Search Publications
The Pristine Inner Galaxy Survey (PIGS): IX. The largest detailed chemical analysis of very metal-poor stars in the Sagittarius dwarf galaxy
Sestito, Federico; Martin, Nicolas F.; Kordopatis, Georges +16 more
The most metal-poor stars provide valuable insights into the early chemical enrichment history of a system, carrying the chemical imprints of the first generations of supernovae. The most metal-poor region of the Sagittarius dwarf galaxy remains inadequately observed and characterised. To date, only ∼4 stars with [Fe/H] < ‑2.0 have been chemica…
Unveiling the internal structure and formation history of the three planets transiting HIP 29442 (TOI-469) with CHEOPS
Alonso, R.; Deleuil, M.; Erikson, A. +91 more
Multiplanetary systems spanning the radius valley are ideal testing grounds for exploring the different proposed explanations for the observed bimodality in the radius distribution of close-in exoplanets. One such system is HIP 29442 (TOI-469), an evolved K0V star hosting two super-Earths and one sub-Neptune. We observed HIP 29442 with CHEOPS for …
Dust and power: Unravelling the merger-active galactic nucleus connection in the second half of cosmic history
Wang, L.; Davé, R.; Yang, G. +8 more
Aims. Galaxy mergers represent a fundamental physical process under hierarchical structure formation, but their role in triggering active galactic nuclei (AGNs) is still unclear. We aim to investigate the merger-AGN connection using state-of-the-art observations and novel methods for detecting mergers and AGNs. Methods. We selected stellar mass-li…
Broadband X-ray/UV/optical time-resolved spectroscopy of NGC 5548: The origin of the UV/optical variability in active galactic nuclei
Papadakis, I. E.; Dovčiak, M.; Kammoun, E. +1 more
Context. Recently, nearby bright galaxies have been the subject of long monitoring surveys in the X-rays, UV, and optical. All of these campaigns revealed a strong correlation between the various UV and optical bands, with time lags that increase with wavelength. In a series of papers, we have demonstrated that a scenario in which an X-ray source …
Investigating episodic mass loss in evolved massive stars. I. Spectroscopy of dusty massive stars in ten southern galaxies
Zapartas, E.; de Wit, S.; Bonanos, A. Z. +7 more
Context. Episodic mass-loss events such as giant eruptions in luminous blue variables or pre-supernova eruptions in red supergiants drastically alter the evolutionary path of a massive star, resulting in a rich and complex circumstellar environment and IR excess. However, the incidence of these events, and hence their importance in massive star ev…
A 500 pc volume-limited sample of hot subluminous stars. I. Space density, scale height, and population properties
Geier, S.; Kepler, S. O.; Heber, U. +25 more
We present the first volume-limited sample of spectroscopically confirmed hot subluminous stars out to 500 pc, defined using the accurate parallax measurements from the Gaia space mission data release 3 (DR3). The sample comprises a total of 397 members, with 305 (~77%) identified as hot subdwarf stars, including 83 newly discovered systems. Of th…
TESS and ESPRESSO discover a super-Earth and a mini-Neptune orbiting the K-dwarf TOI-238*
Bouchy, F.; Rebolo, R.; Pallé, E. +53 more
The number of super-Earth and mini-Neptune planet discoveries has increased significantly in the last two decades thanks to transit and radial velocity (RV) surveys. When it is possible to apply both techniques, we can characterise the internal composition of exoplanets, which in turn provides unique insights on their architecture, formation and e…
The VISTA Variables in the Vía Láctea extended (VVVX) ESO public survey: Completion of the observations and legacy
Tamura, M.; Schultheis, M.; Minniti, D. +143 more
Context. The ESO public survey VISTA Variables in the Vía Láctea (VVV) surveyed the inner Galactic bulge and the adjacent southern Galactic disk from 2009–2015. Upon its conclusion, the complementary VVV extended (VVVX) survey has expanded both the temporal as well as spatial coverage of the original VVV area, widening it from 562 to 1700 sq. deg.…
Tracing the rise of supermassive black holes. A panchromatic search for faint, unobscured quasars at z ≳ 6 with COSMOS-Web and other surveys
Casey, Caitlin M.; Koekemoer, Anton M.; Wilkins, Stephen M. +20 more
We report the identification of 64 new candidates of compact galaxies, potentially hosting faint quasars with bolometric luminosities of Lbol = 1043-1046 erg s−1, residing in the reionization epoch within the redshift range of 6 ≲ z ≲ 8. These candidates were selected by harnessing the rich multiband dat…
PDRs4All: X. ALMA and JWST detection of neutral carbon in the externally irradiated disk d203-506: Undepleted gas-phase carbon
Le Bourlot, J.; Le Petit, F.; Roueff, E. +26 more
The gas-phase abundance of carbon, xC = [C/H]gas = xC+ + xC0 + xCO + … , and its depletion factors are essential parameters for understanding the gas and solid compositions that are ultimately incorporated into (exo)planets. The majority of protoplanetary disks are born i…