Search Publications
The VLT-FLAMES Tarantula Survey. XXXI. Radial velocities and multiplicity constraints of red supergiant stars in 30 Doradus
van Loon, J. Th.; Lennon, D. J.; Herrero, A. +10 more
Aims: The incidence of multiplicity in cool, luminous massive stars is relatively unknown compared to their hotter counterparts. In this work we present radial velocity (RV) measurements and investigate the multiplicity properties of red supergiants (RSGs) in the 30 Doradus region of the Large Magellanic Cloud using multi-epoch visible spectr…
Oxygen isotopic ratios in Martian water vapour observed by ACS MIR on board the ExoMars Trace Gas Orbiter
Grigoriev, A.; Montmessin, F.; Korablev, O. +10 more
Oxygen isotope ratios provide important constraints on the history of the Martian volatile system, revealing the impact of several processes that might fractionate them, such as atmospheric loss into space or interaction with the surface. We report infrared measurements of the Martian atmosphere obtained with the mid-infrared channel (MIR) of the …
Evolutionary phases of merging clusters as seen by LOFAR
Brunetti, G.; Shimwell, T. W.; Cassano, R. +13 more
Massive, merging galaxy clusters often host giant, diffuse radio sources that arise from shocks and turbulence; hence, radio observations can be useful for determining the merger state of a cluster. In preparation for a larger study, we selected three clusters - Abell 1319, Abell 1314, and RXC J1501.3+4220 (Z7215) - making use of the new LOFAR Two…
Spatially resolved spectroscopy of the debris disk HD 32297. Further evidence of small dust grains
Augereau, J. -C.; Pantin, E.; Henning, T. +14 more
Context. Spectro-photometry of debris disks in total intensity and polarimetry can provide new insight into the properties of the dust grains therein (size distribution and optical properties).
Aims: We aim to constrain the morphology of the highly inclined debris disk HD 32297. We also intend to obtain spectroscopic and polarimetric measurem…
No surviving non-compact stellar companion to Cassiopeia A
Justham, Stephen; Do, Tuan; Milisavljevic, Dan +7 more
Massive stars in binaries can give rise to extreme phenomena such as X-ray binaries and gravitational wave sources after one or both stars end their lives as core-collapse supernovae. Stars in close orbit around a stellar or compact companion are expected to explode as "stripped-envelope supernovae", showing no (Type Ib/c) or little (Type IIb) sig…
A new radio molecular line survey of planetary nebulae. HNC/HCN as a diagnostic of ultraviolet irradiation
Kastner, J. H.; Alcolea, J.; Santander-García, M. +3 more
Certain planetary nebulae (PNe) contain shells, filaments, or globules of cold gas and dust whose heating and chemistry are likely driven by UV and X-ray emission from their central stars and from wind-collision-generated shocks. We present the results of a survey of molecular line emission in the 88-236 GHz range from nine nearby (<1.5 kpc) pl…
The Gaia-ESO Survey: Age spread in the star forming region NGC 6530 from the HR diagram and gravity indicators
Gilmore, G.; Franciosini, E.; Randich, S. +33 more
Context. In very young clusters, stellar age distribution is empirical proof of the duration of star cluster formation and thus it gives indications of the physical mechanisms involved in the star formation process. Determining the amount of interstellar extinction and the correct reddening law are crucial steps to derive fundamental stellar param…
Superflares on AB Doradus observed with TESS
Schmitt, J. H. M. M.; Czesla, S.; Robrade, J. +2 more
We present short-cadence data of the ultra-active star AB Dor measured by the Transiting Exoplanet Survey Satellite (TESS). In the TESS light curves of AB Dor, we found numerous flare events in addition to time-variable rotational modulation with an amplitude of up to 7%. We identified eight superflares (releasing more than 1034 erg) an…
Study of CS, SiO, and SiS abundances in carbon star envelopes: assessing their role as gas-phase precursors of dust
Cernicharo, J.; Agúndez, M.; Massalkhi, S.
Aims: We aim to determine the abundances of CS, SiO, and SiS in a large sample of carbon star envelopes covering a wide range of mass loss rates to investigate the potential role that these molecules could play in the formation of dust in the surroundings of the central AGB star.
Methods: We surveyed a sample of 25 carbon-rich AGB stars …
Thermal emission from bow shocks. I. 2D hydrodynamic models of the Bubble Nebula
Green, Samuel; Mackey, Jonathan; Haworth, Thomas J. +2 more
The Bubble Nebula (or NGC 7635) is a parsec-scale seemingly spherical wind-blown bubble around the relatively unevolved O star BD+60°2522. The young dynamical age of the nebula and significant space velocity of the star suggest that the Bubble Nebula might be a bow shock. We ran 2D hydrodynamic simulations to model the interaction of the wind of t…