Search Publications
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…
Observational constraints on the deceleration parameter in a tilted universe
Asvesta, Kerkyra; Kazantzidis, Lavrentios; Perivolaropoulos, Leandros +1 more
We study a parametrization of the deceleration parameter in a tilted universe, namely a cosmological model equipped with two families of observers. The first family follows the smooth Hubble flow, while the second is the real observers residing in a typical galaxy inside a bulk flow and moving relative to the smooth Hubble expansion with finite pe…
Constraining the original composition of the gas forming first-generation stars in globular clusters
Milone, A. P.; Cordoni, G.; Marino, A. F. +13 more
Disentangling distinct stellar populations along the red-giant branches (RGBs) of globular clusters (GCs) is possible by using the pseudo-two-colour diagram dubbed chromosome map (ChM). One of the most intriguing findings is that the so-called first-generation (1G) stars, characterized by the same chemical composition of their natal cloud, exhibit…
The GALAH survey: chemical clocks
Lewis, Geraint F.; Casey, Andrew R.; Buder, Sven +29 more
We present the first large-scale study that demonstrates how ages can be determined for large samples of stars through Galactic chemical evolution. Previous studies found that the elemental abundances of a star correlate directly with its age and metallicity. Using this knowledge, we derive ages for 214 577 stars in GALAH DR3 using only overall me…