Search Publications
The IACOB project. VI. On the elusive detection of massive O-type stars close to the ZAMS
Meynet, G.; Lennon, D. J.; Herrero, A. +7 more
Context. The apparent lack of massive O-type stars near the zero-age main sequence, or ZAMS (at ages <2 Myr), is a topic that has been widely discussed in the past 40 yr. Different explanations for the elusive detection of these young massive stars have been proposed from the observational and theoretical side, but no firm conclusions have been…
Revived fossil plasma sources in galaxy clusters
Di Gennaro, G.; Brunetti, G.; Shimwell, T. W. +10 more
It is well established that particle acceleration by shocks and turbulence in the intra-cluster medium can produce cluster-scale synchrotron emitting sources. However, the detailed physics of these particle acceleration processes is still not well understood. One of the main open questions is the role of fossil relativistic electrons that have bee…
Metal-poor nuclear star clusters in two dwarf galaxies near Centaurus A suggesting formation from the in-spiraling of globular clusters
Fahrion, Katja; Müller, Oliver; Jerjen, Helmut +7 more
Studies of nucleated dwarf galaxies can constrain the scenarios for the formation and evolution of nuclear star clusters (NSC) in low-mass galaxies and give us insights on the origin of ultra compact dwarf galaxies (UCDs). We report the discovery of a NSC in the dwarf galaxy KKs58 and investigate its properties together with those of another NSC i…
Corona-Australis DANCe. I. Revisiting the census of stars with Gaia-DR2 data
Miret-Roig, N.; Bouy, H.; Sarro, L. M. +5 more
Context. Corona-Australis is one of the nearest regions to the Sun with recent and ongoing star formation, but the current picture of its stellar (and substellar) content is not complete yet.
Aims: We take advantage of the second data release of the Gaia space mission to revisit the stellar census and search for additional members of the youn…
TESS unveils the phase curve of WASP-33b. Characterization of the planetary atmosphere and the pulsations from the star
Mallonn, M.; von Essen, C.; Antoci, V. +4 more
We present the detection and characterization of the full-orbit phase curve and secondary eclipse of the ultra-hot Jupiter WASP-33b at optical wavelengths, along with the pulsation spectrum of the host star. We analyzed data collected by the Transiting Exoplanet Survey Satellite (TESS) in sector 18. WASP-33b belongs to a very short list of highly …
UV and Lyα luminosity functions of galaxies and star formation rate density at the end of HI reionization from the VIMOS UltraDeep Survey (VUDS)
Maccagni, D.; Cimatti, A.; Ilbert, O. +25 more
Context. The star formation rate density (SFRD) evolution presents an area of great interest in the studies of galaxy evolution and reionization. The current constraints of SFRD at z > 5 are based on the rest-frame UV luminosity functions with the data from photometric surveys. The VIMOS UltraDeep Survey (VUDS) was designed to observe galaxies …
The CARMENES search for exoplanets around M dwarfs. Three temperate-to-warm super-Earths
Nagel, E.; Amado, P. J.; Bauer, F. F. +37 more
We announce the discovery of two planets orbiting the M dwarfs GJ 251 (0.360 ± 0.015M⊙) and HD 238090 (0.578 ± 0.021M⊙) based on CARMENES radial velocity (RV) data. In addition, we independently confirm with CARMENES data the existence of Lalande 21185 b, a planet that has recently been discovered with the SOPHIE spectrograph…
High-resolution spectroscopy of flares and CMEs on AD Leonis
Guenther, E. W.; Mutabazi, T.; Jurua, E. +1 more
Context. Flares and coronal mass ejections (CMEs) are important for the evolution of the atmospheres of planets and their potential habitability, particularly for planets orbiting M stars at a distance <0.4 AU. Detections of CMEs on these stars have been sparse, and previous studies have therefore modelled their occurrence frequency by scaling …
Lupus DANCe. Census of stars and 6D structure with Gaia-DR2 data
Bertin, E.; Miret-Roig, N.; Bouy, H. +8 more
Context. Lupus is recognised as one of the closest star-forming regions, but the lack of trigonometric parallaxes in the pre-Gaia era hampered many studies on the kinematic properties of this region and led to incomplete censuses of its stellar population.
Aims: We use the second data release of the Gaia space mission combined with published …
Stellar 3D kinematics in the Draco dwarf spheroidal galaxy
Massari, D.; Helmi, A.; Spina, L. +3 more
Aims: We present the first three-dimensional internal motions for individual stars in the Draco dwarf spheroidal galaxy.
Methods: By combining first-epoch Hubble Space Telescope observations and second-epoch Gaia Data Release 2 positions, we measured the proper motions of 149 sources in the direction of Draco. We determined the line-of-s…