Search Publications
Horizontal branch morphology: A new photometric parametrization
Salaris, M.; Fontana, A.; Castellani, M. +8 more
Context. Theory and observations indicate that the distribution of stars along the horizontal branch of Galactic globular clusters mainly depends on the metal content. However, the existence of globular clusters with similar metal content and absolute age but different horizontal branch morphologies, suggests the presence of another parameter affe…
Projection effects in galaxy cluster samples: insights from X-ray redshifts
Lovisari, L.; Pacaud, F.; Ramos-Ceja, M. E. +3 more
Presently, the largest sample of galaxy clusters selected in X-rays comes from the ROSAT All-Sky Survey (RASS). Although there have been many interesting clusters discovered with the RASS data, the broad point spread function of the ROSAT satellite limits the attainable amount of spatial information for the detected objects. This leads to the disc…
Comet 67P/Churyumov-Gerasimenko rotation changes derived from sublimation-induced torques
Jorda, L.; Kührt, E.; Keller, H. U. +3 more
Context. The change in rotation period and the orientation of the rotation axis of comet 67P/Churyumov-Gerasimenko (67P) can be deduced with high precision from images taken by the scientific imaging instruments on board the Rosetta mission. Non-gravitational forces are a natural explanation for these data.
Aims: We describe observed changes …
Determining the mass of the planetary candidate HD 114762 b using Gaia
Kiefer, Flavien
The first planetary candidate discovered by Latham et al. (1989, Nature, 339, 38) with radial velocities around a solar-like star other than the Sun, HD 114762 b, was detected with a minimum mass of 11 MJ. The small v sin i ∼ 0 km s-1 that is otherwise measured by spectral analysis indicated that this companion of a late-F su…
Probing X-ray emission in different modes of PSR J1023+0038 with a radio pulsar scenario
Campana, S.; Torres, D. F.; Papitto, A. +3 more
Transitional pulsars provide us with a unique laboratory to study the physics of accretion onto a magnetic neutron star. PSR J1023+0038 (J1023) is the best studied of this class. We investigate the X-ray spectral properties of J1023 in the framework of a working radio pulsar during the active state. We modelled the X-ray spectra in three modes (lo…
Variability of young stellar objects in the star-forming region Pelican Nebula
Chen, W. P.; Herczeg, G. J.; Bhardwaj, A. +2 more
Context. Pre-main-sequence variability characteristics can be used to probe the physical processes leading to the formation and initial evolution of both stars and planets.
Aims: The photometric variability of pre-main-sequence stars is studied at optical wavelengths to explore star-disk interactions, accretion, spots, and other physical mech…
Learning mid-IR emission spectra of polycyclic aromatic hydrocarbon populations from observations
Joblin, C.; Berné, O.; Foschino, S.
Context. The James Webb Space Telescope (JWST) will deliver an unprecedented quantity of high-quality spectral data over the 0.6-28 µm range. It will combine sensitivity, spectral resolution, and spatial resolution. Specific tools are required to provide efficient scientific analysis of such large data sets.
Aims: Our aim is to illustra…
HADES RV Programme with HARPS-N at TNG. X. The non-saturated regime of the stellar activity-rotation relationship for M dwarfs
Rebolo, R.; Ribas, I.; Scandariato, G. +22 more
Aims: We extend the relationship between X-ray luminosity (Lx) and rotation period (Prot) found for main-sequence FGK stars, and test whether it also holds for early M dwarfs, especially in the non-saturated regime (Lx ∝ Prot-2) which corresponds to slow rotators.
Methods: We use the…
Stars and brown dwarfs in the σ Orionis cluster. IV. IDS/INT and OSIRIS/GTC spectroscopy and Gaia DR2 astrometry
Alonso-Floriano, F. J.; Caballero, J. A.; Montes, D. +3 more
Context. Only a few open clusters are as important for the study of stellar and substellar objects, and their formation and evolution, as the young σ Orionis cluster. However, a complete spectroscopic characterisation of its whole stellar population is still missing.
Aims: We filled most of that gap with a large spectroscopic and astrometric …
Effect of radiative heat transfer in porous comet nuclei: case study of 67P/Churyumov-Gerasimenko
Shi, Xian; Blum, Jürgen; Gundlach, Bastian +2 more
Context. Radiative heat transfer occurs in a porous medium, such as regolith on planetary bodies. Radiation enhances the efficiency of heat transport through the subsurface, effecting a strong temperature dependence of thermal conductivity. However, this effect has been omitted in many studies of comet 67P/Churyumov-Gerasimenko (67P).
Aims: W…