Search Publications
The IACOB project. VIII. Searching for empirical signatures of binarity in fast-rotating O-type stars
Herrero, A.; Simón-Díaz, S.; Nazé, Y. +6 more
Context. The empirical distribution of projected rotational velocities (v sin i) in massive O-type stars is characterised by a dominant slow velocity component and a tail of fast rotators. It has been proposed that binary interaction plays a dominant role in the formation of this tail.
Aims: We perform a complete and homogeneous search for em…
A hidden population of white dwarfs with atmospheric carbon traces in the Gaia bifurcation
Rebassa-Mansergas, Alberto; Hollands, Mark; Althaus, Leandro G. +4 more
Context. The high-quality photometric and astrometric capabilities of the ESA Gaia space mission have revealed a bifurcation of the white dwarf sequence on the color magnitude diagram with two branches: A and B. While the A branch consists mostly of white dwarfs with hydrogen(H)-rich atmospheres, the B branch is not completely understood. Although…
TOI-5678b: A 48-day transiting Neptune-mass planet characterized with CHEOPS and HARPS★
Alonso, R.; Bouchy, F.; Deleuil, M. +92 more
Context. A large sample of long-period giant planets has been discovered thanks to long-term radial velocity surveys, but only a few dozen of these planets have a precise radius measurement. Transiting gas giants are crucial targets for the study of atmospheric composition across a wide range of equilibrium temperatures and, more importantly, for …
X-SHYNE: X-shooter spectra of young exoplanet analogs. I. A medium-resolution 0.65-2.5 µm one-shot spectrum of VHS 1256−1257 b
Bayo, A.; Tremblin, P.; Lagrange, A. -M. +13 more
We present simultaneous 0.65-2.5 µm medium resolution (3300 ≤ Rλ ≤ 8100) VLT/X-shooter spectra of the relatively young (150-300 Myr) low-mass (19 ± 5MJup) L-T transition object VHS 1256−1257 b, a known spectroscopic analog of HR8799d. The companion is a prime target for the JWST Early Release Science (ERS) and one of th…
Oxygen, sulfur, and iron radial abundance gradients of classical Cepheids across the Galactic thin disk★★★
Kovtyukh, V.; Lemasle, B.; Fabrizio, M. +25 more
Context. Classical Cepheids (CCs) are solid distance indicators and tracers of young stellar populations. Dating back to the beginning of the 20th century, they have been safely adopted to trace the rotation, kinematics, and chemical enrichment history of the Galactic thin disk.
Aims: The main aim of this investigation is to provide iron, oxy…
Discovery of the luminous X-ray ignition eRASSt J234402.9−352640. I. Tidal disruption event or a rapid increase in accretion in an active galactic nucleus?
Gromadzki, M.; Liu, Z.; Rau, A. +17 more
In November 2020, a new, bright object, eRASSt J234402.9−352640, was discovered in the second all-sky survey of SRG/eROSITA. The object brightened by a factor of at least 150 in 0.2-2.0 keV flux compared to an upper limit found six months previous, reaching an observed peak of 1.76−0.24+0.03 × 10−11 erg cm−2
The GRAVITY young stellar object survey. IX. Spatially resolved kinematics of hot hydrogen gas in the star-disk interaction region of T Tauri stars
Lutz, D.; Sturm, E.; Labadie, L. +58 more
Context. Hot atomic hydrogen emission lines in pre-main sequence stars serve as tracers for physical processes in the innermost regions of circumstellar accretion disks, where the interaction between a star and disk is the dominant influence on the formation of infalls and outflows. In the highly magnetically active T Tauri stars, this interaction…
The IACOB project. IX. Building a modern empirical database of Galactic O9 - B9 supergiants: Sample selection, description, and completeness
Simón-Díaz, S.; Urbaneja, M. A.; de Burgos, A. +1 more
Context. Blue supergiants (BSGs) are key objects for studying the intermediate phases of massive star evolution because they are very useful to constrain evolutionary models. However, the lack of a holistic study of a statistically significant and unbiased sample of these objects has lead to several long-standing questions about their physical pro…
Calibrating mid-infrared emission as a tracer of obscured star formation on H II-region scales in the era of JWST
Leroy, Adam K.; Rosolowsky, Erik; Glover, Simon C. O. +25 more
Measurements of the star formation activity on cloud scales are fundamental to uncovering the physics of the molecular cloud, star formation, and stellar feedback cycle in galaxies. Infrared (IR) emission from small dust grains and polycyclic aromatic hydrocarbons (PAHs) is widely used to trace the obscured component of star formation. However, th…
A 3D view of dwarf galaxies with Gaia and VLT/FLAMES. I. The Sculptor dwarf spheroidal
Salaris, Maurizio; Brown, Anthony G. A.; Helmi, Amina +12 more
We present a new homogeneous survey of VLT/FLAMES LR8 line-of-sight radial velocities (vlos) for 1604 resolved red giant branch stars in the Sculptor dwarf spheroidal galaxy. In addition, we provide reliable Ca II triplet metallicities, [Fe/H], for 1339 of these stars. From this combination of new observations (2257 individual spectra) …