Search Publications
Compressive strength of comet 67P/Churyumov-Gerasimenko derived from Philae surface contacts
Sierks, H.; Blum, J.; Güttler, C. +8 more
Context. The landing and rebound of the Philae lander, which was part of the ESA Rosetta mission, enabled us to study the mechanical properties of the surface of comet 67P/Churyumov-Gerasimenko, because we could use Philae as an impact probe.
Aims: The aim is to approximate the descent and rebound trajectory of the Philae lander and use this …
Observational evidence of third dredge-up occurrence in S-type stars with initial masses around 1 M⊙
Jorissen, A.; Van Winckel, H.; Van Eck, S. +3 more
Context. S stars are late-type giants with spectra showing characteristic molecular bands of ZrO in addition to the TiO bands typical of M stars. Their overabundance pattern shows the signature of s-process nucleosynthesis. Intrinsic, technetium (Tc)-rich S stars are the first objects on the asymptotic giant branch (AGB) to undergo third dredge-up…
Lack of high-mass pre-stellar cores in the starless MDCs of NGC 6334
Zavagno, A.; Louvet, F.; Russeil, D. +6 more
Context. The formation of high-mass stars remains unknown in many aspects. There are two competing families of models to explain the formation of high-mass stars. On the one hand, quasi-static models predict the existence of high-mass pre-stellar cores sustained by a high degree of turbulence. On the other hand, competitive accretion models predic…
Single metal-poor ultra compact dwarf galaxy at one kiloparsec distance from the low-mass elliptical galaxy FCC 47
Fahrion, Katja; Alfaro-Cuello, Mayte; van de Ven, Glenn +7 more
Context. Photometric surveys of galaxy clusters have revealed a large number of ultra compact dwarfs (UCDs) around predominantly massive elliptical galaxies. Their origin is still debated as some UCDs are considered to be the remnant nuclei of stripped dwarf galaxies while others seem to mark the high-mass end of the star cluster population.
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Modelling of Mg II lines in solar prominences
Labrosse, N.; Levens, P. J.
Context. Observations of the Mg II h and k lines in solar prominences with IRIS reveal a wide range of line shapes from simple non-reversed profiles to typical double-peaked reversed profiles, and with many other possible complex line shapes. The physical conditions responsible for this variety are not well understood.
Aims: Our aim is to und…
Hot exozodiacal dust: an exocometary origin?
Augereau, J. -C.; Sezestre, É.; Thébault, P.
Context. Near- and mid-infrared interferometric observations have revealed populations of hot and warm dust grains populating the inner regions of extrasolar planetary systems. These are known as exozodiacal dust clouds, or exozodis, reflecting the similarity with the solar system's zodiacal cloud. Radiative transfer models have constrained the du…
Neutral carbon and highly excited CO in a massive star-forming main sequence galaxy at z = 2.2
Daddi, Emanuele; Aravena, Manuel; Decarli, Roberto +5 more
We used the Plateau De Bure Interferometer to observe multiple CO and neutral carbon transitions in a z = 2.2 main sequence disk galaxy, BX610. Our observation of CO(7-6), CO(4-3), and both far-infrared (FIR) [CI] lines complements previous observations of Hα and low-J CO, and reveals a galaxy that is vigorously forming stars with UV fields (Log(G…
The water line emission and ortho-to-para ratio in the Orion Bar photon-dominated region
Le Petit, F.; Roueff, E.; Lis, D. C. +2 more
Context. The ortho-to-para ratio (OPR) of water in the interstellar medium (ISM) is often assumed to be related to the formation temperature of water molecules, making it a potentially interesting tracer of the thermal history of interstellar gas.
Aims: A very low OPR of 0.1-0.5 was previously reported in the Orion Bar photon-dominated region…
Stellar populations of galaxies in the ALHAMBRA survey up to z ∼ 1. IV. Properties of quiescent galaxies on the stellar mass-size plane
Cenarro, A. J.; López-Sanjuan, C.; Perea, J. +7 more
Aims: We perform a comprehensive study of the stellar population properties (formation epoch, age, metallicity, and extinction) of quiescent galaxies as a function of size and stellar mass to constrain the physical mechanism governing the stellar mass assembly and the likely evolutive scenarios that explain their growth in size.
Methods:…
The blue straggler population of the old open cluster Berkeley 17
Chen, W. P.; Beccari, Giacomo; Vaidya, Kaushar +1 more
Context. Blue straggler stars (BSSs) are observed in Galactic globular clusters and old open clusters. The radial distribution of BSSs has been used to diagnose the dynamical evolution of globular clusters. For the first time, with a reliable sample of BSSs identified with Gaia DR2, we conduct such an analysis for an open cluster.
Aims: We ai…