Search Publications
Age-resolved chemistry of red giants in the solar neighbourhood
Bovy, Jo; Majewski, Steven R.; Feuillet, Diane K. +7 more
In the age of high-resolution spectroscopic stellar surveys of the Milky Way, the number of stars with detailed abundances of multiple elements is rapidly increasing. These elemental abundances are directly influenced by the evolutionary history of the Galaxy, but this can be difficult to interpret without an absolute timeline of the abundance enr…
SN 2017ein and the Possible First Identification of a Type Ic Supernova Progenitor
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Kelly, Patrick L. +11 more
We have identified a progenitor candidate in archival Hubble Space Telescope (HST) images for the Type Ic supernova (SN Ic) SN 2017ein in NGC 3938, pinpointing the candidate’s location via HST Target of Opportunity imaging of the SN itself. This would be the first identification of a stellar-like object as a progenitor candidate for any SN Ic to d…
Different Stellar Rotations in the Two Main Sequences of the Young Globular Cluster NGC 1818: The First Direct Spectroscopic Evidence
Milone, A. P.; Marino, A. F.; D'Antona, F. +4 more
We present a spectroscopic analysis of main sequence (MS) stars in the young globular cluster NGC 1818 (age ∼40 Myr) in the Large Magellanic Cloud. Our photometric survey of Magellanic Clouds clusters has revealed that NGC 1818, similar to other young objects with ages ≲600 Myr, displays not only an extended MS turnoff (eMSTO), as observed in inte…
The Gaia-ESO Survey: open clusters in Gaia-DR1 . A way forward to stellar age calibration
Gilmore, G.; Bayo, A.; Bouy, H. +42 more
Context. Determination and calibration of the ages of stars, which heavily rely on stellar evolutionary models, are very challenging, while representing a crucial aspect in many astrophysical areas.
Aims: We describe the methodologies that, taking advantage of Gaia-DR1 and the Gaia-ESO Survey data, enable the comparison of observed open star …
LLAMA: normal star formation efficiencies of molecular gas in the centres of luminous Seyfert galaxies
Lutz, D.; Genzel, R.; Sturm, E. +23 more
Using new Atacama Pathfinder Experiment and James Clerk Maxwell Telescope spectroscopy of the CO 2→1 line, we undertake a controlled study of cold molecular gas in moderately luminous (Lbol = 1043-44.5 erg s-1) active galactic nuclei (AGN) and inactive galaxies from the Luminous Local AGN with Matched Analogs (LLAM…
The Black Hole in the Most Massive Ultracompact Dwarf Galaxy M59-UCD3
Romanowsky, Aaron J.; Pechetti, Renuka; Krajnović, Davor +19 more
We examine the internal properties of the most massive ultracompact dwarf galaxy (UCD), M59-UCD3, by combining adaptive-optics-assisted near-IR integral field spectroscopy from Gemini/NIFS and Hubble Space Telescope (HST) imaging. We use the multiband HST imaging to create a mass model that suggests and accounts for the presence of multiple stella…
ExoGAN: Retrieving Exoplanetary Atmospheres Using Deep Convolutional Generative Adversarial Networks
Zingales, Tiziano; Waldmann, Ingo P.
Atmospheric retrievals on exoplanets usually involve computationally intensive Bayesian sampling methods. Large parameter spaces and increasingly complex atmospheric models create a computational bottleneck forcing a trade-off between statistical sampling accuracy and model complexity. It is especially true for upcoming JWST and ARIEL observations…
A single population of red globular clusters around the massive compact galaxy NGC 1277
Beasley, Michael A.; Leaman, Ryan; Trujillo, Ignacio +1 more
Massive galaxies are thought to form in two phases: an initial collapse of gas and giant burst of central star formation, followed by the later accretion of material that builds up their stellar and dark-matter haloes. The systems of globular clusters within such galaxies are believed to form in a similar manner. The initial central burst forms me…
Electron Acceleration by Dipolarization Fronts and Magnetic Reconnection: A Quantitative Comparison
Xu, Y.; Fu, H. S.; Liu, C. M. +1 more
Suprathermal electrons with energy from tens to hundreds of keV are frequently observed in the Earth's magnetotail. The generation of such electrons is typically attributed to magnetic reconnection, dipolarization fronts (DFs), or flux transport. However, which of these contributes more to this generation remains unclear. In this study, we quantit…
Modelling the Tucana III stream - a close passage with the LMC
Bechtol, K.; Smith, M.; D'Andrea, C. B. +67 more
We present results of the first dynamical stream fits to the recently discovered Tucana III stream. These fits assume a fixed Milky Way potential and give proper motion predictions, which can be tested with the upcoming Gaia Data Release 2 (DR2). These fits reveal that Tucana III is on an eccentric orbit around the Milky Way and, more interestingl…