Search Publications
Dark lens candidates from Gaia Data Release 3
Bennett, D. P.; Soszyński, I.; Udalski, A. +48 more
Gravitational microlensing is a phenomenon that allows us to observe the dark remnants of stellar evolution, even if these bodies are no longer emitting electromagnetic radiation. In particular, it can be useful to observe solitary neutron stars or stellar-mass black holes, providing a unique window through which to understand stellar evolution. O…
Detecting the edges of galaxies with deep learning
Buitrago, Fernando; Fernández-Iglesias, Jesús; Sahelices, Benjamín
Galaxy edges or truncations are low-surface-brightness (LSB) features located in the galaxy outskirts that delimit the distance up to where the gas density enables efficient star formation. As such, they could be interpreted as a non-arbitrary means to determine the galaxy size and this is also reinforced by the smaller scatter in the galaxy mass-…
A lack of Lyman α emitters within 5 Mpc of a luminous quasar in an overdensity at z = 6.9: Potential evidence of negative quasar feedback at protocluster scales
Hu, W.; Infante, L.; Wold, I. G. B. +13 more
High-redshift quasars are thought to live in the densest regions of space, which should be made evident by an overdensity of galaxies around them. However, campaigns to identify these overdensities by searching for Lyman-break galaxies (LBGs) and Lyman α emitters (LAEs) have had mixed results. These may be explained by either the small field of vi…
Exploring the hardness of the ionising radiation with the infrared softness diagram. I. Similar effective temperature scales for starbursts and (ultra)luminous infrared galaxies
Amorín, R.; Pérez-Montero, E.; Vílchez, J. M. +3 more
Aims: We explored the softness parameter in the infrared, ηIR', whose main purpose is the characterisation of the hardness of the incident ionising radiation in emission-line nebulae. This parameter is obtained from the combination of mid-infrared wavelength range transitions corresponding to consecutive ionisation stage…
PICZL: Image-based photometric redshifts for AGN
Shirley, R.; Bauer, F. E.; Salvato, M. +14 more
Context. Computing reliable photometric redshifts (photo-z) for active galactic nuclei (AGN) is a challenging task, primarily due to the complex interplay between the unresolved relative emissions associated with the supermassive black hole and its host galaxy. Spectral energy distribution (SED) fitting methods, while effective for galaxies and AG…
"Forbidden" stars in the eROSITA all-sky survey: X-ray emission from very late-type giants
Schmitt, J. H. M. M.; Czesla, S.; Robrade, J. +4 more
We present the results of the first X-ray all-sky survey (eRASS1) performed by the eROSITA instrument aboard the Spectrum-Roentgen-Gamma (SRG) mission on X-ray emitting red giants and supergiants. Focusing on stars positioned at high galactic latitudes above 20°, we constructed a complete sample of such objects using the Gaia DR3 catalog and ident…
Full orbital solutions in pre-main sequence high-order multiple systems: GG Tau Ab and UX Tau B
Duchêne, Gaspard; Ménard, François; Langlois, Maud +3 more
Context. High-order multiple (triple and beyond) systems are relatively common. Their interaction with circumstellar and circumbinary material can have a large impact on the formation and evolution of planetary systems and depends on their orbital properties.
Aims: GG Tau and UX Tau are two pre-main sequence high-order multiple systems in whi…
Peering above the clouds of the warm Neptune GJ 436 b with CRIRES+
Gandhi, Siddharth; Snellen, Ignas A. G.; Grasser, Natalie +2 more
Context. Exoplanets with masses between Earth and Neptune are amongst the most commonly observed, yet their properties are poorly constrained. Their transmission spectra are often featureless, which indicate either high-altitude clouds or a high atmospheric metallicity. The archetypical warm Neptune GJ 436 b is such a planet showing a flat transmi…
HdC and EHe stars through the prism of Gaia DR3. Evolution of RV amplitude and dust formation rate with effective temperature
Tisserand, P.; Crawford, C. L.; Clayton, G. C. +3 more
Context. The Gaia DR3 release includes heliocentric radial velocity measurements and velocity variability indices for tens of millions of stars observed over 34 months.
Aims: In this study, we utilise these indices to investigate the intrinsic radial velocity variations of Hydrogen-deficient Carbon (HdC) stars and Extreme Helium (EHe) stars a…
Transverse clues on the kiloparsec-scale structure of the circumgalactic medium as traced by C IV absorption
Bayliss, M. B.; Lopez, S.; Tejos, N. +13 more
The kiloparsec-scale kinematics and density structure of the circumgalactic medium (CGM) is still poorly constrained observationally, which poses a problem for understanding the role of the baryon cycle in galaxy evolution. Here we present VLT/MUSE integral-field spectroscopy (R ≈ 1800) of four giant gravitational arcs exhibiting W0 ≳ 0…