Search Publications
Molecular abundances in the inner layers of IRC +10216
Cernicharo, J.; Daniel, F.; Kahane, C. +3 more
Context. The inner layers of circumstellar envelopes around asymptotic giant branch stars are sites where a variety of processes such as thermochemical equilibrium, shocks induced by the stellar pulsation, and condensation of dust grains determine the chemical composition of the material that is expelled into the outer envelope layers and, ultimat…
Evaporating very small grains as tracers of the UV radiation field in photo-dissociation regions
Joblin, C.; Pilleri, P.; Montillaud, J. +1 more
Context. In photo-dissociation regions (PDRs), polycyclic aromatic hydrocarbons (PAHs) may be produced by evaporation of very small grains (VSGs) by the impinging UV radiation field from a nearby star.
Aims: We quantitatively investigate the transition zone between evaporating VSGs (eVSGs) and PAHs in several PDRs.
Methods: We studied th…
On the nature of the galactic early-B hypergiants
Howarth, I. D.; Urbaneja, M. A.; Negueruela, I. +3 more
Aims: Despite their importance to a number of astrophysical fields, the lifecycles of very massive stars are still poorly defined. In order to address this shortcoming, we present a detailed quantitative study of the physical properties of four early-B hypergiants (BHGs) of spectral type B1-4 Ia+; Cyg OB2 #12, ζ1 Sco, HD…
On the physical structure of IRC +10216. Ground-based and Herschel observations of CO and C2H
Waters, L. B. F. M.; Barlow, M. J.; de Koter, A. +17 more
Context. The carbon-rich asymptotic giant branch star IRC +10 216 undergoes strong mass loss, and quasi-periodic enhancements of the density of the circumstellar matter have previously been reported. The star's circumstellar environment is a well-studied and complex astrochemical laboratory, in which many molecular species have been proved to be p…
Physical conditions in the gas phases of the giant H II region LMC-N 11 unveiled by Herschel . I. Diffuse [C II] and [O III] emission in LMC-N 11B
Poglitsch, A.; Sturm, E.; Lebouteiller, V. +10 more
Context. The Magellanic Clouds provide a nearby laboratory for metal-poor dwarf galaxies. The low dust abundance enhances the penetration of UV photons into the interstellar medium (ISM), resulting in a relatively larger filling factor of the ionized gas. Furthermore, there is very likely a molecular gas reservoir probed by the [C ii] 157 µm…
Gas modelling in the disc of HD 163296
Pinte, C.; Ménard, F.; Duchêne, G. +19 more
We present detailed model fits to observations of the disc around the Herbig Ae star HD 163296. This well-studied object has an age of ~4 Myr, with evidence of a circumstellar disc extending out to ~540 AU. We use the radiation thermo-chemical disc code ProDiMo to model the gas and dust in the circumstellar disc of HD 163296, and attempt to determ…
Nanostructuration of carbonaceous dust as seen through the positions of the 6.2 and 7.7 µm AIBs
Dartois, E.; d'Hendecourt, L.; Brunetto, R. +7 more
Context. Carbonaceous cosmic dust is observed through infrared spectroscopy either in absorption or in emission. The details of the spectral features are believed to shed some light on its structure and finally enable the study of its life cycle.
Aims: The goal is to combine several analytical tools in order to decipher the intimate nanostruc…
Profiling filaments: comparing near-infrared extinction and submillimetre data in TMC-1
Juvela, M.; André, Ph.; Palmeirim, P. +3 more
Context. Interstellar filaments are an important part of the star formation process. In order to understand the structure and formation of filaments, the filament cross-section profiles are often fitted with the so-called Plummer profile function. Currently this profiling is often approached with submillimetre studies, especially with Herschel. If…
An extension of the DUSTY radiative transfer code and an application to OH 26.5 and TT Cygni
Groenewegen, M. A. T.
For the best-studied nearby Galactic asymptotic giant branch (AGB) stars a wealth of observational data is typically available in the form of photometry, often extending into the sub-mm, spectra covering a wide wavelength range, and often also visibility curves. Almost 100 AGB stars and red super giants have been imaged as part of the MESS Hersche…
Spatial variation of the cooling lines in the Orion Bar from Herschel/PACS
Abergel, A.; Bernard, J. -P.; White, G. J. +8 more
Context. The energetics in photo-dissociation regions (PDRs) are mainly regulated by the balance between the heating from the photo-electric effect acting on dust grains, and the cooling via the copious emission of photons in far-infrared lines. The Orion Bar is a luminous and nearby PDR, which presents to the observer an ideal edge-on orientation…