Search Publications
The GALAH survey and Gaia DR2: dissecting the stellar disc's phase space by age, action, chemistry, and location
Lewis, Geraint F.; Ting, Yuan-Sen; Casey, Andrew R. +24 more
We use the second data releases of the European Space AgencyGaia astrometric survey and the high-resolution Galactic Archaeology with HERMES (GALAH) spectroscopic survey to analyse the structure of our Galaxy's disc components. With GALAH, we separate the α-rich and α-poor discs (with respect to Fe), which are superposed in both position and veloc…
Deep learning of multi-element abundances from high-resolution spectroscopic data
Bovy, Jo; Leung, Henry W.
Deep learning with artificial neural networks is increasingly gaining attention because of its potential for data-driven astronomy. However, this methodology usually does not provide uncertainties and does not deal with incompleteness and noise in the training data. In this work, we design a neural network for high-resolution spectroscopic analysi…
Dynamical heating across the Milky Way disc using APOGEE and Gaia
Bovy, Jo; Chaplin, William J.; Cunha, Katia +14 more
The kinematics of the Milky Way disc as a function of age are well measured at the solar radius, but have not been studied over a wider range of Galactocentric radii. Here, we measure the kinematics of mono-age, mono-[Fe/H] populations in the low and high [α/Fe] discs between 4 ≲ R ≲ 13 kpc and |z| ≲ 2 kpc using 65 719 stars in common between APOG…
The Ophiuchus DIsc Survey Employing ALMA (ODISEA) - I: project description and continuum images at 28 au resolution
Ansdell, Megan; Gonzalez-Ruilova, Camilo; Cieza, Lucas A. +20 more
We introduce the Ophiuchus DIsc Survey Employing ALMA (ODISEA), a project aiming to study the entire population of Spitzer-selected protoplanetary discs in the Ophiuchus Molecular Cloud (∼300 objects) from both millimetre continuum and CO isotopologues data. Here we present 1.3 mm/230 GHz continuum images of 147 targets at 0.2 arcsec (28 au) resol…
A SHARP view of H0LiCOW: H0 from three time-delay gravitational lens systems with adaptive optics imaging
Treu, Tommaso; Sonnenfeld, Alessandro; Lagattuta, David J. +20 more
We present the measurement of the Hubble constant, H0, with three strong gravitational lens systems. We describe a blind analysis of both PG 1115+080 and HE 0435-1223 as well as an extension of our previous analysis of RXJ 1131-1231. For each lens, we combine new adaptive optics (AO) imaging from the Keck Telescope, obtained as part of …
Life in the fast lane: a direct view of the dynamics, formation, and evolution of the Milky Way's bar
Bovy, Jo; Mackereth, J. Ted; Hunt, Jason A. S. +3 more
Studies of the ages, abundances, and motions of individual stars in the Milky Way provide one of the best ways to study the evolution of disc galaxies over cosmic time. The formation of the Milky Way's barred inner region in particular is a crucial piece of the puzzle of disc galaxy evolution. Using data from APOGEE and Gaia, we present maps of th…
H2O abundances and cloud properties in ten hot giant exoplanets
Madhusudhan, Nikku; Gandhi, Siddharth; Pinhas, Arazi +1 more
Transmission spectroscopy of exoplanets has the potential to provide precise measurements of atmospheric chemical abundances, in particular of hot Jupiters whose large sizes and high temperatures make them conducive to such observations. To date, several transmission spectra of hot Jupiters have revealed low amplitude features of water vapour comp…
The hidden giant: discovery of an enormous Galactic dwarf satellite in Gaia DR2
Kuehn, K.; Li, T. S.; Evans, N. W. +8 more
We report the discovery of a Milky Way satellite in the constellation of Antlia. The Antlia 2 dwarf galaxy is located behind the Galactic disc at a latitude of b ∼ 11° and spans 1.26°, which corresponds to ∼2.9 kpc at its distance of 130 kpc. While similar in spatial extent to the Large Magellanic Cloud, Antlia 2 is orders of magnitude fainter at …
Constraining the thermally pulsing asymptotic giant branch phase with resolved stellar populations in the Small Magellanic Cloud
Boyer, Martha L.; Girardi, Léo; Dalcanton, Julianne J. +17 more
The thermally pulsing asymptotic giant branch (TP-AGB) experienced by low- and intermediate-mass stars is one of the most uncertain phases of stellar evolution and the models need to be calibrated with the aid of observations. To this purpose, we couple high-quality observations of resolved stars in the Small Magellanic Cloud (SMC) with detailed s…
The Southern Photometric Local Universe Survey (S-PLUS): improved SEDs, morphologies, and redshifts with 12 optical filters
Riguccini, L.; Molino, A.; Pereira, C. B. +142 more
The Southern Photometric Local Universe Survey (S-PLUS) is imaging ∼9300 deg2 of the celestial sphere in 12 optical bands using a dedicated 0.8 m robotic telescope, the T80-South, at the Cerro Tololo Inter-american Observatory, Chile. The telescope is equipped with a 9.2k × 9.2k e2v detector with 10 {µ m} pixels, resulting in a fi…