Search Publications
A ring in a shell: the large-scale 6D structure of the Vela OB2 complex
Jordi, C.; Cantat-Gaudin, T.; Balaguer-Núñez, L. +3 more
Context. The Vela OB2 association is a group of ∼10 Myr stars exhibiting a complex spatial and kinematic substructure. The all-sky Gaia DR2 catalogue contains proper motions, parallaxes (a proxy for distance), and photometry that allow us to separate the various components of Vela OB2.
Aims: We characterise the distribution of the Vela OB2 st…
Confirming Herschel Candidate Protoclusters from ALMA/VLA CO Observations
Pérez-Fournon, I.; Valtchanov, I.; Clements, D. L. +11 more
ALMA 870 µm continuum imaging has uncovered a population of blends of multiple dusty star-forming galaxies (DSFGs) in sources originally detected with the Herschel Space Observatory. However, their pairwise separations are much smaller than what is found by ALMA follow-up of other single-dish surveys or expected from theoretical simulations.…
Weighing the Darkness: Astrometric Mass Measurement of Hidden Stellar Companions Using Gaia
Breivik, Katelyn; Andrews, Jeff J.; Chatterjee, Sourav
In astrometric binaries, the presence of a dark, unseen star can be inferred from the gravitational pull it induces on its luminous binary companion. While the orbit of such binaries can be characterized with precise astrometric measurements, constraints made from astrometry alone are not enough to measure the component masses. In this work, we de…
Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event
Cenko, S. B.; Veilleux, S.; Foley, Ryan J. +25 more
We report the discovery of nonstellar hydrogen Balmer and metastable helium absorption lines accompanying a transient, high-velocity (0.05c) broad absorption line (BAL) system in the optical spectra of the tidal disruption event (TDE) AT2018zr (z = 0.071). In the Hubble Space Telescope UV spectra, absorption of high- and low-ionization lines is al…
The Gaia-ESO survey: Calibrating a relationship between age and the [C/N] abundance ratio with open clusters
Gilmore, G.; Bayo, A.; Prada Moroni, P. G. +51 more
Context. In the era of large high-resolution spectroscopic surveys such as Gaia-ESO and APOGEE, high-quality spectra can contribute to our understanding of the Galactic chemical evolution by providing abundances of elements that belong to the different nucleosynthesis channels, and also by providing constraints to one of the most elusive astrophys…
HD 1397b: A Transiting Warm Giant Planet Orbiting A V = 7.8 mag Subgiant Star Discovered by TESS
Henning, Thomas; Jordán, Andrés; Espinoza, Néstor +12 more
We report the discovery of a transiting planet first identified as a candidate in Sector 1 of the Transiting Exoplanet Survey Satellite (TESS), and then confirmed with precision radial velocities. HD 1397b has a mass of {M}{{P}} ={0.367}-0.023+0.022 {M}{{J}}, a radius of {R}{{P}}={1.023}-…
Constraining disk evolution prescriptions of planet population synthesis models with observed disk masses and accretion rates
Lodato, G.; Testi, L.; Williams, J. P. +4 more
While planets are commonly discovered around main-sequence stars, the processes leading to their formation are still far from being understood. Current planet population synthesis models, which aim to describe the planet formation process from the protoplanetary disk phase to the time exoplanets are observed, rely on prescriptions for the underlyi…
Solar Wind Implantation Into the Lunar Regolith: Monte Carlo Simulations of H Retention in a Surface With Defects and the H2 Exosphere
Farrell, W. M.; Killen, R. M.; Tucker, O. J. +1 more
The solar wind implants protons into the top 20-30 nm of lunar regolith grains, and the implanted hydrogen will diffuse out of the regolith but also interact with oxygen in the regolith oxides. We apply a statistical approach to estimate the diffusion of hydrogen in the regolith hindered by forming temporary bonds with regolith oxygen atoms. A Mon…
Chemical (in)homogeneity and atomic diffusion in the open cluster M 67
Yong, D.; Asplund, M.; Dotter, A. +4 more
Context. The benchmark open cluster M 67 is known to have solar metallicity and an age similar to that of the Sun. It thus provides us with a great opportunity to study the properties of solar twins, as well as the evolution of Sun-like stars.
Aims: Previous spectroscopic studies of M 67 reported possible subtle changes in stellar surface abu…
Slowing of the Solar Wind in the Outer Heliosphere
Stern, S. Alan; Weaver, Harold A.; Young, Leslie A. +15 more
This study provides a deeper understanding of how the solar wind evolves with increasing distance from the Sun as it encounters an increasing amount of interstellar material. This work extends our prior work by (1) extending the solar wind proton data radial profiles for New Horizons (NH) out to nearly 43 au, (2) quantifying the observed amount of…