Search Publications
Characterizing epochs of star formation across the Milky Way disc using age-metallicity distributions of GALAH stars
Feuillet, Diane K.; Feltzing, Sofia; Sahlholdt, Christian L.
We provide a detailed map of the ages and metallicities of turn-off stars in the Milky Way disc based on data from GALAH DR3 and Gaia EDR3. From this map, we identify previously undetected features in the age-metallicity distribution of disc stars and interpret these results as indicating a three-phase formation history of the Milky Way. In the fi…
Multiple phase spirals suggest multiple origins in Gaia DR3
Price-Whelan, Adrian M.; Johnston, Kathryn V.; Darragh-Ford, Elise +1 more
Gaia Data Release 2 revealed that the Milky Way contains significant indications of departures from equilibrium in the form of asymmetric features in the phase space density of stars in the Solar neighbourhood. One such feature is the z-vz phase spiral, interpreted as the response of the disc to the influence of a perturbation perpendic…
Photometry and astrometry with JWST - I. NIRCam point spread functions and the first JWST colour-magnitude diagrams of a globular cluster
Salaris, M.; Bedin, L. R.; Nardiello, D. +4 more
As the James Webb Space Telescope (JWST) has become fully operational, early release data are now available to begin building the tools and calibrations for precision point-source photometry and astrometry in crowded cluster environments. Here, we present our independent reduction of NIRCam imaging of the metal-poor globular cluster M 92, which we…
Accretion mode versus radio morphology in the LOFAR Deep Fields
Bondi, M.; Prandoni, I.; Shimwell, T. W. +17 more
Radio-loud active galaxies have two accretion modes [radiatively inefficient (RI) and radiatively efficient (RE)], with distinct optical and infrared signatures, and two jet dynamical behaviours, which in arcsec- to arcmin-resolution radio surveys manifest primarily as centre- or edge-brightened structures [Fanaroff-Riley (FR) class I and II]. The…
Automated galaxy-galaxy strong lens modelling: No lens left behind
Massey, Richard; Robertson, Andrew; Tam, Sut-Ieng +9 more
The distribution of dark and luminous matter can be mapped around galaxies that gravitationally lens background objects into arcs or Einstein rings. New surveys will soon observe hundreds of thousands of galaxy lenses and current labour-intensive analysis methods will not scale up to this challenge. We develop an automatic Bayesian method, which w…
One year of AU Mic with HARPS - I. Measuring the masses of the two transiting planets
Owen, James E.; Aigrain, Suzanne; Gandolfi, Davide +11 more
The system of two transiting Neptune-sized planets around the bright, young M-dwarf AU Mic provides a unique opportunity to test models of planet formation, early evolution, and star-planet interaction. However, the intense magnetic activity of the host star makes measuring the masses of the planets via the radial velocity (RV) method very challen…
The Galactic metallicity gradient shown by open clusters in the light of radial migration
Netopil, Martin; Oralhan, İnci Akkaya; Çakmak, Hikmet +2 more
During the last years and decades, several individual studies and large-scale spectroscopic surveys significantly improved our knowledge of the Galactic metallicity distribution based on open clusters. The availability of Gaia data provided a further step forward in our knowledge. However, still some open issues remain, for example, the influence …
Gradients of chemical abundances in the Milky Way from H II regions: distances derived from Gaia EDR3 parallaxes and temperature inhomogeneities
Méndez-Delgado, J. E.; Arellano-Córdova, K. Z.; García-Rojas, J. +4 more
We present a reassessment of the radial abundance gradients of He, C, N, O, Ne, S, Cl, and Ar in the Milky Way using the deep optical spectra of 42 H II regions presented in Arellano-Córdova et al. (2020, 2021) and Méndez-Delgado et al. (2020) exploring the impact of: (1) new distance determinations based on Gaia EDR3 parallaxes and (2) the use of…
The prevalence of galaxy overdensities around UV-luminous Lyman 𝛼 emitters in the Epoch of Reionization
Laporte, N.; Zitrin, A.; Oesch, P. A. +19 more
Before the end of the Epoch of Reionization, the Hydrogen in the Universe was predominantly neutral. This leads to a strong attenuation of Ly α lines of z ≳ 6 galaxies in the intergalactic medium. Nevertheless, Ly α has been detected up to very high redshifts (z ~ 9) for several especially UV luminous galaxies. Here, we test to what extent the gal…
The BAyesian STellar algorithm (BASTA): a fitting tool for stellar studies, asteroseismology, exoplanets, and Galactic archaeology
Christensen-Dalsgaard, J.; Weiss, A.; Serenelli, A. M. +16 more
We introduce the public version of the BAyesian STellar Algorithm (BASTA), an open-source code written in PYTHON to determine stellar properties based on a set of astrophysical observables. BASTA has been specifically designed to robustly combine large data sets that include asteroseismology, spectroscopy, photometry, and astrometry. We describe t…