; Aramaki, Tsuguo; Karagiorgi, Georgia +1 more
GRAMS (Gamma-Ray and AntiMatter Survey) is a novel project that can simultaneously target both astrophysical observations with MeV gamma rays and an indirect dark matter search with antimatter. The GRAMS instrument is designed with a cost-effective, large-scale LArTPC (Liquid Argon Time Projection Chamber) detector surrounded by plastic scintillat…
Ubiquitous velocity fluctuations throughout the molecular interstellar medium
Henning, Thomas; Henshaw, Jonathan D.; Kruijssen, J. M. Diederik +23 more
The density structure of the interstellar medium determines where stars form and release energy, momentum and heavy elements, driving galaxy evolution1-4. Density variations are seeded and amplified by gas motion, but the exact nature of this motion is unknown across spatial scales and galactic environments5. Although dense s…
Reflex motion in the Milky Way stellar halo resulting from the Large Magellanic Cloud infall
Peñarrubia, Jorge; Petersen, Michael S.
We present the results of N-body models of the Milky Way and Large Magellanic Cloud system and study the kinematic reflex motion in the stellar halo owing to the barycentre displacement of the disc. In agreement with previous studies, we find that the Milky Way disc may be moving at 40 km~s^{-1} relative to the barycentre prior to the Large Magell…
The Gaia-ESO survey: the non-universality of the age-chemical-clocks-metallicity relations in the Galactic disc
Baratella, M.; Gilmore, G.; Bayo, A. +36 more
Context. In the era of large spectroscopic surveys, massive databases of high-quality spectra coupled with the products of the Gaia satellite provide tools to outline a new picture of our Galaxy. In this framework, an important piece of information is provided by our ability to infer stellar ages, and consequently to sketch a Galactic timeline.
Globular clusters in Coma cluster ultra-diffuse galaxies (UDGs): evidence for two types of UDG?
Forbes, Duncan A.; Romanowsky, Aaron J.; Brodie, Jean P. +2 more
Ultra-diffuse galaxies (UDGs) reveal extreme properties. Here, we compile the largest study to date of 85 globular cluster (GC) systems around UDGs in the Coma cluster, using new deep ground-based imaging of the known UDGs and existing imaging from the Hubble Space Telescope of their GC systems. We find that the richness of GC systems in UDGs gene…
Project AMIGA: The Circumgalactic Medium of Andromeda
Brown, Thomas M.; Faucher-Giguère, Claude-André; Hafen, Zachary +22 more
Project AMIGA (Absorption Maps In the Gas of Andromeda) is a survey of the circumgalactic medium (CGM) of Andromeda (M31, ${R}_{\mathrm{vir}}$ ≃ 300 kpc) along 43 QSO sightlines at impact parameters 25 ≤ R ≤ 569 kpc (25 at R ≲ ${R}_{\mathrm{vir}}$). We use ultraviolet absorption measurements of Si II, Si III, Si IV, C II, and C IV from the Hubble …
2.5D retrieval of atmospheric properties from exoplanet phase curves: application to WASP-43b observations
Irwin, Patrick G. J.; Aigrain, Suzanne; Parmentier, Vivien +4 more
We present a novel retrieval technique that attempts to model phase curve observations of exoplanets more realistically and reliably, which we call the 2.5-dimensional (2.5D) approach. In our 2.5D approach we retrieve the vertical temperature profile and mean gaseous abundance of a planet at all longitudes and latitudes simultaneously, assuming th…
A measurement of water vapour amid a largely quiescent environment on Europa
Villanueva, G. L.; Roth, L.; Paganini, L. +4 more
Previous investigations proved the existence of local density enhancements in Europa's atmosphere, advancing the idea of a possible origination from water plumes. These measurement strategies, however, were sensitive either to total absorption or atomic emissions, which limited the ability to assess the water content. Here we present direct search…
Stellar clustering shapes the architecture of planetary systems
Kruijssen, J. M. Diederik; Longmore, Steven N.; Chevance, Mélanie +1 more
Planet formation is generally described in terms of a system containing the host star and a protoplanetary disk1-3, of which the internal properties (for example, mass and metallicity) determine the properties of the resulting planetary system4. However, (proto)planetary systems are predicted5,6 and observed7,…
The R-Process Alliance: First Magellan/MIKE Release from the Southern Search for R-process-enhanced Stars
Beers, Timothy C.; Placco, Vinicius M.; Hansen, Terese T. +9 more
Extensive progress has recently been made in our understanding of heavy-element production via the r-process in the universe, specifically with the first observed neutron star binary merger (NSBM) event associated with the gravitational-wave signal detected by LIGO, GW170817. The chemical abundance patterns of metal-poor r-process-enhanced stars p…