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X-Shooting ULLYSES: Massive stars at low metallicity. I. Project description
Bouret, J. -C.; Martins, F.; van Loon, J. Th. +78 more
Observations of individual massive stars, super-luminous supernovae, gamma-ray bursts, and gravitational wave events involving spectacular black hole mergers indicate that the low-metallicity Universe is fundamentally different from our own Galaxy. Many transient phenomena will remain enigmatic until we achieve a firm understanding of the physics …
The star formation history of the Sco-Cen association. Coherent star formation patterns in space and time
Meingast, Stefan; Alves, João; Rottensteiner, Alena +13 more
We reconstructed the star formation history of the Sco-Cen OB association using a novel high-resolution age map of the region. We developed an approach to produce robust ages for Sco-Cen's recently identified 37 stellar clusters using the SigMA algorithm. The Sco-Cen star formation timeline reveals four periods of enhanced star formation activity,…
AF Lep b: The lowest-mass planet detected by coupling astrometric and direct imaging data
Kervella, P.; D'Orazi, V.; Zurlo, A. +6 more
Aims: Using the direct-imaging technique, we searched for low-mass companions around the star AF Lep, which presents a significant proper-motion anomaly (PMa) signal obtained from the comparison of HIPPARCOS and Gaia eDR3 catalogs.
Methods: We observed AF Lep in two epochs with VLT/SPHERE using its subsystems IFS and IRDIS in the near-in…
Gaia Data Release 3. Gaia scan-angle-dependent signals and spurious periods
Harrison, D. L.; Audard, M.; Gosset, E. +23 more
Context. Gaia Data Release 3 (Gaia DR3) time series data may contain spurious signals related to the time-dependent scan angle.
Aims: We aim to explain the origin of scan-angle-dependent signals and how they can lead to spurious periods, provide statistics to identify them in the data, and suggest how to deal with them in Gaia DR3 data and in…
Detection of the Keplerian decline in the Milky Way rotation curve
Amram, Philippe; Chemin, Laurent; Hammer, François +4 more
Our position inside the Galactic disc has previously prevented us from establishing an accurate rotation curve (RC). The advent of Gaia and its third data release (Gaia DR3) made it possible to specify the RC up to twice the optical radius. We aim to establish a new RC of the Galaxy from the Gaia DR3 by drastically reducing systematic uncertaintie…
Stellar ages, masses, extinctions, and orbital parameters based on spectroscopic parameters of Gaia DR3
Schultheis, M.; Recio-Blanco, A.; de Laverny, P. +13 more
Context.Gaia's third data release provides radial velocities for 33 million stars and spectroscopically derived atmospheric parameters for more than 5 million targets. When combined with the astrometric data, these allow us to derive orbital and stellar parameters that are key to understanding the stellar populations of the Milky Way and to perfor…
XRBcats: Galactic low-mass X-ray binary catalogue
Santangelo, A.; Wilms, J.; Doroshenko, V. +3 more
We present a new catalogue of low-mass X-ray binaries (LMXBs) in the Galaxy. The catalogue contains source names, coordinates, source types, fluxes, distances, system parameters, and other characteristic properties of 349 LMXBs, including systems that have been newly discovered or reclassified since the most recently reported LMXB catalogues. The …
Spectroscopic age estimates for APOGEE red-giant stars: Precise spatial and kinematic trends with age in the Galactic disc
Schultheis, M.; Casamiquela, L.; Anders, F. +12 more
Over the last few years, many studies have found an empirical relationship between the abundance of a star and its age. Here we estimate spectroscopic stellar ages for 178 825 red-giant stars observed by the APOGEE survey with a median statistical uncertainty of 17%. To this end, we use the supervised machine learning technique XGBoost, trained on…
XRBcats: Galactic High Mass X-ray Binary Catalogue★
Santangelo, A.; Doroshenko, V.; Avakyan, A. +1 more
Context. We present a new catalogue of high mass X-ray binaries (HMXBs) in the Galaxy that we call the Galactic High Mass X-ray Binary Catalogue (XRBcats), which improves upon the most recent of such catalogues. We include new HMXBs discovered since previous publications and revise the classification for several objects previously considered HMXBs…
Alive and kicking: A new QPE phase in GSN 069 revealing a quiescent luminosity threshold for QPEs
Read, A. M.; Miniutti, G.; Kara, E. +4 more
X-ray quasi-periodic eruptions (QPEs) are intense repeating soft X-ray bursts from the nuclei of nearby galaxies. Their physical origin is still largely unconstrained, and several theoretical models have been proposed ranging from disc instabilities to impacts between an orbiting companion and the existing accretion disc around the primary, or epi…