Search Publications
Observational evidence for composite grains in an AGB outflow. MgS in the extreme carbon star LL Pegasi
Waters, L. B. F. M.; Mutschke, H.; de Koter, A. +5 more
The broad 30 µm feature in carbon stars is commonly attributed to MgS dust particles. However, reproducing the 30 µm feature with homogeneous MgS grains would require much more sulfur relative to the solar abundance. Direct gas-phase condensation of MgS occurs at a low efficiency. Precipitation of MgS on SiC precursor grains provides a…
XMM-Newton evidence of shocked ISM in SN 1006: indications of hadronic acceleration
Miceli, M.; Bocchino, F.; Decourchelle, A. +5 more
Context. Shock fronts in young supernova remnants are the best candidates for being sites of cosmic ray acceleration up to a few PeV, though conclusive experimental evidence is still lacking.
Aims: Hadron acceleration is expected to increase the shock compression ratio, providing higher postshock densities, but X-ray emission from shocked amb…
The near-infrared detection of PSR B0540-69 and its nebula
De Luca, A.; Mignani, R. P.; Kanbach, G. +4 more
Context. The ~1700 year old PSR B0540-69 in the Large Magellanic Clouds (LMC) is considered the twin of the Crab pulsar because of its similar spin parameters, magnetic field, and energetics. PSR B0540-69 (V ~ 22.5) is also one of the very few pulsars for which both optical pulsations and polarised emission have been measured. Its optical spectrum…
Planetary transit candidates in the CoRoT LRa01 field
Mazeh, T.; Aigrain, S.; Alapini, A. +70 more
Context. CoRoT is a pioneering space mission whose primary goals are stellar seismology and extrasolar planets search. Its surveys of large stellar fields generate numerous planetary candidates whose lightcurves have transit-like features. An extensive analytical and observational follow-up effort is undertaken to classify these candidates.
A…
Solar-like oscillations in the G9.5 subgiant β Aquilae
Grundahl, F.; Kjeldsen, H.; Leccia, S. +3 more
Context. An interesting asteroseismic target is the G9.5 IV solar-like star β Aql. This is an ideal target for asteroseismic investigations, because precise astrometric measurements are available from Hipparcos that greatly help in constraining the theoretical interpretation of the results. The star was observed during six nights in August 2009 by…
Distance to northern high-latitude HI shells
Lallement, R.; Puspitarini, L.
Context. A detailed three-dimensional (3D) distribution of interstellar matter in the solar neighborhood is increasingly necessary. It would allow a more realistic computation of photons and cosmic rays propagation, which is of prime importance for microwave and gamma-ray background emission interpretation, as well as a better understanding of the…
The hypergiant HR 8752 evolving through the yellow evolutionary void
Meynet, G.; Lobel, A.; Kolka, I. +5 more
Context. We study the time history of the yellow hypergiant HR 8752 based on high-resolution spectra (1973-2005), the observed MK spectral classification data, B - V- and V-observations (1918-1996) and yet earlier V-observations (1840-1918).
Aims: Our local thermal equilibrium analysis of the spectra yields accurate values of the effective te…
Ultraviolet extinction toward a quiescent molecular cloud in the Small Magellanic Cloud
Maíz Apellániz, J.; Rubio, M.
Context. The mean UV extinction law for the Small Magellanic Cloud (SMC) is usually taken as a template for low-metallicity galaxies. However, its current derivation is based on only five stars, which renders its universality questionable. More targets with measured extinction laws in the SMC are necessary to determine its possible dependence on p…
Constraining the parameters of globular cluster NGC 1904 from its variable star population
Arellano Ferro, A.; Kains, N.; Bramich, D. M. +3 more
Aims: We present the analysis of 11 nights of V and I time-series observations of the globular cluster NGC 1904 (M 79). Using this we searched for variable stars in this cluster and attempted to refine the periods of known variables, making use of a time baseline spanning almost 8 years. We use our data to derive the metallicity and distance …
[C ii] 158 µm line detection of the warm ionized medium in the Scutum-Crux spiral arm tangency
Goldsmith, P. F.; Langer, W. D.; Pineda, J. L. +1 more
Context. The Herschel HIFI GOT C+ Galactic plane [C ii] spectral survey has detected strong emission at the spiral arm tangencies.
Aims: We use the unique viewing geometry of the Scutum-Crux (S-C) tangency nearl = 30° to detect the warm ionized medium (WIM) component traced by [CII] and to study the effects of spiral density waves on Interste…