Search Publications
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…
The updated BASTI stellar evolution models and isochrones - III. White dwarfs
Salaris, Maurizio; Cassisi, Santi; Pietrinferni, Adriano +1 more
We present new cooling models for carbon-oxygen white dwarfs (WDs) with both H- and He-atmospheres, covering the whole relevant mass range, to extend our updated BASTI (a Bag of Stellar Tracks and Isochrones) stellar evolution archive. They have been computed using core chemical stratifications obtained from new progenitor calculations, adopting a…
The Gaia-ESO Survey: Membership probabilities for stars in 63 open and 7 globular clusters from 3D kinematics
Gilmore, G.; Montes, D.; Prada Moroni, P. G. +26 more
Spectroscopy from the final internal data release of the Gaia-ESO Survey (GES) has been combined with Gaia EDR3 to assign membership probabilities to targets observed towards 63 Galactic open clusters and 7 globular clusters. The membership probabilities are based chiefly on maximum likelihood modelling of the 3D kinematics of the targets, separat…
TESS asteroseismology of the Kepler red giants
Huber, Daniel; García, Rafael A.; Saunders, Nicholas +11 more
Red giant asteroseismology can provide valuable information for studying the Galaxy as demonstrated by space missions like CoRoT and Kepler. However, previous observations have been limited to small data sets and fields of view. The TESS mission provides far larger samples and, for the first time, the opportunity to perform asteroseimic inference …
The VANDELS survey: a measurement of the average Lyman-continuum escape fraction of star-forming galaxies at z = 3.5
Schaerer, D.; Cullen, F.; McLure, R. J. +20 more
We present a study designed to measure the average Lyman-continuum escape fraction (⟨fesc⟩) of star-forming galaxies at z ≃ 3.5. We assemble a sample of 148 galaxies from the VANDELS spectroscopic survey at 3.35 ≤ zspec ≤ 3.95, selected to minimize line-of-sight contamination of their photometry. For this sample, we use ultra…
Abundant ammonium hydrosulphide embedded in cometary dust grains
Altwegg, K.; Fuselier, S. A.; Rubin, M. +7 more
Ammonium hydrosulphide has long since been postulated to exist at least in certain layers of the giant planets. Its radiation products may be the reason for the red colour seen on Jupiter. Several ammonium salts, the products of NH3, and an acid have previously been detected at comet 67P/Churyumov-Gerasimenko. The acid H2S is…
Polarization constraints on the X-ray corona in Seyfert Galaxies: MCG-05-23-16
Antonelli, L. A.; Costa, E.; Bianchi, S. +97 more
We report on the first observation of a radio-quiet active galactic nucleus (AGN) in polarized X-rays: the Seyfert 1.9 galaxy MCG-05-23-16. This source was pointed at with the Imaging X-ray Polarimetry Explorer (IXPE) starting on 2022 May 14 for a net observing time of 486 ks, simultaneously with XMM-Newton (58 ks) and NuSTAR (83 ks). A polarizati…
Merger-induced galaxy transformations in the ARTEMIS simulations
Belokurov, Vasily; Dillamore, Adam M.; McCarthy, Ian G. +1 more
Using the ARTEMIS set of 45 high-resolution cosmological simulations, we investigate a range of merger-induced dynamical transformations of Milky Way-like galaxies. We first identify populations of accreted stars on highly radial orbits, similar to the 'Gaia Sausage' in the Milky Way. We show that ≈1/3 of the ARTEMIS galaxies contain a similar fea…